Dissertations / Theses: 'Oils and fats, Edible Oxidation'

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Aladedunye, Adekunle Felix. "Inhibiting thermo-oxidative degradation of oils during frying." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Chemistry and Biochemistry, 2011, 2011. http://hdl.handle.net/10133/3257.

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The present study sought for practical ways to improve the frying performance of oils without compromising the availability of the essential fatty acids and nutraceuticals. To this end, the influence of temperature, oxygen concentrations, and compositions of minor components on frying performance was investigated. A novel frying protocol, utilizing carbon dioxide blanketing, was developed and found to significantly improve the performance of the frying oil. Optimizing both the amounts and the compositions of endogenous minor components also improved the performance of the frying oil. Twenty one novel antioxidants were synthesized and evaluated under frying and storage conditions. Antioxidant formulations consisting of a combination of endogenous and synthesized antioxidants were developed and tested in an institutional frying operation. A rapid and effective frying test was developed to assess the frying performance of oils and applied antioxidants. Furthermore, a novel procedure for direct hydroxynonenal analysis in frying oil was developed.
xx, 249 leaves; 29 cm

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Cash, Gregory Anthony. "Studies of the oxidation and stabilisation of vegetable oils and model compounds." Thesis, Queensland University of Technology, 1986. https://eprints.qut.edu.au/35985/1/35985_Cash_1986.pdf.

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This thesis describes the use of a novel chemiluminescence (CL) technique to deter·mine the extent of oxidation and stability in both model compounds and vegetable oils. As it is the presence of hydroperoxides in vegetable oils that leads to theirdeterioration, the hydroperoxides of methyl linoleate (MU were used as model compounds in a CL study of hydroperoxide decomposition in nitrogen, both in the bulk and on active substrates. The largest signals and the fastest decays occurred on neutral alumina. The results indicate induced decomposition via a bimolecular initiation of hydroperoxides adsorbed on adjacent active sites. The majority of these hydroperoxides are vertical to the surface, being bound to the alumina through the ester group only. A relationship was found between hydroperoxide concentr·ation and initial intensity when the methyl linoleate hydroperoxide was adsorbed on neutral alumina. Solutions of natural and arti-ficial antioxidants in ML were studied. Some solutions gave changes in kinetics. These changes suggest that the antioxidant itself may contribute to the CL. The method of inhibitors was used to find the rate of initiation and hydroperoxide level in ML at 80c:>C. The spectral distribution of CL was determined for model compounds, antioxidants and vegetable oils. In the presence of antioxidants ther-e was a shift towar-d the r-ed end of the spectr-um. In model compounds, the CL was most likely due to an excited triplet state ketone and this is consistent with the mechanism for- ter·mination of alkyl peroxy r-adicals. The techniques developed for the model compounds were extended to the mor-e complex vegetable oils. Unrefined and deliberately damaged vegetable oils were studied at 80c:>C on neutral alumina. CL examination of these oils in nitr-ogen was able to distinguish between some damaged and undamaged oils. Conjugated diene levels did not correlate well with CL results. 0<-tocopherol and a-carotene were found to be chemiluminescent on alumina and their presence in unr·efined oil may inter·fer·e with CL assessment. The method of inhibitors, when applied to a vegetable oil sample, permitted the determination of both hydroperoxide concentration and the level of natural antioxidant alr-eady present in the oil. ii

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Russin, Ted Anthony. "A novel and rapid method to monitor the autoxidation of edible oils using Fourier transform infrared spectroscopy and disposable infrared cards /." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79119.

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A novel and rapid method was developed to monitor the autoxidation of edible oils by Fourier transform infrared (FTIR) spectroscopy with the use of disposable polymer infrared (PIR) cards having a microporous polytetrafluoroethylene (PTFE) sample substrate. Under conditions of mild heating (~58°C) and aeration, both model triacylglycerols (TAGS) and edible oils applied onto the PIR cards underwent rapidly accelerated oxidation. In order to compare the oxidative stability of samples on the PIR cards in terms of the time required to reach a peroxide value (PV) of 100 mequiv/kg oil, matching the end-point measured in the standard active oxygen method (AOM), an absorbance slope factor (ASF) was determined to relate changes in hydroperoxide (ROOH) absorbance (peak maximum found within the range of 3500--3200 cm-1 ) to PV. Similar ASF values were found for the four edible oils tested (safflower, canola, sunflower, and extra virgin olive oil), permitting determination of a pooled, universally applicable ASF value of 0.0526 mAbs/PV.

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Bati, Nabil A. "Thermal, oxidative and hydrolytic stability of selected frying shortenings evaluated by new and conventional methods." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54488.

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The thermal, oxidative, and hydrolytic stability of several frying shortenings were studied via chemical, physical and sensory analyses. Corn, cottonseed and peanut oils, and cottonseed and soybean liquid shortenings were tested under static heating conditions, while peanut oil, and cottonseed and soybean oil liquid shortenings were evaluated under commercial frying conditions. The research had two objectives: to evaluate the relative stability of the various shortenings under both heating condition; and to evaluate new or modified quality assessment methods which would provide early prediction of heat abuse for the fast-food industry. Six of the conducted analyses were conventional or modified: free fatty acids; polar components; gas chromatograph volatile profiles; viscosity; FoodOil-Sensor; and sensory. Three were new: contact angle; high temperature; and high-temperature gas chromatographic analysis of triglyceride; and polar component % as determined by high-performance thin-layer chromatography (HPTLC). Under static heating conditions, varying heating periods or shortening types had significant (P<0.000l) effects on the resulting data of the following tests: free fatty acids; polar component; total volatiles; dielectric constant; viscosity; polar component % measured by HPTLC; contact angle; and sensory analysis; but heating time had no significant effect on triglyceride profiles Under commercial frying conditions of chicken nuggets and filets, heating time had significant effects on changes in the dielectric constant; free fatty acid %; viscosity; contact angle; and sensory rating; also it had a significant effect on the polar component % under chicken nugget frying conditions only. Furthermore, heating time had no significant effect on polar component % under chicken filet frying conditions and on polar component % by HPTLC under both frying conditions Cottonseed oil liquid shortening had sensory scores equal to peanut oil under static and commercial frying conditions even though peanut oil exhibited a greater chemical and physical stability. Soybean oil liquid shortening had an objective quality identical to peanut oil, however, its subjective quality was lower. Cottonseed oil liquid shortening had better flavor but less objective stability than soybean oil liquid shortening The cut-off quality level for the shortenings was not reached, because all the shortenings were discarded after seven days of use which was before the onset of significant-quality deterioration. The best on-site index of shortening stability was the FoodOil-Sensor reading (dielectric constant) which was followed by the free fatty acid test.
Ph. D.

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Dubois, Janie. "Determination of peroxide value and anisidine value using Fourier transform infrared spectroscopy." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23391.

