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1
Dias, Benjamin. "Methanethiol and Cheddar Cheese Flavor." DigitalCommons@USU, 1999. https://digitalcommons.usu.edu/etd/5465.
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The use of slower acid-producing starter bacteria for the production of lower fat Cheddar cheese has lead to milder flavor Cheddar cheeses that lack intense Cheddar notes. The metabolism of methionine leads to the production of methanethiol, which is one of the desirable Cheddar cheese flavor compounds. The influence of NaCl and reduced pH was determined for aminopeptidase, lipase/ esterase, and methanethiol-producing capability in selected lactic acid bacteria and brevibacteria in simulated cheese-like conditions. The activity of each enzyme decreased with NaCl addition and pH reduction to approximate a Cheddar cheese environment (5% NaCl and pH 5.2).
The mechanism for methanethiol production by the starter and adjunct bacteria was also investigated. Different enzyme systems were found to be responsible for methanethiol production in starter lactococci, lactobacilli, and brevibacteria. In the lactococci, enzymes that acted primarily on cystathionine were responsible for methanethiol production from methionine. Lactobacilli also contained cystathionine-degrading enzymes, but these enzymes have properties different from the lactococcal enzymes. Brevibacterium linensBL2 lacked cystathionine-degrading enzymes, but was capable of the direct conversion of methionine to methanethiol.
L-Methionine γ-lyase from B. linens BL2 was purified to homogeneity, and was found to catalyze the α, γ elimination of methionine resulting in the production of methanethiol, α-ketobutyrate, and ammonia. Characterization of the pure enzyme demonstrated that it is pyridoxal phosphate dependent, which is active at salt and pH conditions existing in ripening Cheddar cheese. The addition of either B. linens BL2 or L-methionine γ-lyase to aseptic cheese curd slurries increased methanethiol and total volatile sulfur compound production.
In an attempt to increase methanethiol production and Cheddar cheese flavor in reduced-fat Cheddar cheese, B. linens BL2 was added as a starter adjunct to 60% reduced-fat cheese. Sensory evaluation of the cheese indicated that B. linens BL2 improved the flavor of 60% reduced-fat Cheddar cheese. This suggests that the addition of B. linens BL2 is an alternative to the addition of lactic acid bacteria to improve Cheddar cheese flavor via the metabolism of methionine.
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Fedrick, Ian Allan. "Accelerated ripening of cheddar cheese." Thesis, Queensland University of Technology, 1986. https://eprints.qut.edu.au/35957/1/35957_Fedrick_1986.pdf.
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Various techniques for accelerating mature flavour
development in Cheddar cheese were compared. Control
cheese ( c) was manufactured by using Streptococcus
cremor is AM2, a starter used in normal commercial
manufacture. A combination of S. cremoris AM2 and
Streptococcus lactis C2 Lac- Prt- mutant was used in the
manufacture of test cheeses (M). §._. lactis C2 mutant was grown in glucose broth at 30°c and pH 6 .O for 16 hours, followed by concentration and diafiltration to 1011cfu mL - 1 using microfiltration equipment. The control cheesemilk was inoculated to 6x107 streptococci pe mL with S. cremoris AM2 and the mutant vat cheesemilk to 2x109 per mL with a combination of ~ cremoris AM2 and ~ lactis C2 mutant. The starter population in cheese containing mutant starter was 100 times that in control cheese (1010 compared to 10a). Cheeses were also made with added bacterial neutral proteinase (Neutrase, N) and stored at a0c (a) and 15°c ( 15) for 32 weeks. This resulted in cheese being subjected to the following treatments: ca (control), C15, CNa, CN15, Ma·, M15, MNa, and MN15.
Cheddaring times were slightly reduced and milling
acidities slightly higher in the vat . containing mutant
starter. However the composition of all cheese was
satisfactory. Bacteriological counts, proteolysis,
rheological properties and flavour development of these
cheeses were monitored at regular intervals throughout
maturation. The order of the effectiveness of the
treatment in accelerating ripening was MN15, >M15,>
CN15,> C15,> MNa,> Ma,> CNa,> ca. Cheeses from these
treatments attained the characteristics of control cheese
stored at a0 c (Ca) for 6 months after 1.4, 1.7, 2.0, 2.6, 2.8, 3.2, 4.3 and 6.0 months respectively. Cheese quality was not adversely affected except for bitterness in CN8 cheese and overmaturity in CN15 cheese late in the storage period. The possible mechanisms and relative merits of the various treatments are discussed with special reference to an "active role" theory of starter bacteria in flavour development.
3
Gouldsworthy, Adam M. "Characterisation of protein degradation in Cheddar cheese." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245296.
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Hort, Joanne. "Cheddar cheese : its texture, chemical composition and rheological properties." Thesis, Sheffield Hallam University, 1997. http://shura.shu.ac.uk/19833/.
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Procedures associated with Quantitative Descriptive Analysis were used to identify and subsequently train a panel to quantify the perceived textural attributes of Cheddar cheese. Seventeen types of Cheddar were assessed by the panel for creaminess, crumbliness (fingers), crumbliness (chewing), firmness, graininess, hardness (first bite), hardness (cutting), and springiness. Cluster and Principal Component analyses of the sensory data revealed that the cheese samples could be subdivided into young, mature and extra mature Cheddars in terms of the textural attributes measured. The panel was also able to distinguish between the low fat and genuine Cheddars. The percentage fat, moisture and salt contents and the pH level of the seventeen Cheddar samples were established. An inverse correlation between fat and moisture content and a positive correlation between pH level and salt content were observed. The rheological properties were measured using three tests performed on an Instron Universal Testing Machine - a compression test, a cutting test and a stress relaxation test - and, where appropriate, were reported in terms of true stress and true (Hencky) strain curves. The viscoelastic properties of Cheddar observed during stress relaxation tests were modeled using a Generalised Maxwellian model consisting of two exponential elements and a residual term. Considerable variation in all the rheological properties was observed amongst the Cheddar samples. The rheological parameters did not distinguish between the samples to the same extent as the sensory assessment. However, Cluster Analysis of the rheological data did differentiate between the rheological profiles of the young (mild & medium) and the remaining mature/extra mature samples. The relationships between the textural attributes and the chemical and rheological parameters were investigated. No relationship between chemical composition and texture was identified, but correlations between the rheological parameters and the textural attributes were not uncommon. Multiple regression techniques were employed to construct mathematical models to predict the textural attributes from the rheological data. Successful models were constructed utilising parameters from the compression and cutting tests for all the attributes apart from creaminess. More precise models were constructed for firmness, springiness and crumbliness (fingers) where the action of the instrumental test from which the rheological parameters were obtained resembled the test method used by the panel. The chemical, textural and rheological properties of an English Cheddar were determined at various stages during its ripening period to investigate any changes that occurred. A slight increase in pH was the only chemical change recorded. Progressive changes in the majority of the textural attributes were observed. The most dramatic changes included a decrease in springiness and an increase in creaminess. A changing rheological profile was also observed during maturation, a decreasing strain at fracture being the most notable development. The sequence of changes in both the textural and rheological properties was divided into three fairly distinct phases, the initial stage reflecting the developments necessary before the cheese would be suitable for retail sale and the final stage including the development of the necessary textural attributes characteristic of a Mature English Cheddar. It was evident that the timing of the maturation period was pertinent to the development of textural attributes characteristic of particular maturities of Cheddar cheese. The textural attributes of the maturing Cheddar were also predicted at each stage of maturation using the mathematical models constructed in the initial study. Accurate predictions were made for all the attributes except crumbliness (chewing) and graininess.
5
Beardsley, Richard James. "Growth of E. coli in reduced salt cheddar cheese." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/63231.
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Modern day consumers have become more health conscious and there has been a movement towards reducing sodium intake in their diets. This is due to the risk of the development of hypertension and cardiovascular diseases, as well as other diet related non-communicable diseases associated with excessive sodium intake. Cheddar cheese is one of the most popular cheeses consumed globally and has a relatively high sodium content (2% w/w). A possible way of reducing the sodium content is by making use of replacement salts such as KCl and MgCl2. Partial substitution of NaCl with KCl and MgCl2 has been shown to be possible without compromising on key quality parameters, however very little work has been conducted on the effects of partial salt replacement on the growth of pathogenic bacteria such as E. coli. The first phase of the study focused on replicating the model employed by Grummer & Schoenfuss (2011), to determine equivalent water activities amongst the cheese samples made with different partial salt replacers. The model was adjusted accordingly, and any deviations were noted and taken into account for the second phase of the study. The second phase of the study involved the manufacture of reduced salt cheeses and their inoculation with three different serotypes of non-O157:H7 shiga toxin-producing E. coli. The effect that the alternative sources of salt, as well as reduced NaCl levels had on the growth of E. coli were studied. Physicochemical analyses for the water activity, moisture content and salt-in-moisture (S/M) content of all cheeses were carried out. All three E. coli serotypes were able to grow at water activities greater than 0.95, irrespective of the type of salt treatment used. Even though the Full NaCl control cheeses (2% NaCl) were salted to bring about water activities of less than 0.95, E. coli was still able to grow and increased for 14 days. No differences were found between E. coli growth in the different salt treated cheeses. A correlation was found between the S/M ratio and E. coli growth, with a higher S/M ratio resulting in less E. coli growth. Although water activity is a critical parameter with respect to the inhibition of E. coli growth in cheddar cheese, the S/M ratio was found to be just as crucial a consideration. A combination of hurdle technology is therefore required for ensuring the safety of cheddar cheese products. Salt content, in addition to low pH and low storage temperature work synergistically to exclude the growth of pathogenic bacteria, however much care must be taken when reducing the salt content of cheddar cheese. Reduction of the salt content may interfere with the balance of inhibition of other currently non-problematic bacteria, which may result in the necessity for the replacement of its antimicrobial action. It is therefore apparent that further research on the effects of salt reduction as well as its partial replacement on the growth of E. coli and other pathogens is required, before the implementation of potential salt reduction regulations in cheese products is considered.Dissertation (MSc)--University of Pretoria, 2017.
Food Science
MSc
Unrestricted
6
Huffman, Lee Meryl. "Role of lactose in cheddar cheese manufacture and ripening /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487263399023927.
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Agarwal, Shantanu. "Processing and intrinsic factors affecting the occurrence of calcium lactate crystals in cheddar cheese." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Dissertations/Spring2007/S_Agarwal_040807.pdf.
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Arora, Gulshan. "Studies on peptidases of cheddar cheese-associated Lactobacillus casei species." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70186.