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Lipid oxidation has important consequences in the edible oil industry, producing compounds with sensory impact and thus reducing the economic value of the products. This work focused on the development of two Fourier transform infrared (FTIR) spectroscopy methods for the measurement of peroxide value (PV) and anisidine value (AV), representing the primary and secondary oxidation products of edible oils.
The infrared method developed for PV determination was based on a mathematical treatment by the partial least squares method of the information contained in the spectral region between 3750 and 3150 cm$ sp{-1}$.
The second method developed considered aldehyde content and anisidine value, a measure of secondary oxidation products.
The two methods developed are rapid ($ sim$2 min/sample) and have the advantage of being automatable. An infrared system coupled to a computer can collect the spectrum of an oil, analyze it and present a report without the need for personnel trained in FTIR spectroscopy. The cost of such a system would rapidly be absorbed through savings on personnel cost, time and chemical reagents required for conventional chemical methods and as such provides a useful advance in quality control methodology for the edible oils sector. (Abstract shortened by UMI.)

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Schoeman, Mathilda Elizabeth. "Mango (Mangifera indica L.) kernel fat : fatty acid profile, oxidative stability and development of fourier transform near infrared (FT-NIR) spectroscopy calibration models." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52925.

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Thesis (MSc Food Sc )--Stellenbosch University, 2002.
ENGLISH ABSTRACT: The oxidative stability of crude, cold-pressed mango kernel fat (MKF) was determined over a period of 240 days using the peroxide value (PV), conjugated diene value (CD) and p-anisidine value (AV) tests. The changes in fatty acid profile were monitored with gas chromatography and the oxidative status of MKF effectively predicted by FT-NIR spectroscopy. Results obtained from the different methods complemented each other and indicated the stable character of mango kernel fat against oxidative deterioration. The fatty acid profile constituted palmitic acid (CI6:0; 8.43%), stearic acid (CI8:0; 34.98%), oleic acid (CI8:1 cis; 48.05%), linoleic acid (CI8:2; 6.60%) and arachidic acid (C20:0; 1.73%). Trace amounts of C16:1 (0.56%), C18:1 trans (0.25%), C18:3 (0.43%), C20:1 (0.25%) and C22:0 (0.40%) were also found. The freshly pressed MKF had a peroxide value of 2.7 meq.kg", CD value of 0.07% and an AV of 2.2 mmol.kg", After 40 days of storage, the peroxide values of MKF stored with and without exposure to a limited amount of oxygen at 5, 15,25 and 40°C increased to 5 meq.kg" and 4 meq.kg" respectively. Emulsification of MKF had a stabilising effect (maximum PV = 2.8 meq.kg'), while exposure to UV light had a catalysing effect (maximum PV = 5 meq.kg'). These maximum values, decreased after 40 days. The CD values of MKF samples stored with and without exposure to oxygen at 5, 15,25 and 40°C increased to 0.18% and 0.16%, respectively at day 40. The CD values of samples exposed to light increased to 0_20% and the emulsified samples showed similar values to that of the MKF samples not exposed to oxygen. The conjugated diene values remained stable after day 40. The p-anisidine values of the MKF samples both stored with and without exposure to oxygen at 5, 15, 25 and 40°C varied between 0.5 and 5 mmol.kg". The weak correlation to the measurement of nonanal, as well as the low levels of 2-alkenals produced by the MKF, resulted in these low and sometimes non-linear values. The peroxide, conjugated diene and p-anisidine values obtained for MKF stored at 25°C over 240 days were low due to the low content of polyunsaturated fatty acids in MKF. This compared favourably with the higher values attained for sunflower, canola and olive oil, which are all rich in polyunsaturated fatty acids. The minimal changes observed in the fatty acid profile of mango kernel fat indicated the stability of the saturated fatty acids (CI6:0 and CI8:0) and oleic acid. In addition, the instability of linoleic and linolenic acids was evident due to oxidative deterioration. A decrease of 7.41% and 12.80% was observed between day 0 and 240 for the C18:2/C16:0 and C18:2/C18:0 ratios respectively. The prediction of the oxidative status of the MKF samples by near infrared spectroscopy were possible after the development of calibration models from a total data set of 300 samples of which one-third was used for independent validation. Principle component analysis (PCA) indicated classification at 0, 40 and the remaining (80 - 240) days. The best calibration model for PV yielded a SEP (standard error of prediction) of 0.46 meq.kg", correlation coefficient (r) of 0.95, bias of 0.02 and a root mean square error of prediction (RMSEP) of 0.46 meq.kg". The CD calibration model had a correlation coefficient of 0.89, SEP of 0.01 %, bias of 0.001 and RMSEP of 0.01% when developed on a data set with no pre-processing applied. The AV calibration had a SEP of 0.32 mmol.kg", bias of 0.03, RMSEP of 0.32 mmol.kg" and rof 0.93. The C18:2 and C18:3 models were built using partial least squares (PLS) regression and the values obtained for SEP were 0.31% and 0.054%, RMSEP 0.32% and 0.05%, bias 0.05 and 0.01 and correlation coefficcients were 0.82 and 0.54 respectively. The calibrations for CI8:1, C18:0 and C16:0 yielded weaker correlations. Good correlations were obtained when calibrating the CI8:2/CI6:0 and C18:2/CI8:0 ratios.
AFRIKAANSE OPSOMMING: Die oksidatiewe stabiliteit van ru, koud-geperste mango kern vet (MKV) (Mangifera indica L.) is oor 'n periode van 240 dae bepaal deur gebruik te maak van die peroksiedwaarde (PV), gekonjugeerde dieen waarde (CD) en p-anisidien waarde (AV) toetse. Die veranderinge in die vetsuurprofiel is gemonitor deur gaschromatografie en die oksidatiewe status van MKV is akkuraat voorspel word deur Fourier transformasie naby infrarooi (FT-NIR) spektroskopie. Die resultate van die verskillende toetsmetodes komplementeer mekaar goed en dui die stabiliteit van mango kern vet teen oksidatiewe verval aan. Die vetsuurprofiel is saamgestel uit palimitiensuur (C16:0; 8.43%), steariensuur (C18:0; 34.98%), oleïensuur (C18:1 cis; 48.05%), linoleïensuur (C18:2; 6.60%) en aragiedsuur (20:0; 1.73%). Spoorhoeveelhede C16:1 (0.56%), C18:1 trans (0.25%), C18:3 (0.43%), C20:1 (0.25%) en C22:0 (0.40%) is ook geïdentifiseer. Die vars geperste MKF het 'n peroksiedwaarde van 2.7 meq.kg", 'n CD waarde van 0.07% en 'n AV waarde van 2.2 mmol.kg" getoon. Na afloop van 40 dae opbergingsperiode by 5, 15, 25 en 40°C het die PV van MKV met 'n beperkte blootstelling aan suurstof na 5 meq.kg" vermeerder, terwyl die waardes van monsters sonder suurstofblootstelling na 4 meq.kg" vermeerder het. Emulsifisering van MKV het 'n stabiliserende effek (maksimum PV = 2.8 meq.kg") terwyl blootstelling aan ultraviolet (UV) lig 'n kataliserende effek (maksimum PV = meq.kgl ) op oksidasie gehad het. Hierdie maksimum waardes het na 40 dae afgeneem. Die CD waardes van MKF monsters opgeberg by 5, 15, 25 en 40°C en met beperkte blootstelling aan suurstof het vermeerder tot 0.18% terwyl die monsters sonder suurstofblootstelling by bogenoemde temperature vermeerder het tot 0.16% na 40 dae. Die gekonjugeerde dieen waardes van die monsters blootgestel aan UV lig het vermeerder tot 0.20%; terwyl die geëmulsifiseerde monsters waardes soortgelyk aan die MKV monsters sonder blootstelling aan suurstof getoon het. Gekonjugeerde dieen waardes het gestabiliseer vanaf dag 40. Die p-anisidienwaardes van MKV monsters opgeberg by temperature van 5,15, 25 en 40°C, met en sonder blootstelling aan suurstof, het varieer tussen 0.5 en 5 mmol.kg". Die swak korrellasie tussen nonanal produksie en p-anisidienwaardes, sowel as die klein hoeveelhede 2-alkenale geproduseer, was verantwoordelik vir hierdie lae en nie linêere waardes. Die peroksied, gekonjugeerde dieen en p-anisidienwaardes wat verkry is nadat MKV by 25°C in 240 opgeberg is, was laag weens die klein persentasie poli-onversadigde vetsure teenwoordig in die vet. Dit vergelyk goed met die hoë waardes wat verkry is vir sonneblom-, canola- en olyfolie wat almal ryk aan poli-onversadigde vetsure is. Die minimale veranderinge in die vetsuurprofiel van MKF dui op die stabiliserende invloed van versadigde vetsure (C16:0 en C18:0) en oleïensuur. Die onstabiliteit van linoleïen- en lineensuur duidelik uit hierdie vetsure se oksidatiewe verval. 'n Afname van 7.41% en 12.80% is waargeneem tussen dae 0 en 240 vir die C18:2/C16:0 en C18:2/C18:0 verhoudings, onderskeidelik. Die voorspelling van die oksidatiewe status van die MKF monsters met behulp van FT-NIR spektroskopie was moontlik deur die ontwikkeling van kalibrasie modelle. 'n Totale datastel van 300 monsters, waarvan ongeveer 'n derde vir validasie aangewend is, is gebruik vir die kalibrasiemodelle. Met behulp van PCA (hoojkomponent analise) kon drie klassifiseerbare groepe by 0, 40 en 80-240 dae onderskei word. Die beste kalibrasiemodel vir PV het 'n standaardfout van voorspelling (SEP) van 0.46 meq.kg", 'n korrellasiekoëffisient (r) van 0.95, 'n oorhelling van 0.02 en 'n standaardfout van voorspelling (RMSEP) van 0.46 meq.kg" gehad. Die CD kalibrasiemodel (geen voorafverwerking) het 'n r van 0.89, SEP van 0.01% oorhelling van 0.001 en RMSEP van 0.01% gehad. Die AV kalibrasie het 'n SEP van 0.32 mmol.kg', oorhelling van 0.03, RMSEP van 0.32 mmol.kg" en r van 0.93 gehad. Die C18:2 en C18:3 modelle is saamgestel deur PLS (partial least squares) regressie. Waardes verkry vir C18:2 en C18:3 was onderskeidelik: SEP 0.32% en 0.05%, RMSEP, 0.32% en 0.05%, oorhelling 0.05 en 0.01 en r 0.82 en 0.54. In die geval van C18:1, C18:0 en C16:0, het die kalibrasies swakker statistiek korrellasies getoon. Goeie korrellasies is verkry tydens kalibrasie vir die C18:2/C16:0 en C18:2/C18:0 verhoudings.

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Li, Hui 1970. "Analysis of edible oils by Fourier transform near-infrared spectroscopy." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36819.

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Fourier transform near-infrared (FT-NIR) spectroscopy was investigated as a means of quantitative analysis of edible fats and oils. Initially, a method of simultaneously determining the cis and trans content, iodine value and saponification number of neat fats and oils using a heated transmission flow cell was developed. Two partial least squares (PLS) calibrations were devised, a process-specific calibration based on hydrogenated soybean oil and a more generalized calibration based on many oil types, the latter able to analyze oils from a variety of sources accurately and reproducibly. Methodology for the quantitative determination of the peroxide value (PV) of edible oils using a novel glass-vial sample handling system was subsequently developed, based on the stoichiometric reaction of triphenylphosphine with hydroperoxides to form triphenylphosphine oxide. The PV calibration was derived using PLS regression, and the results of a validation study demonstrated that PV could be quantitated accurately if a normalization routine was used to compensate for the inherent dimensional variability of the vials. The vial sample handling system was then used in the development of PLS IV calibrations for the process analysis of commercial oil samples, and these samples were also used to evaluate a global IV calibration devised by Bomem Inc. The discriminant features available through PLS were shown to enhance the accuracy of the IV predictions by facilitating the selection of the most appropriate calibrations based on the spectral characteristics of closely related oils. The predictions obtained using the global IV calibration provided clear evidence that a generalized calibration based on a large and varied selection of oils could provide a means of IV determination by FT-NIR spectroscopy. Subsequently, a generalized FT-NIR trans calibration was developed and shown to yield trans values that were in good agreement with those obtained by the AOCS mid-FTIR single-bounce hori

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Zamani, Younes. "Determination of physical characteristics of food fats." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0007/MQ44324.pdf.

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Lazarick, Kelsey. "Cause of color component formation in oils during frying." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Chemistry and Biochemistry, c2012, 2012. http://hdl.handle.net/10133/3303.

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Color formation in oils during frying is one of the most noticeable degradation reactions that occur in the frying oil. Degradation reactions cause formation of products that positively and negatively impact the nutritional and sensory qualities of both the food being fried and the frying oil. The origins of these pigment forming reactions in the oil and the factors affecting these reactions are not well understood. Assessments of the mechanisms, the components involved and external conditions affecting oil darkening were conducted. The effect of basic food ingredients, commercially sold and laboratory formulated breading and battering, preformed lipid hydroperoxides and phospholipids on color formation and oil degradation of the frying oil were investigated. Protein products, specifically whey protein, caused both the fastest darkening and thermo-oxidative deterioration of the frying oil. This breakdown was aided further through the addition of minor food materials such as glucose and amino acids as well as lipid hydroperoxides in concentrations greater than 5 % of the frying oil. Nonenzymatic browning is the main reaction causing color formation in the frying oil and utilizes carbonyls from the food product such as starches, sugars and lipid oxidation products as starting materials alongside amino groups from proteins and amino acids. Breading ingredients contributed to oil color formation due to particles from the food crust breaking off into the frying oil to further accelerate browning reactions. Increasing the temperature of the frying oil provided additional stimulus for color forming and thermo-oxidative reactions to progress at a faster rate.
xv, 184 leaves : ill. ; 29 cm

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Rindt, Allyson. "Consumer acceptance of cranberry seed oil in several food formulations." Online version, 2008. http://www.uwstout.edu/lib/thesis/2008/2008rindta.pdf.