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Preliminary experiments by API ZYM enzyme system showed that Lactobacillus casei (Lb. casei) subspecies contained low proteinase and high aminopeptidase and esterase-lipase activities, which are the desirable traits of microorganisms to be used as starter adjuncts in Cheddar cheese-making. Six strains of Lb. casei (ssp. casei, ssp. rhamnosus, and ssp. pseudoplantarum), selected from superior peptidase and esterase-lipase profiles, were further studied for their amino-, di-, and carboxy-peptidase activities using thirty synthetic substrates. This study revealed useful information towards improving our understanding of the peptidase profiles and probable role of Lb. casei in Cheddar cheese ripening. Although individual strains varied in their specific activities against different substrates, Lactobacillus subspecies generally exhibited high amino- and di-peptidase, relatively weak tripeptidase, but no carboxypeptidase activities. The knowledge gained from these studies helped us selecting two strains (Lb. casei ssp. casei LLG and Lb. casei ssp. rhamnosus S93) with highest amino- and di-peptidase activities for further research. In order to study their enzymatic characteristics and kinetics, aminopeptidase of these two strains were purified to homogeneity by Fast Protein Liquid Chromatography (FPLC). A single monomeric enzyme was shown to be responsible for the entire aminopeptidase activity of the cell-free extracts. This investigation provided new insights and revealed fundamental knowledge about the peptidases of Lb. casei group. In addition, new methodologies were developed for rapid enzyme purification using FPLC system, and evaluation of peptidases by API ZYM enzyme system.
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Poveda, Mariela Fernanda. "EFFECTS OF CHELATING AGENTS ON TEXTURE OF LOWFAT CHEDDAR CHEESE." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1056.
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Effects of two types of chelating agents on proteolysis and texture properties of low fat Cheddar cheese (LFC) were analyzed and compared to full fat Cheddar (FFC) control during ripening for 120 days at 8°C. We hypothesized that chelating agents would bind calcium ions from cheese matrix to give a softer curd due to a decrease of protein-protein interactions and simultaneously increasing moisture content. Cheese milk containing (0.59% fat) was divided into three lots (A, B & C). Sodium citrate (3Na) and disodium EDTA (EDTA) were added to A & B at the rate of (0.02% and 0.2% respectively. C served as control (LFC). Cheesemilk (88°F) was preacidified to pH 6.2 prior to setting using 34 ml chymosin/454 kg and starter culture addition. After cutting, curd was cooked to 96°F for 30 min and held for 10 min. After cooking, the curd was washed, salted, hooped and pressed. FFC was made on subsequence days from same batch of milk by the stirred curd method for Cheddar cheese, cheesemaking was replicated 5 times. Significant difference in moisture content (P˂0.05) was observed between FFC and LFC. Calcium content on the EDTA and 3Na was significantly reduced (P˂0.05) compared to FFC. No significant difference (P˃0.05) in hardness was observed between FFC and LFC at day 7 and 30. After day 30, significant differences (P
10
Kleinhenz, Joseph Patrick. "Medium and higher molecular weight volatile thiols in aged cheddar cheese and their relation to flavor." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1054657696.
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Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xix, 181 p.; also includes graphics (some col.). Includes bibliographical references (p. 158-168). Available online via OhioLINK's ETD Center
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Anjani, Kavya. "Microencapsulation of flavour-enhancing enzymes for acceleration of cheddar cheese ripening." Thesis, View thesis, 2007. http://handle.uws.edu.au:8081/1959.7/32686.
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Commercial flavour-enhancing enzymes were delivered in an encapsulated form to accelerate Cheddar cheese ripening. Polymers such as alginate, chitosan and k- Carrageenan were screened to be used as encapsulant material for microencapsulation of the commercial protease enzyme, Flavourzyme®. Alginate was found to be a suitable polymer for Flavourzyme encapsulation using the Inotech® encapsulator while _-Carrageenan and chitosan were too viscous for extrusion through the encapsulator nozzle. Gelling of alginate-Flavourzyme microcapsules in 0.1M CaCl2 resulted in poor encapsulation efficiency (ranging 17- 18% depending on the alginate concentration). Incorporation of Hi-Maize™ starch or pectin as filler materials into the alginate-Flavourzyme encapsulation matrix to increase encapsulation efficiency by minimising porosity also resulted in poor encapsulation efficiency.
An alternative approach to the modification of the cationic gelling solution, by adding chitosan, significantly increased the encapsulation efficiency to 70-88% and produced mostly spherical capsules with an average diameter of 500_m. Encapsulation efficiency increased with an increase in chitosan concentration from 0.1 to 0.3% (w/v) in the cationic gelling solution of 0.1M CaCl2. Though gelling of alginate-Flavourzyme microcapsules in gelling solution of 0.1M CaCl2 containing 0.3% (w/v) chitosan resulted in higher encapsulation efficiency, a chitosan concentration of 0.1% (w/v) was chosen for further work as higher concentrations of chitosan in the gelling solution resulted in aggregation of capsules during formation. Gelling time of 10 min and alginate concentrations in the range 1.6 to 2.0% (w/v) were found to be optimal encapsulation parameters for Flavourzyme encapsulation while 2.0% (w/v) solution of trisodium citrate was found to be optimal for in vitro release of encapsulated enzymes for measurement of enzyme activity. Flavourzyme capsules stored frozen or freeze-dried were shelf stable for at least 10 weeks retaining about 80% of the initial enzyme activity as opposed to retention of 25-34% activity in air-dried capsules. Leakage of encapsulated Flavourzyme prepared from 1.6% (w/v) alginate was slightly higher than those prepared from 1.8 and 2.0% (w/v) alginate in cheese milk. Flavourzyme-alginate capsules prepared from 1.6, 1.8 and 2.0% (w/v) alginate retained over 70% of the initial enzyme activity under simulated cheese-press pressure. Concentration of alginate had no significant effect (p > 0.05) on the
retention of encapsulated Flavourzyme when the capsules were pressed for 4h; however when the simulated cheese press duration increased to 8 and 16h the retention of encapsulated Flavourzyme was significantly higher (p [less than] 0.01) in capsules produced from 2.0% (w/v) alginate. Incorporation of encapsulated enzymes into the milk prior to rennetting resulted in an even distribution of capsules in the cheese matrix compared to aggregation of capsules, when added to milled curd prior to salting. All cheeses; control with no added enzymes and experimental cheeses with free and encapsulated Flavourzyme and/or Palatase showed higher levels of moisture and lower levels of fat compared to standard Cheddar cheese due to the variation in the manufacturing protocol. There
was no significant difference (p > 0.05) in fat and final pH between control and experimental cheeses and there was no difference in the numbers of coliforms, E.coli, Salmonella, Listeria, coagulase positive staphylococci, Bacillus cereus, yeast and moulds in control or experimental cheeses. Increased and prolonged proteolysis was observed in cheeses with encapsulated Flavourzyme showing increased release of several peptides, also with the formation of new peptides absent in the control cheese with no added enzymes. Accumulation of high molecular weight/hydrophobic peptides was higher in cheeses with free Flavourzyme followed by cheeses with encapsulated Flavourzyme. Concentration of water-soluble peptides increased with the increase in the concentration of encapsulated Flavourzyme in the cheese. Concentration of water-insoluble peptides was higher in control cheese compared to cheeses with encapsulated Flavourzyme even after 180 days ripening. After 30 days of ripening, concentration of most free amino acids was about 3 times greater in cheeses with encapsulated Flavourzyme than in control and about 7 times higher after 90 days ripening. Concentration of total amino acids was consistently higher in cheeses with encapsulated Flavourzyme compared to control. Cheese grading scores for body, texture and appearance of all cheeses with encapsulated enzymes were lower than control and free enzyme treated cheeses during the entire grading period of about 100 days due to crumbly and pasty texture.
Control and cheeses with added Flavourzyme received high overall score for flavour. Flavour score of cheese with encapsulated Flavourzyme at a concentration of 0.75 LAPU/g milk protein was higher than all cheeses around 50 days with better overall flavour score until about 94 days ripening with improved flavour and elimination of bitterness. However the flavour of enzyme treated cheeses deteriorated with time and the control cheese scored the highest for flavour. Though increased concentration of free fatty acids was detected in cheeses treated with encapsulated lipase; Palatase, these cheeses developed rancid, unpleasant, strong lipolytic flavours as early as 55 days ripening.
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Royyala, Vishal Kumar. "Product formulation and consumer acceptability of processed cheese made with different types of cocoas and chocolates & product formulation and quantitative descriptive analysis of aged cheddar cheese with different types of chocolate inclusions." Master's thesis, Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-11062008-133332.
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Amenu, Boka. "Environmental and dietary effects on milk composition and cheddar cheese yield /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18661.pdf.
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Goosen, Claire. "Consumer acceptance of cheddar cheese : intrinsic, extrinsic and socio-demographic influences." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86490.