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Sedman, Jacqueline. "Application of Fourier transform infrared spectroscopy in the analysis of edible fats and oil." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36833.

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The application of Fourier transform infrared (FTIR) spectroscopy in the assessment of oil quality and stability and the determination of the degree and type (cis or trans) of unsaturation of fats and oils was investigated. FTIR spectroscopy was shown to provide a rapid means of monitoring changes in oils undergoing oxidation or subjected to thermal stress. Absorption bands associated with common primary and secondary oxidation products were identified by relating them to those of spectroscopically representative reference compounds, and a quantitative approach based on the use of oils spiked with these reference compounds as calibration standards was proposed. A sample-handling accessory based on a heated 25-mum transmission flow cell and heated input and output lines was developed to facilitate the rapid analysis of oils and premelted fats in their neat form. Using this system, an FTIR edible oil analysis package was developed to simultaneously analyze for trans content, cis content, iodine value (IV), and saponification number (SN) of neat fats and oils, using partial-least-squares (PLS) calibrations based on pure triglycerides. An automated transmission-based peak height method for isolated trans isomer determination using the characteristic trans absorption band at 967 cm -1 in the spectrum of a neat fat or oil, ratioed against the spectrum of a trans-free oil, was also developed. A subsequent validation study involving the analysis of more than 100 oil samples demonstrated concurrence between the trans data obtained by the PLS and peak height FTIR methods as well as between IV results obtained by FTIR analysis and gas chromatography. In addition, the internal consistency of the IV, cis, and trans FTIR predictions provided strong experimental evidence that the FTIR edible oil analysis package measures all three parameters accurately. A PLS-based IV/trans method was developed for a heated single-bounce horizontal attenuated total reflectance (SB-HATR) sample-

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Mottram, Hazel Rosemary. "The application of HPLC-APCI MS to the regiospecific analysis of triacylglycerols in edible oils and fats." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285582.

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Midson, Kerri. "Comparative deterioration of frying oil due to different heat exchangers /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17848.pdf.

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Memon, Khalida Perveen. "Solid fat index determination by Fourier transform (FTIR) spectroscopy." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24028.

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This work describes an investigation of the development of a Fourier Transform Infrared (FTIR) spectroscopic method for the determination of Solid Fat Index (SFI) of fats as a possible replacement of the traditional dilatometric procedure. The initial approach considered was the use of an existing FTIR analytical package which was designed to measure iodine value (IV), saponification number (SN), and cis and trans content. It was hypothesized that these measures could be related to SFI using multiple linear regression (MLR), thereby allowing the existing analytical package to simultaneously make SFI measures. It was found that there was a strong relationship between SN/cis/trans measurements and SFI, especially in sequentially hydrogenated oils. The MLR relationships, however, did not reproduce the dilatometric SFI values with sufficient accuracy in the general case, and this approach had to be abandoned. Subsequently, a partial least squares (PLS) calibration approach was investigated, relating the dilatometric SFI data directly to the spectral characteristics of the melted fats. It was found that suitable PLS calibrations could be developed for soybean and Canola oils. Based on these results, an FTIR system was programmed to determine SFI and the performance of the system validated using pre-analyzed "unknowns". It was shown that the SFI of either soybean or Canola oils could be determined to within $ pm$ 1.0 SFI. As configured, the FTIR system is capable of determining the SFI of a neat and clear, melted fat sample at 80$ sp circ$C in less than two minutes, providing four SFI values, representing the solids content at 50, 70, 80 and 92$ sp circ$F. In contrast to the standard dilatometric method, which takes over two hours to carry out, the FTIR approach provides a rapid means of determining SFI, the technique being suitable for routine quality control applications in the fats and oils industry.

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Robertson, Katherine Anne. "Effect of flour protein content on the utilization of shortening and cellulose in biscuits." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45172.

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Biscuits were prepared from eighteen different recipe formulations. The biscuits were made from flour containing 7.53%, 8.99%, and 10.05% protein with 30, 40, and 50 grams of shortening and 0 or 2.2 grams of microcrystalline cellulose (MCC). Biscuit quality was assessed by objective and sensory evaluation. The caloric content of the biscuits was also determined by bomb calorimetry. No significant differences were detected in biscuit volume, crumb and crust color, or tenderness. The biscuits prepared with lower levels of shortening were moister than the biscuits prepared with higher levels of shortening. Wo significant differences were found by sensory panelists with regard to evenness of exterior color, aroma, evenness of cell structure, size of cell structure, interior color, center moistness, tenderness, biscuit flavor, or aftertaste. Flakiness and exterior color were found to be significantly different. Biscuits with added MCC were detected to be less flaky. Biscuits prepared from medium protein level flour and low-shortening with MCC were darker than high-shortening biscuits without MCC. High-protein, high-shortening biscuits with MCC were darker than medium-protein, high-shortening biscuits without MCC. The caloric content of the biscuits prepared with lower amounts of shortening was found to be significantly less than biscuits prepared with the higher levels of shortening. In conclusion, high quality biscuits can be produced from flour of varying protein content with less shortening and without the incorporation of MCC.
Master of Science

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Kamm, Willibald. "Authenticity control of edible fats and oils by analysis of minor constituents via on-line liquid chromatography - gas chromatography." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965254364.

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朱翠珊 and Tsui-shan Chu. "Factors affecting the structure and oil content of steamed-and-fried instant noodles." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31222511.

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Chu, Tsui-shan. "Factors affecting the structure and oil content of steamed-and-fried instant noodles /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22053955.

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Allendorf, Meghan E. "Application of a Handheld Portable Infrared Sensor to Monitor Oil Quality." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1289152348.

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Kupranycz, Donna B. (Donna Bohdanka). "Effects of thermal oxidation on the constitution of butterfat, butterfat fractions and certain vegetable oils." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72822.

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Al-Alawi, Ahmed Ali. "Novel approaches to automated quality control analyses of edible oils by Fourier transform infrared spectroscopy : determination of free fatty acid and moisture content." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100311.

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Three new quantitative Fourier transform infrared (FTIR) spectroscopic methods were developed for the analysis of edible oils: two procedures to measure free fatty acids (FFA) and one to measure moisture (H2O), the latter two methods ultimately being automated and implemented on an auto-sampler equipped FTIR spectrometer. The methods developed for FFA determination both convert FFAs to their carboxylate salts by means of acid/base reaction without causing oil saponification, one approach using 1-propanol, an oil-miscible solvent, and the other using methanol, an oil-immiscible solvent into which the FFA salts are extracted. The first method involves splitting oil samples into two halves, with one half treated with propanol containing base and the other half with propanol only. The spectra of each half is collected and a differential spectrum obtained, from which quantization is performed. The methanol procedure simply involves extracting FFA into methanol containing a weak base and quantitating the FFA salts produced. Both FFA methods determine the FFA content by measuring the v (COO-) absorbance at ∼1570 cm-1 relative to a reference wavelength of 1820 cm-1 from a differential spectrum relative to the solvent, the extraction procedure being superior in terms of both speed and sensitivity, being able to measure FFA levels down to ∼0.001%. The method developed for moisture determination involves extracting water in edible oils into dry acetonitrile and then quantitating it by measuring the absorbance of the OH stretching band (3629 cm-1) and/or the HOH bending band (1631 cm -1). All three methods were validated by standard addition experiments, evaluated for potential interferences, and, in the case of FFA determination, compared to the performance of AOCS official methods. The results indicated that the extraction-based procedures were superior to conventional wet chemical methods in both sensitivity and reproducibility. The FFA and H2O extraction procedures were subsequently automated by connecting an auto-sampler to the FTIR spectrometer and developing procedures and software algorithms to enable the analysis of up to 100 samples/h. The methods developed and implemented are a substantive improvement over conventional methods for the analysis of FFA and H2O in edible oils and provide a means by which QC and process laboratories can analyze large volumes of edible oils for these two important parameters.

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22

Cha, Ming Chuan 1955. "Effects of dietary fat selection and energy restriction on tissue lipid metabolism : structure, function and regulation." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35684.

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To investigate interactive effects of dietary fatty acid composition and energy restriction on body lipid metabolism and its regulation, rats were fed for 10 weeks diets varying in fat type and energy intake level. Energy deficiency was achieved by removing carbohydrate from the diets while keeping fat and other nutrient intakes constant. Tissue fatty acid deposition was influenced by the interaction between the dietary fat source and body energy balance. Less total fatty acids were deposited in livers of the ad libitum beef tallow-fed animals than the other fat feedings. However, such difference no longer existed when energy intake was restricted. Similarly, less energy supply eliminated the higher docosahexaenoic acid and lower arachidonic acid contents associated with the fish oil feeding in hepatocyte membrane phosphatidylchohne, phosphatidylserine and sphingomyelin. Tissue lipogenesis was also examined as a function of the interaction of dietary fatty acid composition and energy restriction. Comparable absolute cholesterol synthesis rates were observed in livers of the food restricted animals fed different types of dietary fat, although the synthesis rates were different among the dietary fat groups fed ad libitum. Energy restriction increased the triglyceride-fatty acid synthesis rates in the intestine of the fish and safflower oil-fed groups, but not in that of the olive oil- and beef tallow-fed animals. Plasma leptin concentrations were 60% higher in the ad libitum-fed fish and safflower oil groups as compared with those in the beef tallow diet group, despite smaller perirenal fat mass and fat cell size in the fish oil-fed animals. Energy restriction decreased plasma leptin levels of the fish and safflower oil-fed rats, but not those in the beef tallow-fed animals. Taken together, these results demonstrate that the structural, functional and regulating aspects of tissue lipid metabolism were influenced by an interaction between dietary fatty acid composit

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23

Ma, Kangming 1965. "Peroxide value and trans analyses by Fourier transform infrared (FTIR) spectroscopy." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36643.

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New Fourier transform infrared (FTIR) approaches for the quantitative determination of peroxide value (PV) and isolated trans analyses were investigated and developed. The FTIR-PV methods investigated were all based on the stoichiometric reaction of hydroperoxides and triphenylphosphine (TPP) which converts TPP to triphenylphosphine oxide (TPPO). A reference transmission cell (100 mum) method was developed based on the use of a unique TPPO absorption at 542 cm-1. This method covered PV values from 0--15 PV and was shown to be superior in accuracy and reproducibility to the standard American Oil Chemists Society (AOCS) iodometric method. Subsequently, the utility of disposable polyethylene cards, normally used only for qualitative analyses, was investigated for quantitative PV determination. A quantitative IR card method was successfully developed and shown to serve as a very simple, rapid and alternative means of carrying out PV analyses. TPP-impregnated cards were able to reproduce the transmission cell PV results to +/-1.12 PV, while the unimpregnated card was slightly more accurate (+/-0.92 PV). A third FTIR-PV method was developed specifically for the at-line monitoring of high PV fatliquors and employed a germanium attenuated total reflectance sample handling accessory. This method hinged on the use of a TPPO absorption band at 1118 cm-1, normally off scale when pathlengths of >3 mum are used, but is suited to the analysis of oils having very high PVs (>250). The successful quantitative use of the disposable polyethylene IR card to PV led to its study for the quantitative FTIR determination of the isolated trans content of fats and oils and margarines. The polyethylene card was shown to unique and useful properties, tending to inhibit fat crystallization and its inability to retain moisture. These two properties allowed trans determination to be carried out on melted, high trans fats, without heating the polyethylene substrate and also to analyze margarines

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Ubhayasekera, S. J. Kumari A. "Sterols and oxysterols : occurrence and analysis in by-products feed fats and animal tissues /." Uppsala : Dept. of Food Science, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200947.pdf.

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Muniz, Adriana. "Efeito da adição do óleo de soja, óleo de linhaça, óleo de coco babaçu e sebo bovino nos parâmetros produtivos e reprodutivos de fêmeas suínas em lactação." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/10/10131/tde-28082007-095434/.