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Thesis (MAgricAdmin)--Stellenbosch University, 2014.ENGLISH ABSTRACT: The objective of this study was to determine the sensory characteristics of Cheddar cheese that drive consumer acceptance. In addition, it investigated whether specific sensory profiles would satisfy specific consumer segments to ultimately facilitate greater acceptance and consumption of Cheddar cheese. A trained panel applied descriptive sensory analysis (DSA) to characterise the sensory attributes of six commercially produced cheeses ranging in maturity from 1 to 32 months. The cheese samples were differentiated by appearance, aroma, flavour and textural attributes. A consumer panel comprising of 115 target consumers rated preference for the cheeses on a 9-point hedonic scale. Moreover consumers completed a screener designed to collect socio-demographic information and opinions on cheese and cheese products. Instrumental colour analysis was performed on the cheese samples and in-depth consumer opinions and attitudes towards cheese were examined using the focus group technique. Analysis of variance (ANOVA) was conducted on the sensory and instrumental data, as well as the consumer liking and perception data. Additionally, a t-test was performed at a 5% significance level to determine the direction of the difference between the mean values. Multivariate analyses were performed on the sensory and consumer data to determine whether relationships existed between sample attributes and consumer liking. Consumer acceptability scores were segmented by agglomerative hierarchical clustering (AHC) using Ward’s test. ANOVA was performed on the consumer data per cluster for colour liking, texture liking, flavour liking and overall liking. Partial least squares regression (PLS) was performed in an attempt to relate consumer degree of liking data, the socialdemographic and attitudinal data, as well as the sensory and instrumental data. The younger cheeses; Gouda at one month, Edam at two months and Cheddar at 4 months were characterised as glossy, with a buttery and creamy aroma; creamy flavour, salty and slightly sour taste combined with lingering cheese flavour. Textures were described as creamy, springy and rubbery. Sensory attributes of visible white crystals, moisture seepage, brothy and Cheddar aromas; brothy, Cheddar and prickle flavours together with textural attributes of firm, hard, crumbly, grainy and teeth-coating characterised the aged Cheddar cheeses. Flavour development was not progressive as the cheeses aged and atypical flavour development was identified in the Cheddar cheese aged to 8 and 15 months, respectively. Flavour followed by price and convenience drive cheese purchase amongst this group of consumers. From a sensory perspective, glossy appearance, a red hue and yellow colour drive cheese colour liking. Texture liking is driven by springy and hard attributes. Flavour liking is driven by cooked milk, buttery and creamy aroma and creamy flavour. Finally overall cheese liking is driven by glossy appearance; cooked milk, buttery and creamy aroma; creamy flavour; springy and creamy texture; specific instrumental colour values, as well as fat, moisture and salt content. Three clusters per variable of colour, texture, flavour and overall liking of cheese were identified through segmentation performed on the preference data. Results indicate that consumers are not homogenous in their sensory requirements, attitudes and behaviour towards cheese. Based on the consumer preference for specific sensory characteristics of cheese, consumer segments can be identified and cheese can be optimised to satisfy these sensory requirements.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was eerstens om te bepaal watter spesifieke sensoriese eienskappe van Cheddarkaas verbruikersaanvaarbaarheid dryf, en tweedens om verbruikersdata te segmenteer ten einde vas te stel of verskillende verbruikersegmente verskillende voorkeure het wat betref Cheddarkaas. Kennis hiervan sal uiteindelik bydra tot verhoogde verbruikerstevredentheid, en dus verhoogde verkope van Cheddarkaas op die plaaslike mark. Beskrywende sensoriese analise en ’n opgeleide paneel is gebruik om die sensoriese eienskappe van ses kommersiële kaas variante te bepaal. Instrumentele kleuranalise is ook bepaal. Die monsters kaas het gewissel in ouderdom (van 1 tot 32 maande veroudering), asook in voorkoms, aroma, geur, smaak en teksturele eienskappe. ’n Verbruikerspaneel bestaande uit 115 individue het die voorkeur en aanvaarbaarheid van die ses variante kaas ge-evalueer deur gebruik te maak van die 9-punt hedoniese skaal. Sosio-demografiese inligting en verbruikeropinies betreffende kaas is ook versamel. Ten laaste is die fokusgroep tegniek gebruik om in-diepte inligting te verkry wat betref verbruikeropinies en –houdings ten opsigte van Cheddarkaas. Analise van variansie (ANOVA) is op sensoriese, instrumentele en verbruikersdata toegepas. T-toets is by ‘n betekenispeil van 5% uitgevoer om te bepaal of daar per eienskap betekenisvolle verskille tussen monstergemiddeldes was. Meerveranderlike analise is uitgevoer op die sensoriese en verbruikerdata ten einde te bepaal of spesifieke sensoriese produkeienskappe verbruikersvoorkeur dryf. Ward se statistiese groepering is gebruik om te bepaal of die verbruikers in verskillende voorkeursegmente gegroepeer kan word. Hierna is ANOVA op elke segment uitgevoer ten einde per segment verbruikersvoorkeur van die onderskeie produkte te bepaal wat betref voorkoms, geur en tekstuur. Meervoudige regressie analise is toegepas om die verwantskap tussen verbruikervoorkeur-, houding- en sosio-demografiese eienskappe van die verbruikers te bepaal, asook tussen die sensoriese en instrumentele produkeienskappe. Die kase wat vir ‘n kort tydperk verouder is, m.a.w. Gouda, Edam en Cheddar na 4 maande veroudering is beskryf as glansend, met ‘n ryk botter en romerige aroma, romerige geur, sout en effense suur smaak, asook ‘n standhoudende kaasgeur. Teksturele eienskappe van hierdie drie kaassoorte is beskryf as romerig, veerkragtig en effe rubberig. Die Cheddar kase wat langer verouder is, het tekens getoon van sigbare wit kristalle en sinerese op die kaasoppervlak, ‘n prikgevoel op die tong, asook sopagtige (“brothy”) en Cheddaragtige aromas en geure. Die teksturele eienskappe van die verouderde Cheddar kase is beskryf as ferm, hard, krummelagtig en greinerig, asook met’n geneigdheid van die kaas om aan die tande vas te kleef. Geurontwikkeling het nie progressief plaasgevind soos die kase verouder het nie. Die Cheddar kase wat onderskeidelik vir 8 en 15 maande verouder is, het atipiese geurontwikkeling getoon. Belangrike faktore wat tydens die aankoop van kaas’n rol speel, en dus voorkeur dryf is eerstens geur, tweedens prys en derdens produk-gemak. Sensoriese aspekte wat voorkeur dryf, is ‘’n glansende voorkoms en effe rooierige-gelerige kleur. Tekstuur voorkeure sluit in veerkragtiheid en hardheid, terwyl geur voorkeure die volgende insluit: romerige, botterige en melk aromas, asook ‘n romerige geur. In die geheel gesien, dryf die volgende eienskappe dus verbruikersvoorkeur: kaas met ‘n glansende voorkoms, geure soos botteragtig, roomagtig en melkerig en teksture soos veerkragtig en romerig. Voedinstofinhoud beȉnvloed ook verbruikersvoorkeur, nl. soutinhoud, vetinhoud en voginhoud. Segmentasie van verbruikersdata het getoon dat die onderskeie verbruikersegmente nie ooreenstem wat betref hul verbruikersvoorkeure, houdings en persepsies van kaassorte nie. Die resultate het egter spesifike sensoriese rigtingwysers geidentifiseer wat die bedryf kan gebruik om kaas te produseer vir elk van die onderskeie marksegmente.
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Anjani, Kavya. "Microencapsulation of flavour-enhancing enzymes for acceleration of cheddar cheese ripening." View thesis, 2007. http://handle.uws.edu.au:8081/1959.7/32686.
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Thesis (Ph.D.)--University of Western Sydney, 2007.A thesis submitted to the University of Western Sydney, College of Health and Science, Centre for Plant and Food Science, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographical references.
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Reinbold, Robert S. "Factors Affecting Moisture Distribution in 290-Kilogram Stirred-Curd Cheddar Cheese Blocks." DigitalCommons@USU, 1991. https://digitalcommons.usu.edu/etd/5369.
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The purpose of this dissertation was to study factors affecting moisture distribution in 290-kilogram stirred-curd Cheddar cheese blocks cooled in stainless steel hoops. Uneven moisture distribution within blocks may create cheese with variable texture and flavor, which can be extremely costly to the producer. The effects of temperature, pH, and vacuum treatment on moisture distribution were investigated. Temperature, pH, moisture, and pressure profiles were presented. Also, comparisons were made between temperature profiles of 290- kilogram stirred-curd Cheddar cheese blocks cooled in stainless steel and in plywood hoops, as well as between temperature profiles of 66-kilogram Swiss cheese blocks cooled in cardboard and in plastic boxes.
Moisture transferred from high to low temperature in the cheese blocks. Moisture may have transferred in response to thermally induced curd moisture-holding capacity gradients in the cheese blocks. Moisture also may have transferred in the cheese blocks by a mechanism similar to thermo-osmosis of liquids in porous solids.
The cheese in the plywood or cardboard insulating materials cooled more uniformly than the cheese in the stainless steel or plastic containers. More uniform cooling of the cheese produced more uniform moisture distribution in the cheese blocks. Recommendations were made to help the cheesemaker produce cheese with even moisture distribution.
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Venter, Tania. "Modelling the catabolite and microbiological profile of cheddar cheese manufactured from ayrshire milk." Thesis, Bloemfontein : Central University of Technology, Free State, 2010. http://hdl.handle.net/11462/127.
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Thesis (D. Tech.) -- Central University of Technology, Free State, 2010Branded dairy products have lately become a global trend. As a result of this, the origin of the milk used in the manufacturing of branded cheeses must be declared by the producer, since it is known that these products are highly adulterated with foreign milk. In South Africa, branded Ayrshire Cheddar cheese has become highly popular due to its unique organoleptic properties and in light of claims that it ripens much faster than cheese made from other milk (not including Ayrshire). This study was therefore directed to investigate the unique properties of branded Ayrshire Cheddar cheese versus Cheddar cheese manufactured from a mixture of other breeds’ milk (not including Ayrshire milk) and to establish a catabolite profile for each cheese type. The outlay of the thesis was constructed into six chapters each with its own outcomes. The first chapter focused on the variations between the two Cheddar cheese batches (produced from Ayrshire and other breeds’ milk) with regards to organic acid, selected chemical parameters and starter microbiotia. In the following three chapters mathematical models were developed that would predict organic-; fatty and amino acid fluxtuations respectively in the cheese made from Ayrshire and other milk. In the last chapter two artificial neural networks were designed with the two starter organisms, Lactococcus lactis and Streptococcus thermophilus as variable indicator respectively. Thirty-two cheese samples of each batch (pure Ayrshire (4) / mix breed with no Ayrshire (4)) were ripened and samples were analysed under the same conditions on the following days after production: 2, 10, 22, 36, 50, 64, 78, and 92. In the subsequent chapters, the following analysis were done on each day of analysis: organic acid by means of high performance liquid chromatography (HPLC); fatty acids by means of Gas Chromatography Mass Spectometry (GCMS); amino acids by means of GC-MS; microbial analysis by means of traditional methods, total DNA extraction and polymerase chain reaction (PCR); and standard chemical analysis for moisture, NaCl and pH. In the first research chapter, the minimum and maximum (min/max) values, standard deviations and proposed rel X values of organic acids were evaluated in Ayrshire and the mixed-breed Cheddar cheese, and showed that isovaleric acid is the organic acid with the least variation relative to concentration in both cheeses and it was assumed that this organic acid is the most effective indicator of cheese uniformity. Clear differences in organic acids, chemical variables and starter micro-organisms were also evident in the two cheese batches. Results obtained from the regression models which was defined for each organic -; amino - and fatty acid by means of mathematical equations can be used by the manufacturer to achieve i.e. the selection of cheese for specialist lines, the early exclusion of defective cheeses, and the establishment of brand origin (Ayrshire vs. mixed-breed Cheddar cheeses). The regression graphs also illustrate unique flux patterns in Ayrshire and the mixed-breed in terms of organic -, fatty -, and amino acid content. In the last chapter, the discrimination between the two batches was respectively done via artificial neural network (ANN) modelling of Lactococcus lactis and Streptococcus thermophilus as indicator organisms. The ANN consisted of a multilayered network with supervised training arranged into an ordered hierarchy of layers, in which connections were allowed only between nodes in immediately adjacent layers. The construction thereof allowed for two output nodes, connected to an input layer consisting of two nodes to which the inputs were connected. In both cheeses the results from the ANN showed acceptable classification of the cheeses based on the counts of L. lactis and S. thermophilus.
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Doxey, David Gary. "An Observational Study of Physicochemical Changes in Cheddar Enzyme-Modified Cheese During Incubation." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/8266.