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O objetivo do experimento foi verificar o efeito da adição do óleo de soja, óleo de linhaça, óleo de coco babaçu e sebo bovino na ração de fêmeas suínas lactantes. As dietas eram energeticamente altas, sendo uma dieta basal acrescida em 8% por diferentes fontes de energia, (1) óleo de soja, (2) óleo de linhaça, (3) óleo de coco e (4) gordura animal, tratamentos 1, 2, 3 e 4 respectivamente. O experimento foi realizado na Fazenda Santa Rosa, Leme, SP. As variáveis avaliadas foram peso inicial, aos 100 dias de gestação (PI), peso à desmama (PD), espessura de toucinho aos 100 dias de gestação (ETI), espessura de toucinho à desmama (ETD), mudanças corporais no período lactacional como perda de peso (PP), perda de espessura de toucinho (PET), produção de leite (PL) e peso dos leitões (Ple) nos dias 7, 14 e 21 da lactação, intervalo desmama estro (IDE), duração do estro (DE) e concentrações de estrógeno (Es) à desmama, 48 horas após a desmama e no estro. A espessura de toucinho foi medida no P2. A técnica de PL foi realizada pela técnica de peso dos leitões antes e depois das mamadas. O manejo para diagnóstico do estro foi realizado duas vezes ao dia. As coletas de sangue foram realizadas em 3 ocasiões à desmama (Dia 1), 48 horas após a desmama (Dia 2) e na comprovação do estro (Dia 3). As análises da (Es) foram realizadas pela técnica de radioimunoensaio. Foram utilizadas 24 fêmeas, em um delineamento inteiramente ao acaso. Os resultados foram analisados através do programa computacional Statistical Analysis System (SAS Institute Inc., 1985) submetidos à análise de variância pelo procedimento GLM (PROC GLM). Para os valores de peso, espessura de toucinho, bem como das mudanças no período não houve diferença significativa, e os resultados foram para PI 257,7; 259,3; 265,0 e 267,0 quilos e para PD 231,3; 217,4; 224,9 e 225,0 quilos para os tratamentos 1, 2, 3 e 4, respectivamente. Os valores de 17,0; 16,5; 16,5; 16,0 milímetros foram para ETI e 13,2; 12,13; 12,5 e 12,0 mm para ETD nos tratamentos 1, 2, 3 e 4, respectivamente. A PP durante a lactação foi de 44,4; 41,9; 40,1 e 39,1 para os tratamentos 1, 2, 3 e 4, respectivamente. Já a PET apresentou médias de 3,8; 4,2; 4,0 e 4,0 mm nos tratamentos 1, 2, 3 e 4, respectivamente. Não foi encontrada diferença significativa para PL, bem como para os diferentes dias de mensurações tendo como resultados no 7º dia 10,13; 9,43; 8,98 e 8,85 Kg para os diferentes tratamentos 1, 2, 3 e 4, respectivamente. No 14º dia os valores médios para os tratamentos foram de 10,12; 11,20; 10,26 e 8,79 Kg, respectivamente, e os valores de 11,34; 10,47; 10,56 e 10,76 Kg para os tratamentos 1, 2, 3 e 4, respectivamente para o 21º dia. O peso dos leitões não foi significativo entre os tratamentos, mas apresentou significância nos três diferentes tempos (P < 0,01) e os valores médios foram de 2,87; 2,95; 2,83 e 2,9 Kg para os tratamentos 1, 2, 3 e 4, respectivamente para o 7º dia de amamentação, de 5,01; 4,88; 4,8 e 4,75 Kg nos tratamentos 1, 2, 3 e 4, respectivamente para 14º dia. Já para o 21º dia os valores nos tratamentos 1, 2, 3 e 4, respectivamente foram de 6,80; 6,58; 6,56 e 6,82 Kg. O IDE e DE não apresentaram diferença significativa e tiveram como médias nos respectivos tratamentos 1, 2, 3 e 4 de 74,0; 68,0; 70,3 e 78,7 horas para IDE e 57,6; 62,0; 64,0 e 72,0 para DE. Para as médias de Es não houve significância e estas apresentaram os seguintes valores de 10,25; 12,82; 9,65 e 8,71 pg/ml nos respectivos tratamentos 1, 2, 3 e 4 no dia 1. Para o dia 2 os valores nos tratamentos 1, 2, 3 e 4 foram de 25,8; 27,39; 24,64 e 32,12 pg/ml respectivamente, e os valores de 83,6; 79,14 e 77,64 pg/ml para os tratamentos 1, 2, 3 e 4, respectivamente referentes ao dia 3.
Twenty-four Dalland C40 sows were used in one experiment to study the effect of dietary vegetable oil or tallow on productive and reproductive parameters. All sows were fed a corn-soybean meal diet supplemented with 8% soybean (T1), linseed (T2), coconut (T3) oil or tallow (T4) from day 100 of gestation and throughout the lactation period. Sow initial weight and backfat thickness were determined at day 100 of gestation (ISW and IBT, respectively), and at weaning (WSW and WBT, respectively). Sow weight and backfat thickness losses (WL and BTL, respectively) were calculated, and milk yield (MY) was estimated at day 7, 14 and 21 of lactation by weighing the litter before and after suckling. Interval weaning estrus (IWE), and estrus duration (ED), and piglet weight (PW) were recorded. Blood samples were taken at weaning (day 1), and 48 hours after weaning (day 2), and at onset of estrus (day 3) for estradiol (E2) determination. There were no treatment effects for the parameters studied. The means for E2 were 10.25; 12.82; 9.65 e 8.71 pg/ml (day 1), and 25.8; 27.39; 24.64 e 32.12 pg/ml (day 2), and 83.6; 79.14 e 7764 pg/ml (day 3) for treatment 1, 2, 3 e 4, respectively. Means for E2 on day 3 were higher than values observed on day 1 and 2.

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López, Sabater María del Carmen. "Evolución de los parámetros químicos del aceite a lo largo de la maduración de las aceitunas del Montsiá." Doctoral thesis, Universitat de Barcelona, 1985. http://hdl.handle.net/10803/673081.

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Cataluña es una zona con una producción considerable de aceite de oliva (aproximadamente 17.500 toneladas anuales). Sin embargo, posee unas características de producción y/o elaboración muy variables según la comarca considerada, lo cual hace que los aceites producidos tengan una calidad diferente. En realidad, podemos considerar la existencia de tres zonas productoras, Les Garrigues (Borges Blanques), Siurana y Baix Ebre-Montsià, teniendo las dos primeras la Denominación de Origen correspondiente, caracterizada por un monocultivo de la variedad Arbeguina. La zona de Baix Ebre-Montsià se caracteriza, al contrario de las anteriores, por el cultivo de tres variedades (Farga, Sevillenc y Morrut) aunque, con carácter minoritario, se cultivan otras. Este hecho, junto con diferentes factores de tipo sociológico, métodos de recolección y elaboración poco actualizados, hace que, a pesar de ser la zona con mayor producción, la calidad final del aceite tenga unas características muy variables. Estos son los motivos que nos han inducido a concretar el estudio en esta zona, con el fin de colaborar en la mejora de calidad de los aceites. La legislación relativa a los aceites vegetales comestibles ( B.O.E. de 29-2-83) es cada vez más estricta, lo cual implica que los aceites vírgenes elaborados en el Montsià, no puedan ser comercializados como tales, sino que normalmente se destinan para la elaboración de aceites de oliva "puros" o incluso "refinados”. De lo dicho anteriormente, se deduce un primer objetivo del trabajo, estudiar desde un punto de vista químico las características de estos aceites para poder concluir cuáles son algunos de los factores que inciden negativamente sobre la calidad de los mismos. Para ello es preciso conocer, en primer lugar, las diferencia= entre las distintas variedades de aceitunas, tanto en los componentes mayoritarios (ácidos grasos), como compuestos minoritarios (componentes del insaponificable ), De esta forma, se reúnen los objetivos principales de este trabajo, es decir, conocer las características de las distintas variedades de aceitunas, establecer de qué forma evolucionan los diferentes parámetros de calidad e incluso los componentes minoritarios a lo largo del proceso de maduración, con el fin de establecer el punto óptimo de recolección y llegar a definir, si es posible, los parámetros que permitan tipificar las diferentes variedades de aceituna.