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This study is an observation of the various physicochemical changes that occur in enzyme-modified cheese (EMC) during the incubation step of production. The purpose of this study was an attempt to gain a better understanding of the changes that occur due to enzymatic reactions during EMC production. A standard EMC batch was prepared with the addition of two exogenous enzymes, a lipase and a protease (LP). Two additional treatment batches had either only a lipase (L) or a protease (P) added individually. Batches were prepared in duplicate with each replicate performed on different days. Each batch was incubated at 42±0.5°C in a water bath and was monitored for changes in pH, water activity, viscosity, water-soluble nitrogen, water-soluble free amino acids, titratable acidity, and visual observations, every two hours over a standard incubation time of 24 hours. Changes in pH showed little to no change in the P batches, while both the LP and L batches showed a decrease over time, very similar to each other. Changes in water activity showed a slight decrease over time in all batches from 0.98 to 0.94-0.97. However, because these changes were so small and a considerable amount of variation was found between replicate batches, water activity was likely a less practically significant method for measuring enzyme hydrolysis. Changes in viscosity were significantly different between all batches at different points and the L batches produced some very unique changes in viscosity. Changes in water-soluble nitrogen showed unexpected higher levels in the LP batches than the P batches. Changes in water-soluble free amino acids showed a significant impact that the protease had on the liberation of free amino acids. Changes in titratable acidity showed an increase in the LP batches and an apparent additive effect from both enzymes when combined. Monitoring these physicochemical properties in the different treatments indicated the changes that were brought about by the enzymes and may be repeated by manufacturers to identify production end-points.
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Bland, Julie H. "Jersey milk suitability for Cheddar cheese production : process, yield, quality and financial impacts." Thesis, University of Reading, 2015. http://centaur.reading.ac.uk/40665/.
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The aim of this study was to first evaluate the benefits of including Jersey milk into Holstein-Friesian milk on the Cheddar cheese making process and secondly, using the data gathered, identify the effects and relative importance of a wide range of milk components on milk coagulation properties and the cheese making process. Blending Jersey and Holstein-Friesian milk led to quadratic trends on the size of casein micelle and fat globule and on coagulation properties. However this was not found to affect the cheese making process. Including Jersey milk was found, on a pilot scale, to increase cheese yield (up to + 35 %) but it did not affect cheese quality, which was defined as compliance with the legal requirements of cheese composition, cheese texture, colour and grading scores. Profitability increased linearly with the inclusion of Jersey milk (up to 11.18 p£ L-1 of milk). The commercial trials supported the pilot plant findings, demonstrating that including Jersey milk increased cheese yield without having a negative impact on cheese quality, despite the inherent challenges of scaling up such a process commercially. The successful use of a large array of milk components to model the cheese making process challenged the commonly accepted view that fat, protein and casein content and protein to fat ratio are the main contributors to the cheese making process as other components such as the size of casein micelle and fat globule were found to also play a key role with small casein micelle and large fat globule reducing coagulation time, improving curd firmness, fat recovery and influencing cheese moisture and fat content. The findings of this thesis indicated that milk suitability for Cheddar making could be improved by the inclusion of Jersey milk and that more compositional factors need to be taken into account when judging milk suitability.
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Khosrowshahi-asl, A. "A study of the interaction of heat and concentration in the preparation of milk for cheesemaking." Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380834.
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Eccles, Robert. "Relationship of the non-volatile, water-soluble fraction of cheddar cheese to its quality." Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321280.
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Tansman, Gil Fils. "Exploring the nature of crystals in cheese through X-ray diffraction." ScholarWorks @ UVM, 2014. http://scholarworks.uvm.edu/graddis/321.
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The optimization of powder x-ray diffraction (PXRD) for the study of cheese crystals was the focus of this study. A survey was conducted of various manifestations of calcium lactate crystals on the rindless surface and within mechanical openings of Cheddar cheese using PXRD. The diffraction reference card database contained a card that was entitled calcium lactate pentahydrate and corresponded to some of the crystalline material found on the cheeses. Diffractions patterns generated from other samples of crystalline material revealed the existence of an unknown crystal that resembled and behaved similarly to calcium lactate pentahydrate, but did not match the reference card.
The existence of two enantiomeric variants of calcium lactate pentahydrate had been firmly established; an experiment was thus designed to determine if the unknown diffraction pattern represented one enantiomeric form, and if the ambiguously named reference card represented the other. This experiment demonstrated that the existing reference card corresponded to calcium DL-lactate pentahydrate and that the unknown diffraction pattern was generated from calcium L-lactate pentahydrate. This study resulted in the proposal of a new reference card for calcium L-lactate pentahydrate and the proposed renaming of the existing card to calcium DL-lactate pentahydrate. This discovery allows the rapid identification of both forms of calcium lactate that form in and on cheese.
In order to conduct the survey and experiment that are described above, the PXRD method needed to be adjusted for use with cheese crystals. Samples of cheese crystals pose a particular challenge because they are often composed of high proportions of moisture, fat, protein, and other amorphous material; these all disrupt the efficient diffraction of crystals and thus needed to be removed or minimized. The removal of water from samples is a particular challenge because some cheese crystals contain water of hydration that may be driven off in the process, thereby destroying the crystals. A protocol for the preparation of cheese samples for PXRD was consequently developed.
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Cilliers, Frans Pieter. "A biochemical study of the effect of ultraviolet treatment on bovine milk and Cheddar cheese." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97803.
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Thesis (PhD)--Stellenbosch University, 2015.ENGLISH ABSTRACT: This study describes: 1. The evaluation of a novel, patented thin-film, turbulent-flow Ultravioletdisinfection system as an alternative processing method to thermal pasteurisationfor the disinfection of bovine milk. 2. The microbial, biochemical and sensory characterization of bovine milk treated by heat and Ultraviolet light and then used for the commercial production of Cheddarcheese. 3. The microbial, biochemical and sensory characterization of commercial Cheddarcheese produced from bovine milk treated by heat and Ultraviolet light.
AFRIKAANSE OPSOMMING: Hierdie studie beskryf: 1. Die evaluasie van ‘n unieke, gepatenteerde dun-film, turbulente vloeiUltravioletsisteem as ‘n alternatief vir termiese pasteurisasie vir die behandeling van beesmelk. 2. Die mikrobiologiese-, biochemiese- en sensoriese karakterisasie van beesmelkbehandel met hitte en Ultravioletlig gebruik vir kommersiële produksie van Cheddar kaas. 3. Die mikrobiologiese-, biochemiese- en sensoriese karakterisasie van kommersiëleCheddarkaas vervaardig van beesmelk wat behandel is met hitte en Ultravioletlig.
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Subramanian, Anand Swaminathan. "Monitoring Flavor Quality, Composition and Ripening Changes of Cheddar Cheese Using Fourier-Transform Infrared Spectroscopy." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243949818.
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Lance, Rebekah M. "Effect of Adjunct Cultures, Sodium Gluconate, and Ripening Temperature on Low-Fat Cheddar Cheese Flavor." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1004.
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Low-fat Cheddar cheese flavor is different from full-fat Cheddar cheese and is not acceptable to many consumers. This 2-part experiment was designed to examine effects adjunct cultures have on low-fat Cheddar cheese flavor as determined through descriptive analysis and consumer feedback.
In Part 1, low-fat (5%) Cheddar cheese was produced in duplicate, using 6 combinations of DVS850, LH32, CR540, CRL431, Emfour, and CR319 bacterial cultures. Due to a previously observed positive effect by sodium gluconate on low-fat cheese flavor, each replicate was split into treatments of 0.0% and 0.8% sodium gluconate. Each of these treatments was then split into ripening temperature treatments: 6°C for 21 ± 1 wk; or 6°C for 3 wk, 10°C for 8 wk, and 6°C for 10 wk. Cheese was tasted first by an informal panel. The 4 treatment combinations for the control cheese and the CR540 (a Lactococcus lactis ssp. and Lactobacillus ssp. blend) cheese, along with all culture combinations containing sodium gluconate and ripened only at 6°C, were selected for descriptive analysis. Some statistically significant differences in culture treatment were observed. Sodium gluconate addition had a positive influence on flavor while elevated ripening temperature resulted in undesirable flavor notes. Low-fat (5%) Cheddar cheese with the CR540 adjunct with and without sodium gluconate was evaluated in a consumer taste panel with commercial full-fat (33% fat) and commercial reduced-fat (25% fat) Cheddar cheese. The low-fat cheeses were not significantly different from the commercial reduced-fat, indicating comparable cheese.
Part 2 involved making Cheddar-like cheese with non-Cheddar adjunct cultures, using the same process as Part 1. Sodium gluconate was again added but elevated ripening temperature was not included. Each treatment was also divided into a sodium treatment, full salt (2%) and reduced salt (1.5%). After 2 mo of storage at 6°C, cheese was tasted by an informal panel and found to be bitter because of the starter culture used. A culture was added to the second replicate of the experiment to reduce bitterness. This adjunct was found to be somewhat effective in reducing bitterness but not entirely. Descriptive analysis was performed on the high salt level treatments for both replicates. Some difference was observed among cultures and sodium gluconate treatments; however, no acceptable cheese was produced due to bitterness in both replicates. Sodium treatments were not analyzed.
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Soeryapranata, Elly. "Characterization of aminopeptidase N and endopeptidases E, O, O2, O3 from Lactobacillus helveticus WSU19, a Lactobacilli with industrial significance." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Dissertations/Summer2005/e%5Fsoeryapranata%5F071205.pdf.
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Franssen, Lauren Rene. "Antimicrobial properties and diffusion modeling of preservative-containing whey protein films and coatings on cheddar cheese /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Ortakci, Fatih. "Contribution of a Novel Obligatory Heterofermentative Nonstarter Lactobacillus Species to Late Gassy Defect in Cheddar Cheese." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4255.
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This study sought to determine whether a recently isolated slow-growing nonstarter lactic acid bacterium, Lactobacillus wasatchii sp. nov., could be implicated in late gassy defect in Cheddar cheese. I demonstrated that Lb. wasatchii grows readily in the laboratory under cheese-like stress conditions of 5% salt and pH 5.2, and has the potential to survive pasteurization. Lactobacillus wasatchii can co-utilize ribose and galactose to maximize its growth. Due to being an obligatory heterofermentative, Lb. wasatchii produces CO2 whenever it ferments a hexose such as galactose.
A second investigation extended these findings by examining the growth and gas forming characteristics of Lb. wasatchii in Cheddar cheese. The optimum growth of Lb. wasatchii and highest levels of gas production were observed in cheese supplemented with ribose plus galactose, and stored at 12°C rather than 6°C. Lactobacillus wasatchii also grew readily and produced gas in Cheddar cheese even without added ribose and galactose, which corresponds with the ability of Lb. wasatchii to grow on starter cell lysate. A challenge still remains of how to easily enumerate Lb. wasatchii in cheese with a higher background population of other nonstarter lactic acid bacteria.
The third set of experiments explored the consequences on growth and gas production of Lb. wasatchii in Cheddar cheese made with Streptococcus thermophilus. Using St. thermophilus in cheesemaking results in galactose accumulation, which Lb. wasatchii then can utilize for growth, causing release of CO2 with the end result of having blown Cheddar cheese. Results showed Lb. wasatchii or similar nonstarter lactic acid bacteria are likely to be particularly problematic in cheesemaking involving starter or adventitious St. thermophilus.