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Garcia, Mendoza Maria del Pilar. "Enrichissement d’huiles végétales par des antioxydants de type phenolique en vue d’applications alimentaires." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0196.

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Les huiles végétales comme les huiles de cameline et tournesol sont des sources d’acides gras polyinsaturés bon pour la santé mais également très sensibles à la dégradation oxydative. Ce travail vise à améliorer la stabilité oxydative d’huiles alimentaires (principalement l’huile de cameline) via l’incorporation de composés phénoliques antioxydants soit comme composé pur (quercétine) soit comme un mélange plus complexe extrait à partir d’un coproduit de la noix. La faible solubilité de la quercétine dans l’huile a été contournée avec succès par le développement d’une voie d’enrichissement sans solvant en présence de phospholipides. Ainsi, la formulation à base de quercétine-phospholipides a permis d’augmenter significativement à la fois la solubilité de la quercétine and la stabilité oxydative de l’huile. Cette stabilité oxydative, mesurée par vieillissement accéléré à chaud, s’est révélée variable selon les concentrations en quercétine et phospholipides. L’hypothèse du rôle central des associations colloïdales dans ces observations a été formulée. Des données sur la solubilité de la quercétine dans différents solvants d’intérêt industriel ont également été générées. Pour les extraits phénoliques à base de tourteau de noix, en plus de l’amélioration de la stabilité oxydative, les paramètres influençant l’extraction ont été identifiés et une modélisation des procédés batch et semi-continu proposée. L’effet protecteur contre l’oxydation de l’huile d’un extrait de noix présentant une haute activité antiradicalaire s’est révélé dose-dépendant et a permis un accroissement significatif de la durée de conservation des huiles enrichies
Vegetable oils like camelina and sunflower oils are sources of healthy polyunsaturated fatty acids that are however highly susceptible to oxidative degradation. This work aimed at enhancing the oxidative stability of edible oils, mostly camelina oil by incorporating phenolics antioxidants, either as a pure component, quercetin, or as a more complex mixture extracted from a walnut by-product. The low solubility of quercetin in oils was successfully circumvented by developing a solvent-free route of enrichment in presence of phospholipids, so that quercetin-phospholipids formulation allowed to significantly increase both quercetin solubility and the oxidative stability of the oils. The enhanced oxidative stability, monitored under accelerated conditions of heating, was found to vary according to quercetin-phospholipid concentrations and ratios, and it was assumed that colloidal associations played a key role in the enhancement. Data of quercetin solubility in various solvents of industrial interest were also provided. For phenolic extract recovered from a walnut press-cake in addition to oxidative stability enhancement, modelling of batch and semi-continuous extractions was performed and influent parameters were identified. The protective effect against lipid oxidation of a walnut extract exhibiting high antiradical activity was dose-dependent and significantly extended the shelf life of enriched oils

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Quast, Leda Battestin. "Estudo do efeito da adição de gorduras alternativas na cristalização da manteiga de cacau." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266281.

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Orientadores: Theo Guenter Kieckbusch, Valdecir Luccas
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-08-10T18:45:44Z (GMT). No. of bitstreams: 1 Quast_LedaBattestin_D.pdf: 1972832 bytes, checksum: a34ffd60e85d88858ba49961e507cd34 (MD5) Previous issue date: 2008
Resumo: A influência da incorporação de gorduras alternativas low e zero trans na cristalização da manteiga de cacau foi avaliada através da caracterização física de misturas binárias de manteiga de cacau com gordura de cupuaçu, gordura CBR low trans e gordura CBS, nas proporções de 5, 10, 15, 20, 25 e 30 %. O processo de pré-cristalização (temperagem) foi realizado em um reator encamisado de escala piloto dotado de um agitador e com capacidade para 700 mL. As amostras foram caracterizadas através da curva de sólidos, tensão de ruptura (snap test), calorimetria diferencial de varredura e difração de raios-X. A melhor condição de pré-cristalização da manteiga de cacau pura (taxa de resfriamento de 1,8 ºC/min, cristalização à 24 ºC por um tempo de 8 minutos) também foi utilizada nos ensaios com as misturas, com exceção das amostras com 20, 25 e 30 % de CBR e CBS que foram pré-cristalizadas a 23 ºC por 10 minutos. A manteiga de cacau apresentou um perfil de fusão de gordura na boca, DS(25ºC-35ºC), de 59,2 %, que sofreu apenas pequenas alterações com a adição de até 20 % de cupuaçu e até 30 % de CBR. A curva do conteúdo de sólidos sugere a formação de um eutético entre a manteiga de cacau e a gordura CBS. A tensão de ruptura para a manteiga de cacau foi de 2,48 kgf/cm2 e a adição das gorduras tende a diminuí-la, sendo que com 30 % de cupuaçu e 30 % de CBR esse valor foi 1,90 kgf/cm2 e 1,81 kgf/cm2, respectivamente. Para a amostra com 30 % de CBS a tensão de ruptura baixou para 0,39 kgf/cm2. Observou-se uma diminuição do ponto de fusão das misturas quando comparadas à da manteiga de cacau pura. A difração de raios-X identificou a forma cristalina b como predominante para a manteiga de cacau e para a gordura de cupuaçu enquanto que para as gorduras CBR e CBS a principal forma cristalina é a b'. A incorporação de apenas 10 % das gorduras CBR e CBS à manteiga de cacau promoveu interferências na estruturação cristalina das amostras. O estudo indicou ser possível adicionar até 30 % de gordura de cupuaçu ou CBR e até 10 % de gordura CBS sem alterar de forma sensível os atributos físicos da manteiga de cacau
Abstract: Physical properties of pre-crystallized cocoa butter with the addition of alternative low and zero trans fats were studied. Binary mixtures of cocoa butter were conducted using cupuassu fat, CBR low trans and CBS at 5, 10, 15, 20, 25 and 30 % (w/w) levels. Pre-crystallization was carried out using a lab scale jacket vessel (700 mL) whit stirring system. Samples were evaluated by means of solid fat content, snap test, differential scanning calorimetry and X-Ray diffraction. The better condition for plain cocoa butter pre-crystallization was determined as follows: cooling rate (1,8 ºC/min), crystallization time (8 minutes), crystallization temperature (24 ºC). These conditions were also used for mixtures precrystallization (tempering). Mixtures with 20, 25 and 30 % of CBR and CBS were pre-crystallized at 23 ºC for 10 minutes. Regarding to solid fat content, cocoa butter fusion profile DS(25ºC-35ºC) was 59,2 %. Similar values were obtained for mixtures with up to 30 % of cupuassu and up to 30 % of CBR fats. Mixtures with CBS fat indicated eutectic effect. Snap value for crystallized cocoa butter was 2,48 kgf/cm2. The snap values decreased with the increase of the alternative fats proportion. Mixtures containing cupuassu fat or CBR have similar trend regarding to snap values profile. For mixtures with 30 % of cupuassu and CBR the snap values were 1,90 kgf/cm2 and 1,81 kgf/cm2, respectively. CBS 30% have the lowest snap value (0,39 kgf/cm2). Similar trend was observed regarding to melting point. Alternative fats incorporation decreased the melting point of the mixtures. Regarding to X-Ray diffraction, cocoa butter and cupuassu fat patterns results showed the formation of ß phase. For CBS and CBR patterns, there are evidence of ß¿ phase formation. The addition of 10 % CBR and CBS fat to cocoa butter was detected by X-ray diffraction patterns. The addition of up to 30 % cupuassu or CBR fat, and up to 10 % CBS butter showed no significant differences of physical properties when compared to cocoa butter
Doutorado
Engenharia de Processos
Doutor em Engenharia Química