From these observations, it was concluded that Lb. wasatchii is a contributor to late gassy defect in Cheddar cheese and may be widely present as part of the nonstarter lactic bacteria population but has been undetected up until now. The late gassy defect is more pronounced at temperatures used for accelerated ripening of cheese and when there are substantial residual levels of galactose in the cheese. Thus, researchers and cheese manufacturers now must consider slow-growing obligatory heterofermentative nonstarter lactic acid bacteria when dealing with late gassy defect in cheese.
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Gummalla, Sanjay. "Tryptophan Catabolism by Lactobacillus spp. : Biochemistry and Implications on Flavor Development in Reduced-Fat Cheddar Cheese." DigitalCommons@USU, 1998. https://digitalcommons.usu.edu/etd/5454.
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Amino acids derived from the degradation of casein in cheese serve as precursors for the generation of key flavor compounds. Microbial degradation of tryptophan (Trp) is thought to promote formation of aromatic compounds that impart putrid fecal or unclean flavors in cheese, but pathways for their production have not been established. This study investigated tryptophan catabolism by Lactobacillus casei LC301 and LC202 and Lactobacillus helveticus CNRZ32 and LH212 cheese flavor adjuncts in carbohydrate starvation (pH 6.5, 30 or 37°C, no sugar) and cheese-like conditions (pH 5.2, 4% NaCl, 15°C, no sugar). Enzyme assays of cell-free extracts revealed both species of Lactobacillus catabolized tryptophan to indole lactic acid via indole pyruvic acid through transamination followed by dehydrogenation. Micellar electrokinetic capillary chromatography of culture supernatants showed these enzymes also catalyzed the reverse reactions, i.e., conversion of indole lactic acid to tryptophan. Tryptophan decarboxylase activity was detected in Lactobacillus cell-free extracts, but tryptamine was not detected in culture supernatants. Analysis of culture supernatants showed that tryptophan metabolism in Lactobacillus casei did not differ between the two conditions of incubation as it did in Lactobacillus helveticus LH212 and CNRZ32. Lactobacillus helveticus LH212, for example, did not catabolize Trp in carbohydrate starvation but did in cheese-like conditions. While cells of L. helveticus CNRZ32 did not catabolize Trp in either condition, they catabolized indole pyruvic acid to only Trp in carbohydrate starvation and to both Trp and indole lactic acid in cheese-like conditions. Micellar electrokinetic capillary chromatography of culture supernatants incubated under either starvation or cheese-like conditions showed Lactobacillus casei strains produced more indole lactic acid, and Lactobacillus helveticus strains favored tryptophan anabolic reactions. Based on the results obtained in this study, a putative pathway for the catabolism of tryptophan by lactobacilli in cheese is proposed.
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Wadhwani, Ranjeeta. "Investigating the Strategies to Improve the Quality of Low-Fat Mozzarella and Cheddar Cheeses." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1154.
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Low-fat cheese faces great challenges associated with its texture being hard and rubbery, desirable flavors being missing, color being undesirably intense and translucent appearing, and melting being improper. In an effort of improving the quality of low-fat cheeses, several strategies have been tried to accomplish three major objectives, 1) improving the melting and baking properties of low-fat Mozzarella cheese, 2) improving the color of low-fat Cheddar cheese, and 3) investigating the feasibilities of enriching low-fat Cheddar cheese with dietary fibers.
For objective 1, 4 batches of low-fat Mozzarella cheese with target fat of 6.0%, 4.5%, 3.0%, and 1.5% were made using a stirred curd method, comminuted in a bowl chopper and mixed with different levels of melted butter (0.0, 1.5, 3.0, and 4.5% (wt/wt), respectively) before pressing. This would made the cheese that had increased free oil, increased melting, and improved baking as the level of added butter increased. The added butterfat was present as free fat along the curd particle junctions as shown by laser scanning confocal microscopy while the fat droplets originating from the milk were distributed within the protein matrix of the cheese. In objective 2, consumer tests and flavor profile analysis were performed on 4 commercial brands of full-fat Cheddar cheese and 9 low-fat Cheddar cheeses manufactured at Utah State University with different colors. Low-fat cheeses were rated different (P < 0.05) for their liking by a consumer panel even though they were all made the same way except for addition of color. The only difference in flavor detected by a trained panel was for a slight variation in bitterness. Using a combination of annatto and titanium dioxide produced a cheese that was rated the highest. Annatto when added singly produced a low-fat cheese that was rated the lowest. Moreover, commercial cheeses were also ranked significantly different for liking and buying preference.
For objective 3, several trials were conducted to enrich low-fat cheese with inulin, pectin, polydextrose, or resistant-starch either by incorporating them into cheesemilk, mixing with 15-d aged cheese followed by repressing, or by formulating a W/O/W emulsion with inulin and incorporating the emulsion into the milk prior to cheesemaking. Adding fibers directly to milk resulted in less or no retention of fibers in cheese, whereas fibers added to comminuted cheeses were too crumbly. Adding fiber as a W/O/W emulsion improved fiber retention in the cheese and produced an improved texture of low-fat cheese.
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Bulbul, Kanak. "Influence of Change in pH on Whey Expulsion from Cheddar Cheese Curds made from Recombined Concentrated Milk." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7440.
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The Western Dairy Center at Utah State University funded this project to investigate cheese research using concentrated milks. Concentrated milk was provided by the South Dakota State University and starter culture for this study was prepared and donated by Vivolac Cultures Corporation, Greenfield, Indiana.
The project initiated as a continuation of a previous study on effects of protein concentration, coagulum cut size and set temperature on curd moisture loss kinetics while stirring during cheesemaking. It was aimed at determining the extent to which pH drop prior to draining and final cheese moisture when using microfiltered concentrated milk.
We performed twelve cheesemaking trials using recombined milk from micellar casein concentrate, cream and skim milk according to a modified cheddar cheese-make procedure. Four different levels of starter cultures were used to achieve different acidification rates for pH change during cheesemaking. The amount of starter culture added had significant effect on moisture of cheese at whey drainage, moisture and pH of cheese. Thus, it can be said that the pH drop that occurs during the cheesemaking increases rate and extent of whey expulsion.
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Young, Michael J. "Characterization of Volatile and Metabolite Compounds Produced by Lactococcus lactis in Low-Fat and Full-Fat Cheddar Cheese Extract." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1029.
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This study was conducted to compare and contrast potential aroma compounds in the headspace and small molecule metabolites produced as a result of starter culture metabolism in a full-fat and low-fat cheddar cheese model system. Past studies have indicated differences in the headspace flavor compound profiles between full-fat and low-fat Cheddar cheeses with no indication as to what compounds were produced as a result of starter culture metabolism.
Starter cultures were incubated in a Cheddar cheese extract environment that was made up of the water-soluble portion of Cheddar cheese with environmental conditions mimicking full-fat and low-fat Cheddar cheese by altering the levels of salt and milk fat globular membrane in the system. Incubation times were up to 14 days at 30°C and samples were taken at days 0, 1, 7, and 14. Headspace analysis was accomplished using solid phase micro-extraction coupled with GC-MS and small metabolites were monitored using metabolomic methods coupled with GC-MS.
Results indicate that the starter culture was responsible for an increase in the concentration of propan-2-one, heptan-2-one, 3-methylbutanal, heptanal, benzaldehyde, 2-ethylhexanal, and dimethyl trisulfide in both the full-fat and low-fat medias when compared to their respective controls. While heptanal was present at a higher concentration in the full-fat treatments compared to the low-fat treatments and 2- ethylhexan-1-ol and isothiocyanato cyclohexane were present at higher concentrations in the low-fat treatments compared to the full-fat treatments.
Principal component analysis for the headspace compounds showed a clear separation of the treatments with heptanal, p-cymene, nonan-2-one, and undecan-2-one contributing the most to the variation between the full-fat and low-fat samples, while 3- methylbutanal, heptan-2-one, benzaldehyde, 2-ethylhexan-1-ol, 2,6-dimethylheptan-4-ol, and 3-methylbutanol contributed the most to the variation between the controls and treatments.
The metabolomics data for both the bacteria and Cheddar cheese extract did not provide a clear separation between the full-fat and low-fat samples.
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Suloff, Eric Charles. "Comparative Study of Semisynthetic Derivative of Natamycin and the Parent Antibiotic on the Spoilage of Shredded Cheddar Cheese." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/35937.
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The polyene macrolide antibiotic natamycin (Antibiotic A-5283) is commonly used to retard the growth of surface molds on various cheese varieties. Natamycin is commonly applied to the surface of cheese by dipping or spraying, using an aqueous dispersion containing 200 to 300 ppm of the additive. The large molecular weight of natamycin, 666 g/mol, and conjugated double bond structure causes it to be extremely insoluble in water and most food grade solvents. The inability to apply natamycin in true solution creates void non-treated areas on the food surface. These non-treated areas promote the growth of fungal organisms.
A water soluble N-alkyl semisynthetic derivative of natamycin was synthesized by the Michael addition reaction of the parent with a N-substituted malemide. A comparative study investigating the effectiveness of the semisynthetic derivative of natamycin and the parent antibiotic in suppressing mold growth on one month aged shredded Cheddar cheese modified atmosphere packaged (MAP) was performed. A 20 ppm natamycin treatment effectively suppressed visible mold growth (<104 CFU/g) in MAP samples for up to 30 days after opening. The 20 ppm semisynthetic derivative performed similarly to the 10 ppm natamycin treatment in retarding mold growth. Visible mold growth did not occur for these treatments in MAP samples until 20 days after opening. Analysis of storage conditions revealed that an outgrowth of mold in shredded cheese occurred in MAP packages stored longer than 15 days. This bloom in mold growth was attributed to the degradation of natamycin and the semisynthetic derivative throughout storage.
The stability and degradation of natamycin and the derivative were monitored throughout the study. Antibiotic concentration on the cheese surface was quantified by molecular absorption spectrometry. Results from this study showed, heavily contaminated samples caused the rate and loss of natamycin and the derivative to increase. Antibiotic concentration decreased at a similar rate in MAP and open package conditions. Natamycin and derivative were found to have similar degradation properties.Master of Science
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Singleton, Tyler J. "The Effect of Exopolysaccharide-producing Streptococcus thermophilus MR1C on Functionality in High Moisture Cheddar-type Cheese." DigitalCommons@USU, 2007. https://digitalcommons.usu.edu/etd/5537.
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Differences in texture at any particular stage of ripening depend upon differences in the basic structure and the extent to which the basic structure is modified by physical parameters. Thus, very young cheeses of the same variety differ in texture because of variations in pH and in salt, moisture, and fat content. How well a cheese melts and shreds depend on its texture and physical parameters. Streptococcus thermophilus MR1C produces an exopolysaccharide (EPS) that is tightly associated with the bacterial cell wall. Addition of S. thermophilus MR1C to the cheese make will increase the moisture of the cheese 2-3% and thus affect the texture, melt, and shreddability of that cheese.
To determine the effect of S. thermophilus MR1C on the texture, melt, and shreddability of cheese, two stirred-curd cheeses with equivalent physical parameters using BPS-producing S. thermophilus MR1C or non-BPS-producing S. thermophilus DM10 adjunct cultures were produced. Because MR1C cheese would increase moisture, the curd size, wash water temperature, and pH at salting had to be altered in order to make the physical parameters the same for both cheeses.
The MR1C cheese was harder and had a higher fracture stress than the DM10 cheese. The MRlC cheese was also more adhesive, but only for one of the two trials. Even with adjustments in the method of manufacture, the MR1C cheese still had a slightly higher SM and pH, which may be partly responsible for the differences between the two cheeses. There were no differences between the MRlC cheese and the DM1 0 cheese in shreddability as determined by fines, stickiness, and gumminess. Cheese produced without a streptoccus adjunct culture was more cohesive and had fewer fines than the MRIC or DM10 cheese.
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Shrestha, Subash. "Ensuring Microbial Safety in Food Product/Process Development: Alternative Processing of Meat Products and Pathogen Survival in Low-Salt Cheddar Cheese." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1163.
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Most outbreaks of foodborne illness in the United States occur as a result of improper food-handling and preparation practices in homes or food establishments. Some food-safety recommendations that are difficult to incorporate into handling and cooking procedures have contributed to a gap between food-safety knowledge and the actual behavior. The first part (Chapter 3, 4) of this study sought to ensure microbial safety by establishing alternative processing of meat products that can be easily practiced by food-operators and consumers. In Chapter 3, a novel method was developed to thaw frozen chicken-breast by submersion in hot water at 60 °C, an appropriate temperature setting for foodservice hot-holding equipment. This method is rapid (compared to either refrigerator or cold-water thawing that also uses a significant amount of water), safe, and the final cooked-product sensory-quality was not different from refrigerator-thawed and cooked product (microwave thawing results in localized overheating). Chapter 4 developed marinade-cooking (91 °C) and holding (60 °C) procedures for hamburger-patties. Frozen patties were partially grilled and finished cooking in marinade. The moderate temperature of marinade cooking overcomes the chances of thick-patties being surface-overcooked while innermost portions remain undercooked as seen in high-temperature cooking methods (grilling and pan-frying). Consumers liked the marinade-finished cooked and held patties (up to 4 h) equally or more (holding-time dependent) compared to patties grilled and held in a hot-steam cabinet.
Reducing salt in perishable foods including cheese is microbial-safety concern especially in their distribution and storage. The second part (Chapter 5, 6) of this study sought to evaluate microbial safety of low-salt hard-type cheese. Aged Cheddar cheeses were inoculated with either Listeria monocytogenes (3.5 log CFU/g) or Salmonella spp. (4.0 log CFU/g) and their survival or growth was monitored at 4, 10, and 21°C for up to 90, 90, and 30 d, respectively. Low-salt (0.7% NaCl) Cheddar formulated at pH 5.1 or 5.7 exhibited no-growth or gradual reduction in L. monocytogenes and Salmonella counts. The results suggest that low-salt Cheddar is as safe as its full-salt counterparts (1.8% NaCl) and that salt may only be a minor food-safety hurdle regarding the post-aging contamination and growth of L. monocytogenes and Salmonella.
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Venter, P., T. Venter, N. Luwes, Smidt O. De, and J. F. R. Lues. "Towards the discrimination of milk (origin) applied in cheddar cheese manufacturing through the application of an artificial neural network approach on Lactococcus lactis profiles." Journal for New Generation Sciences, Vol 11, Issue 1: Central University of Technology, Free State, Bloemfontein, 2013. http://hdl.handle.net/11462/632.
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Published ArticleAn artificial neural network (ANN) that is able to distinguish between Cheddar cheese produced with milk from mixed and single breed sources was designed. Samples of each batch (4 pure Ayrshire/4 mixed with no Ayrshire milk) were ripened for 92 days and analysed every 14 days. A novel ANN was designed and applied which, based only on Lactococcus lactis counts, provided an acceptable classification of the cheeses. The ANN consisted of a multi-layered network with supervised training arranged in an ordered hierarchy of layers, in which connections were allowed only between nodes in immediately adjacent layers.
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Rasmussen, Taylor. "Texture Profile Analysis and Melting in Relation to Proteolysis as Influenced by Aging Temperature and Cultures in Cheddar Cheese." DigitalCommons@USU, 2007. https://digitalcommons.usu.edu/etd/5543.
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Changes in cheese physical properties during aging are related to proteolysis by coagulant type, culture enzymes, and non-starter lactic acid bacteria (NSLAB). Storage temperature also affects aging rate. Cultures are important for flavor development , but less is understood about their role in melting and textural properties.
Our objective was to make Cheddar cheese using different cultures, to age it at 6 and 13°C, and measure physical and proteolytic properties over 12 mo to determine whether changes in texture and melting correlated with the extent of proteolysis that occurred during aging.
Cheese was manufactured using Lactococcus lactis starter culture either alone or combined with one or both of Lac Lc. Lactis or Lactobacillus helveticus adjunct cultures . Three replicates of cheese were made using 1500 lb of milk. Cheese composition was 35.5 ± 1.0% moisture, 52.5 ± 2.5% FDB, 1.65 ± 0.05% salt, and pH 5.2 ± 0.1. All cheeses were initially stored at 6°C, then half moved to l3°C after 21 d.
Texture profile analysis was performed using 25% and 60% compression and melting measured using a Meltmeter at 65°C. The data were analyzed based on culture and temperature over 12-mo storage time. The overall hardness decreased, while the cohesiveness decreased for all treatments. Extent of melting was significantly correlated with hardness (r = 0.62), cohesiveness (r = 0.40), and inversely with adhesiveness (r = 0.24). Correlations with adhesiveness and cohesiveness were not linear.
Proteins were extracted from cheese at 1 wk, 1, 2, 4, 6, 9, and 12 mo of aging using 500 mM sodium citrate solution containing 1% sodium chloride. Purified extracts were then applied to a high-performance liquid chromatography CS reverse phase column and large hydrophobic peptides and protein peaks monitored at 214 nm. Melting was inversely correlated with the amount of intact ɑs1-caserienm remaining in the cheese (r = -0.54) and directly correlated with what was thought to be ɑs1-casein (f 24 - 199) (r = 0.56).
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Chen, Manxiang. "Study of Ripening Characteristics of Full-Fat and Low-Fat Cheddar Cheese Using Fourier Transform Infrared Spectroscopy and Texture Analyzer." DigitalCommons@USU, 1998. https://digitalcommons.usu.edu/etd/5448.
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A suitable microtome sampling technique was used to sample cheese for analysis using FTIR spectroscopy. Well-separated fat- and protein-related bands were obtained in the spectra of Cheddar and Mozzarella cheese samples using this method. The absorbance intensity of the spectra was proportional to the thickness of the sample. The intensity of absorbance and fat- and protein-related bands increased with an increase in the fat and protein content in the sample. Strong and well-separated bands at 1744, 1450, 1240, 1170, and 1115 cm-1 arising mainly from fat content were observed using this method. Bands observed at 1650 and 1540 cm-1 were attributed to the protein present in the cheese. Bands at 1615-1639, 1640-1648, 1650-1658, and 1660-1688 cm-1 corresponding to β-sheet, random coil, helix, and the turns/sheet portion of the secondary structure were observed int he range of the amide I band.
Characteristics of spectra for full-fat (FFCC) and reduced-fat Cheddar cheese (RFCC) during ripening were investigated. The absorbance of bands at 1116-1240 from C-C, C-O, C-N stretch, 1461 cm-1 from C-N bend (scissoring), 1744 cm-1 from ester carbonyl groups (fat A), 2850-2930 cm-1 from C-H stretch (fat B), 1650 and 1540 cm-1 from protein amide I and II varied druing cheese aging. Bands at 1116 and1240 cm-1 arising from C-O, C-N, and C-C stretch changed slightly during cheese aging. A correlation coefficient of 0.97 for bands between 1744 and 1167 cm-1 arising from fat, and that of 0.93 at 1650 and 1540 cm-1 arising from protein, respectively, showed that one of these fat or protein groups was highly related to the other. A correlation coefficient of greater than 0.80 among the bands of fat and protein groups indicated a strong interaction in those bands. Correlation of ripening time and absorbance at bands corresponding to each function group was analyzed. A ripening index model was obtained by correlating ripening time with predominant reactive group absorbance peaks. An R2 of 0.83 and 0.59 was obtained for full-fat and reduced fat Cheddar cheese, respectively.
Texture development and its correlation with FTIR spectra data for FFCC and RFCC during aging were also studied. RFCC had a higher value of hardness, gumminess, and chewiness than its full-fat counterpart. The values decreased during the early stages of ripening and then increased with time. The change in hardness, adhesiveness, and springiness was expressed as a function of the change in absorbance of the FTIR spectra using multiple regression analysis. An R2 value of 0.67, 0.54, and 0.75 was obtained for full-fat Cheddar cheese, and a value of 0.51, 0.59, and 0.54 was obtained for reduced-fat Cheddar cheese for the respective texture parameters.
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Roberts, Alison K'Ann. "The Effect of Sorbic Acid on the Survival oOf Escherichia coli 0157:H7, Salmonella, Listeria monocytogenes, and Staphylococcus aureus on Shredded Cheddar and Mozzarella Cheese." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/31440.
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The objective of this study was to determine the effectiveness of sorbic acid in inhibiting Escherichia coli 0157:H7, Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus on shredded cheddar and mozzarella cheese over 70 days storage. Samples of cheese were inoculated and placed into bags with a sorbic acid (0, 0.1, 0.15, 0.2 and 0.3 %) and anti caking agent mixture and stored at 10â aC. Each variable was enumerated after 0,14,28,42,56, and 70 days of storage. Survival of E. coli 0157:H7 showed no significant difference from control in either cheese. There were significantly lower Salmonella counts for days 14 to 42 on mozzarella cheese. No significant differences in survival were found for cheddar cheese. There were significantly lower counts noted in L. monocytogenes, and S. aureus in mozzarella. Though no significant differences were found over time in the cheddar, most of the sorbate concentrations exhibited lower counts than control on days 14 and 28. Overall, in the presence of sorbic acid there was a more rapid decline in numbers of each test organism, especially against L. monocytogenes, and S. aureus for both high and low moisture cheeses.Master of Science
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Ummadi, Madhavi. "Tryptophan Catabolism in Brevibacterium linens BL2." DigitalCommons@USU, 2002. https://digitalcommons.usu.edu/etd/5501.
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Recent studies suggest aromatic amino acid catabolism by starter lactococci and flavor adjunct bacteria have a significant impact on off-flavor development during Cheddar cheese ripening. We hypothesized that a flavor adjunct bacterium, Brevibacterium linens BL2, produces off-flavor compounds from aromatic amino acid metabolism that will have a detrimental impact on cheese flavor.
The mechanism of tryptophan (Trp) catabolism in Brevibacterium linens BL2, was investigated in a chemically defined medium during incubation in laboratory conditions (no carbohydrate, pH 6.50, 220 rpm, 25°C) and cheese-like conditions (no carbohydrate, 4% NaCl, static incubation, l5°C). In laboratory conditions, metabolic studies and enzyme assays confirmed that Trp was converted to kynurenine and anthranilic acid. However, cells incubated in cheese-like conditions did not utilize Trp, indicating that these enzymes are not likely to be involved in formation of Trp compounds associated with off-flavors in Cheddar cheese.
In an attempt to verify the metabolic activity of the cells during incubation by monitoring the amino acid metabolism in chemically defined medium inoculated with B. linens BL2, a capillary electrophoresis-laser-induced fluorescence method was developed that could separate, detect, and quantitate 18 amino acids within 38 min. The data indicated that B. linens BL2 was metabolically active. Presumably, the cells will be metabolically active and metabolize amino acids in cheese as well.
The ability to determine the Trp metabolic activity of B. linens BL2 in cheese, and to quantify Trp catabolic compounds in cheese during ripening, requires a quantitative extraction procedure. An analytical method was developed to extract and quantify aromatic amino acids and Trp catabolites from cheese using capillary electrophoresis. Methanol was used to extract Cheddar cheese made with Lactococcus lactis S3 alone and in combination with B. linens BL2 to quantitatively determine the influence of BL2 on the occurrence of aromatic catabolites. All cheeses contained aromatic amino acids, indole acetic acid, and indole. The concentration and time taken for development of these compounds were significantly decreased or delayed by the addition of B. linens BL2. After 6 months of aging, the concentrations of Trp catabolites were significantly lower in cheese made with B. linens BL2. Addition of BL2 did not directly contribute to off-flavors derived from Trp catabolism in Cheddar cheese. Therefore, the hypothesis was rejected.
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Ayala-Bribiesca, Erik. "Effect of calcium on bioaccessibility of milk fat during digestion of Cheddar-type cheeses." Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/28167.
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Le fromage cheddar est reconnu comme une excellente source de calcium. Outre son intérêt nutritionnel intrinsèque, le calcium favorise la lipolyse lors de la digestion. Cet effet s’explique par la formation de savons de calcium avec les acides gras saturés à longue chaîne, ce qui entraîne l’exposition de nouveau substrat à l’interphase huile-eau des gouttelettes de gras laitier, permettant à la lipase de continuer son action. En contrepartie, les savons de calcium limitent l'absorption des acides gras impliqués. D’un point de vue technologique, le calcium joue un rôle clé dans la structure du fromage car il participe à la formation du gel de paracaséine. Ayant un effet sur la matrice fromagère et sur la digestion des lipides, le calcium peut alors modifier la biodisponibilité du gras laitier. L’objectif de ce projet était de mieux comprendre l’effet du calcium sur la biodisponibilité du gras laitier à partir de fromages de type cheddar avec le but éventuel de développer des aliments pouvant contrôler la digestion et l’absorption des lipides. Dans un premier temps, des fromages de type cheddar enrichis en calcium par l’ajout de CaCl₂ ont été soumis à une digestion in vitro. L’analyse des chymes a permis de démontrer que les fromages enrichis se désintégraient plus lentement que leur contrôle sans calcium ajouté. D’une autre part, la libération d’acides gras des fromages enrichis progressait plus rapidement, mettant en évidence l’effet du calcium sur les mécanismes impliqués dans la lipolyse. Dans un second temps, des fromages de type cheddar ont été fabriqués à partir de lait standardisé avec des huiles de beurre contrôle, oléine et stéarine et salés avec ou sans CaCl₂. Les fromages ont été digérés in vitro pour étudier l’effet du calcium sur la lipolyse et la formation de savons de calcium avec les huiles de beurre ayant différents profils d’acides gras. Les fromages préparés avec la fraction stéarine (avec le rapport le plus élevé d’acides gras saturés à longue chaîne) étaient plus résistants à la désintégration physique et présentaient une lipolyse plus lente que les autres fromages, en raison du point de fusion élevé de cette matière grasse. Les fromages enrichis en calcium présentaient des taux de lipolyse supérieurs aux fromages sans enrichissement. Cette lipolyse accrue a été expliquée par la formation de savons de calcium avec des acides gras à longue chaîne. Ces composés insolubles pourraient toutefois réduire la biodisponibilité des acides gras impliqués en empêchant leur absorption. Pour confirmer l’effet du calcium et du type de matière grasse sur la biodisponibilité des lipides, les fromages ont été utilisés par la suite pour une étude chez le rat. La lipémie postprandiale des animaux a été mesurée suite à l’ingestion du fromage. Les matières fécales ont été analysées pour quantifier les acides gras excrétés sous forme de savons de calcium. Les fromages ont eu des effets différents au niveau de la lipémie postprandiale. L'enrichissement en calcium a entraîné une augmentation de la lipémie avec les fromages à l'oléine, alors qu'un pic différé a été observé avec les fromages à stéarine. Ceci s'explique par la formation de savons de calcium avec des acides gras saturés à longue chaîne, favorisant indirectement une lipolyse plus rapide de ceux à courtes et à moyennes chaînes. Le retard du pic pour les fromages à base de stéarine s’expliquait par leur teneur plus élevée en acides gras saturés à longue chaîne, qui formaient des savons avec le calcium et se retrouvaient dans les fèces. Les résultats confirment que le calcium affecte la digestion intestinale des lipides laitiers en augmentant le taux de lipolyse. Cependant, il limite également la bioaccessibilité des acides gras en produisant, au pH intestinal, des savons de calcium insolubles avec des acides gras saturés à longue chaîne. Ce projet démontre que la biodisponibilité des lipides peut être régulée par le calcium présent dans le fromage cheddar. Cette étude met en évidence l'interaction en cours de digestion du calcium et des lipides présents dans la matrice laitière et confirme sa répercussion physiologique. Ces effets sur la digestion et l'absorption des lipides sont d’intérêt pour la conception de matrices alimentaires pour la libération contrôlée de nutriments et bioactifs liposolubles. D'autres recherches dans ce domaine permettront de mieux comprendre le rôle joué par les aliments sur la santé humaine et d’habiliter le développement de produits laitiers pour contrôler la libération de nutriments afin de moduler les réponses métaboliques. Mots clés : fromage, gras laitier, digestion, lipolyse, savons de calcium.Cheddar cheese is recognized as an excellent source of calcium. In addition to its intrinsic nutritional value, calcium promotes lipolysis during digestion. This lipolysis enhancing effect is explained by the formation of calcium soaps with saturated long-chain fatty acids, resulting in the exposure of new substrate to the oil-water interphase of the milk fat droplets, thus enabling lipase to continue its action. On the other hand, the formation of calcium soaps reduces the absorption of saturated long-chain fatty acids. From a technological point of view, calcium plays a key role in the cheese structure as it participates in the formation of the paracasein gel. By such effects on the cheese matrix and the digestion of lipids, calcium can modify the bioavailability of the dairy fat. The objective of this project was to better understand the effect of calcium on the bioavailability of dairy fat from Cheddar cheeses, in aim to developing food matrices for controlled digestion and absorption of lipids. In a first step, Cheddar cheeses enriched with calcium by the addition of CaCl₂ were subjected to digestion in vitro. Chyme analysis showed that calcium-enriched cheeses disintegrated less rapidly than the non-enriched control but that their lipolysis progressed more rapidly, demonstrating the effect of calcium on the factors that influence lipolysis. In a second step, Cheddar cheeses were made from standardized milk with control, olein and stearin butter oils and salted with or without CaCl₂. The cheeses were digested in vitro to study the effect of calcium on lipolysis and the formation of calcium soaps from butter oils with different fatty acid profiles. Cheeses prepared with the stearin fraction (with the highest ratio of saturated long-chain fatty acids) were more resistant to physical disintegration and presented slower lipolysis than the other cheeses because of the high melting point of this fat. Cheeses enriched with calcium had higher levels of lipolysis than cheeses without enrichment. This increased lipolysis was due to the formation of calcium soaps with saturated long-chain fatty acids. These insoluble compounds could reduce the bioavailability of the fatty acids involved by preventing their absorption. To confirm the effect of calcium and type of fat on lipid bioavailability, the cheeses were subsequently used for an in vivo study. Postprandial lipemia of Wistar rats was monitored following ingestion of the cheese. The feces were analyzed to quantify the fatty acids excreted as calcium soaps. The cheeses had different effects in postprandial lipemia. Calcium enrichment led to a higher lipemic peak for the cheeses with olein, while a delayed peak was observed for cheeses with the stearin. This was explained by the increased affinity of calcium for saturated long-chain fatty acids, indirectly allowing faster lipolysis of other fatty acids, such as those with short- and medium-chains. The delay for stearin cheeses was due to their high content of saturated long-chain fatty acids, which formed soaps with calcium, thus reducing their absorption and ending up in feces. The results confirm that calcium plays an important role in intestinal digestion of dairy lipids by increasing the rate of lipolysis. However, it also limits the bioaccessibility of fatty acids by producing insoluble calcium soaps with saturated long-chain fatty acids at intestinal pH conditions. This project demonstrates that the bioavailability of lipids can be regulated by calcium in Cheddar cheese. This study demonstrates the interaction of calcium and lipids present in the dairy matrix during digestion and confirms its physiological repercussion. These effects on digestion and lipid absorption are of interest for the design of food matrices for the controlled release of liposoluble nutrients or bioactive molecules. Further research in this area will provide a better understanding of the role of foods in human health and enable the development of dairy products to control the release of nutrients to modulate metabolic responses. Keywords: Cheese, milk fat, digestion, lipolysis, calcium soaps.
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Solecki, Sarah Goler. "A tale of two cheeses : Parmesan, Cheddar, and the politics of Generic Geographical Indications (GGIs)." Thesis, University of Warwick, 2014. http://wrap.warwick.ac.uk/69132/.
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The difference between Geographical Indication (GI) and generic food terms is an important and highly contentious issue in international negotiations. This distinction is of significant importance to producers, manufacturers, consumers, and policy-makers all over the world because it means the difference between the restricted versus open use of certain popular terms in domestic and global markets. This thesis uses a food studies approach that employs cheese as a lens to understand the contested politics of Generic Geographical Indications (GGIs), which has been under-explored in the literature on GIs. Through case study and an analysis of written policy material and other documents, websites, blogs, artifacts, observations, and semi-structured interviews and discussions, it investigates the complex processes through which European and New World (NW) actors compete over the status – protected or generic - of cheese names, why this struggle is manifested in the case of Parmesan but not of Cheddar, and how we can better understand genericism within the context of GI policy. The thesis argues that actors guided by differing agricultural paradigms compete to secure the use of terms through oppositional discursive strategies of ‘gastro-panic’ where they appeal to a language of security in order to persuade policy-makers to take action against the perceived threatening actions of their opponents. It finds that unlike the contested term Parmesan no such panic has emerged surrounding Cheddar because its widespread use has not been interpreted as a threat to the ‘original.’ As well, genericism emerges as both a dynamic and socially-constructed concept subject to ongoing negotiation and contestation and a strategic discursive device used block the successful registration of proposed product names as GIs. The debate over cheese reveals the inherently political nature of the ways in which genuineness and genericness are constructed in an increasingly competitive marketplace.
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Chen, Hong-Chih, and 陳鴻志. "Manufacture of Goat Cheddar-type Cheese." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/45115639041022757229.
Full textAbstract:
碩士國立屏東科技大學
畜產系
94
The purpose of this study was to develop a type of goat Cheddar-type cheese for the local market. Goat Cheddar-type cheeses were fermented with 1％, 2％ and 4％ Lactobacillus casei subsp. casei BCRC12272 (Lc) and Lactococcus lactis subsp. lactis BCRC14105 (Ll) (1:1), 2% Streptococcus thermophilus BCRC14086 (St) and Lactobacillus delbrueckii subsp. bulgaricus BCRC14009 (Lb) (1:1), respectively. All cheeses were vacuum packed and ripened at 4℃ for 60 days. The physicochemical properties and sensory evaluation of cheeses were measured every 15 day. The gross compositions (water, crude fat and protein), pH value, titratable acidity (TA), total bacterial count (TBC), lactic acid bacteria (LAB) count, non-starter lactic acid bacteria (NSLAB) count, free fatty acid (FFA), hydrolyzed amino acid (AA) analysis and sensory evaluation were measured. The type and amount of starter cultures did not affect the water and fat contents of cheese significantly. Moreover, the water, fat and protein contents of cheeses of all treatments were not affected by the ripening time. The pH value of cheeses decreased and the TA increased gradually during ripening. The changes of pH and TA were dramatic during the 1-15 day period (P<0.05). In addition, the TBC, LAB and NSLAB at day 1 of ripening was at the similar concentration of 108-109 CFU/g. During day 1-15 of ripening, the TBC, LAB and NSLAB of all cheeses increased significantly (P<0.05). The percentages of C4：0, C6：0, C8：0, C10：0 and C12：0 fatty acids of all cheeses increased during the 1-30 day period, but C18:1 and C18:2 decreased. Glu, Pro, Leu, Val and Lys amino acid were the major amino acids of all cheeses. The amounts of these amino acids were not changed significantly during ripening (P>0.05). Result of sensory evaluation showed that 2％ Lc/Ll goat Cheddar-type cheese had the best overall acceptability of all cheeses. The measurements of 2％ Lc/Ll goat Cheddar-type cheese with 30-day ripening were moisture 49.87％, pH 4.65, TA 1.90％, TBC 11.03 Log CFU/g, LAB 10.70 Log CFU/g, C6：0 fatty acid 28.23 mg/mL, C10：0 fatty acid 165.57 mg/mL, Glutamic acid 4259.65/100 g cheeses, Lysine 1283.43 mg/100 g cheeses, respectively. In conclusion, goat Cheddar-type cheese which was made from goat milk by pasteurizing, adding 2％ Lc/Ll and rennet, cutting, cooking, stirring, salting, moulding, pressing and ripening at 4℃for 30 days had the best eating quality.
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Marschoun, Laurentia T. "Thermal and dielectric properties of cheddar cheese." 1998. http://catalog.hathitrust.org/api/volumes/oclc/41830083.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1998.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 179-182).
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Oyugi, Evonne Laura Adhiambo. "Microbiological quality of shredded Cheddar cheese packaged in modified atmospheres." Diss., 2004. http://hdl.handle.net/2263/23089.
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Kau, Reginah Nki. "Pediococci in South African Cheddar and Gouda cheese." Diss., 2003. http://hdl.handle.net/2263/26935.
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Liao, Pei-Ru, and 廖珮如. "Manufacture of Cheddar-type Cheese and Fermented Whey." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/46852111056293169959.
Full textAbstract:
碩士國立屏東科技大學
畜產系
94
Cheese is rich in the protein , calcium and vitamins. Most cheeses in Taiwan were imported from other countries. The consumption of cheeses increased gradually in recent years. However, the price and taste were not fully accepted locally. The purpose of this study was to develop a type of Cheddar-type cheese for the local market. Cheddar-type cheeses were inoculated with 1, 2and 4% Lactobacillus casei subsp. casei BCRC12272 (Lc) and Lactococcus lactis subsp. lactis BCRC14105 (Ll) (1:1), 2% Streptococcus thermophilus BCRC14086 (St) and Lb. delbrueckii subsp. bulgaricus BCRC14009 (Lb) (1:1), respectively. All cheeses were vacuum packed and ripened at 4℃ for 90 days. The cheeses physicochemical properties and sensory evaluation were measured every 15 day. Results showed that moisture, fat and protein content of the cheeses were 42-53%, 20-32% and 16-23%, respectively. The pH of cheeses decreased and titratable acidity (TA) increased during ripening. The C4 fatty acid (FA) contents of all cheeses increased during ripening. 4% Lc/Ll cheese had the highest C4 FA content. The percentages of C16、C18:0 and C18:2 FA of all cheeses increased during ripening, but C8, C10, C12, C14 and C18:1 decreased. Results of sensory evaluation showed that 4% Lc/Ll Cheddar-type cheese had the best sweet, elastic and acceptability of all cheeses at 60 days of ripening. The moisture, fat and protein content of 4% Lc/Ll Cheddar-type cheese were 46.22%, 27.50% and 18.71%, respectively. The pH and TA of 4% Lc/Ll Cheddar-type cheese were 5.38 and 0.24%. Total bacterial counts, lactic acid bacterial counts and non-starter lactic acid bacterial counts of 4% Lc/Ll Cheddar-type cheese were over 107-108 CFU/g, and the C4 FA content was 0.54 μL/g. Whey is the major (80-90%) by-product of cheese manufacturing. The purpose of this study was to investigate a suitable manufacturing condition for cheese whey products for the local market. Whey collected from the production of Lb. casei (Lc) and Lactococcus lactis (Ll) (1:1) cheese was added with 5, 10, 15 and 20% sucrose. Whey collected from the production of 2% Streptococcus thermophilus (St) and Lb. bulgaricus (Lb) (1:1) cheese was added with 20% sucrose (control). All whey solutions was manufactured with 2% Saccharomyces bayanus and Sacchar. cerevisiae (1:1), fermented at 20℃ for 20 days. The pH, titratable acidity (TA), total degree of sugar, total bacterial counts, lactic acid bacterial counts, yeast counts, ethanol concentration and sensory evaluation of the fermented whey were measured. Results showed that fat, protein, lactose and solid contents of the fermented whey were 2-5%, 2-4%, 10-22% and 13-27%, respectively. The pH of fermented whey decreased and TA increased during fermentation. Total yeast counts of fermented whey decreased during fermentation. Ethanol concentration of fermented whey was increased at 16 days of fermentation, while the control group had the highest ethanol concentration (P＜0.05). The sensory evaluation showed that the 15% sucrose Lc/Ll fermented whey had the best creamy, sweet, aftertaste and acceptability at 16 days of fermentation of all fermented whey. The pH and TA of the 15% sucrose Lc/Ll fermented whey were 3.4 and 10.50%, respectively. The total degree of sugar and ethanol concentration of the 15% sucrose Lc/Ll fermented whey were 18.00 °Brix and 0.43%, respectively.
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Lemus, Freddy Mauricio. "Flavor development of cheddar cheese under different manufacturing practices." Thesis, 2012. http://hdl.handle.net/1957/35594.
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Cheddar Cheese samples (good cheese, weak cheese, cheese made with pasteurized milk, cheese made with heat-shocked milk, cheese from production plant A, cheese from production plant B, cheese made with adjunct culture, and cheese made without adjunct culture), were evaluated during the ripening stage. Proteolysis was studied by a fractionation scheme, resulting in an insoluble fraction analyzed by urea polyacrylamide gel electrophoresis (Urea-PAGE), and a soluble fraction which was further investigated through water soluble nitrogen (WSN), trichloroacetic acid soluble nitrogen (TCA-SN) and phosphotungstic acid soluble nitrogen (PTA-SN) analyzed by total Kjeldahl nitrogen content (TKN). Reversed phase high performance liquid chromatography (RP-HPLC) was used to study the peptide profile of the water soluble fraction. Lipolyisis was studied by levels of individual free fatty acids determined through gas chromatography-flame ionization detection (GC-FID) after isolation employing solid phase extraction (SPE). Volatile sulfur compounds were studied using head space solid phase micro-extraction (SPME) coupled with gas chromatography-pulsed flame photometric detection (PFPD).
It was found that Urea-PAGE is capable to differentiate samples according their age, but cannot discriminate samples regarding the treatment assessed, quality or origin of the samples. However, measurements of total Kjeldahl Nitrogen (TKN) of the WSN, TCA-SN, and PTA-SN fractions, and the principal component analysis of the RP-HPLC peptide profile of the WSN fraction, revealed differences in the rate and pattern of proteolysis for each one of the manufacturing cases. Good cheese, cheese produce in plant TCCA, cheese made in plant CRP with adjunct culture isolated from plant TCCA cheese, and cheese made with heat-shocked milk developed higher level of total nitrogen for the WSN, TCA-SN and PTA-SN fractions, indicating that primary and secondary proteolysis were faster for these samples. This is supported by a PCA model with three principal components that account for the 80-83% of the variability of the data from the RP-HPLC peptide profile analysis, which discriminates the samples according to age and manufacturing practice. In addition, FFA profiles demonstrated higher levels of low and medium chain free fatty acids for good cheese, cheese produce in plant TCCA, cheese made in plant CRP with adjunct culture, and cheese made with heat-shocked milk samples, which suggest faster lipolysis during ripening. The Volatile Sulfur Compounds (VSC) analysis showed higher levels of DMS and MeSH and lower levels of H2S, suggesting faster catabolism of sulfur containing amino acids in good cheese, cheese produce in plant TCCA, cheese made in plant CRP with adjunct culture, and cheese made with heat-shocked milk.Graduation date: 2013
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Kilic̦, Meral. "Nonenzymatic browning and storage stability of cheddar Cheese powder." 1995. http://catalog.hathitrust.org/api/volumes/oclc/34542724.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1995.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 91-101).
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Yang, Jie. "Evaluation of hydrostatic pressure and storage effects on Cheddar cheese microstructure by thermal conductivity, differential scanning calorimetry and enzymatic proteolysis." Thesis, 1999. http://hdl.handle.net/1957/26048.
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