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Pacheco, Selma Guidorizzi Antonio. "Estabilidade oxidativa de óleo de peixe encapsulado e acondicionado em diferentes tipos de embalagem em condição ambiente." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-16052005-170631/.

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Tem havido um avanço em pesquisas de produtos marinhos, especialmente devido à presença de ácidos graxos poliinsaturados (AGPI), eicosapentanóico (EPA) e docosahexaenóico (DHA), que são abundantes em óleos de peixe e contribuem para a redução dos índices de triacilglicerol e colesterol no sangue. Contudo, os ácidos graxos poliinsaturados são propensos à oxidação. Quanto maior o grau de insaturação do óleo, menos estável ele é, podendo ocorrer comprometimento das duplas ligações devido à oxidação. Essa pesquisa teve como objetivo estudar a estabilidade de óleo de peixe encapsulado acondicionado em diferentes tipos de embalagens. O óleo utilizado nesse experimento foi cedido pela indústria farmacêutica Cardinal Health Brasil, já refinado e em cápsulas gelatinosas moles. Após a encapsulação, a metade dessas cápsulas foi enviada à Empresa SERPAC Comércio e Indústria Ltda. para o processo de emblistagem, em que foram utilizados os filmes policlorotrifluoroetileno (PCTFE), comercializado sob o nome Aclar Rx 160 (15µ), cloreto de polivinilideno (PVDC-60 gsm2) e policloreto de vinila (PVC-250µ) e, posteriormente, acondicionados em caixas de papel cartonado. O restante foi acondicionado em frascos de polietileno de alta densidade (PEAD) com e sem sachês de sílica e em vidro de cor âmbar. Cada frasco ou embalagem cartonada contendo 60 cápsulas foi armazenado em triplicata sob temperatura ambiente e o óleo analisado a cada 28 dias por um período de 12 meses. As análises realizadas mensalmente no óleo foram a determinação da acidez, do índice de peróxido e da absortividade em 232 e 270nm. A composição em ácidos graxos por cromatografia gasosa, especialmente os teores de EPA e DHA, foi determinada no início, aos 3, 6 e 12 meses. A embalagem em que o óleo apresentou as maiores alterações foi o blister de filme PVC. O melhor desempenho foi encontrado no óleo encapsulado, acondicionado na embalagem de PEAD com dessecante de sílica. Os teores de DHA e EPA mantiveram-se estáveis até o sexto período, ocorrendo uma queda considerável no décimo segundo período no óleo da embalagem do filme PCTFE, devido provavelmente a problemas de a termosoldagem e selagem.
Due to the presence of long chained omega three fatty acids, fish oils have gathered much interest recently. Fish oils are a rich source of polyunsaturated fatty acids (PUFA) like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which reduce blood triacylglycerol and cholesterol levels. However, the higher the unsaturation level, the less stable is the oil which may have its double links compromised due to oxidation.This research main interest was the stability of encapsulated fish oil, stored in different types of packagings. The fish oil used in this experiment was supplied by Cardinal Pharmaceutical Industry in soft gel capsules. After encapsulation, half of the samples were sent to SERPAC Industry LTDA for blistering, where polychlortrifluoroethylene (PCTFE), commercially known as Aclar Rx 160 (15µ), polyvinyldichloride (PVDC-60 gsm2) and polyvinylchoride (PVC-250µ) films were used as three of the treatments. Blisters were packed in carton boxes. The other half of the capsules was packed in amber glass or high density polyethylene (PEAD) rigid flasks with and without silica bags. Each treatment contained 60 capsules in triplicate and all packs were stored under ambient conditions for 12 months. Analytical determinations were performed on the oil every 28 days and included acid and peroxide values, and absortivities in the ultraviolet region at 232 and 270 nm. Fatty acid composition determinations, especifically EPA and DHA content were performed at the beginning of the experiment, after 3, 6 and 12 months. The package, which presented the largest changes in quality of the oil, was the PVC film blister. The best results were found in encapsulated oil stored in PEAD flasks with silica bags. EPA and DHA contents were kept constant until the sixth period of storage for all samples. The largest changes happened in the oil stored in PCTFE films, with a drastic reduction on the 12 th period due, probably to problems in thermomolding and sealing.

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De, Wet Martie. "The effect of colonic propionate and the acetate : propionate ratio on risk markers for cardiovascular disease in westernised African men." Thesis, Bloemfontein : Central University of Technology, Free State, 2009. http://hdl.handle.net/11462/30.

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Soares, Fabiana Andreia Schafer de Martini. "Efeito da interesterificação química sobre as propriedades físico-químicas de misturas de estearina e oleína de palma." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/9/9133/tde-10032010-100042/.

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O desafio das indústrias de alimentos na substituição da gordura trans em diversos produtos reside no desenvolvimento de formulações e processos que apresentem funcionalidade equivalente e viabilidade econômica. A interesterificação química representa uma opção tecnológica importante para a produção de gorduras visando diversas aplicações comerciais, sem a formação de ácidos graxos trans. O óleo de palma contém quantidades aproximadamente iguais de ácidos graxos saturados e insaturados e pelo seu fracionamento obtêm-se duas frações: a estearina (fração sólida) e a oleína (fração líquida). A estearina e oleína de palma são opções interessantes para a produção de grande variedade de produtos como margarinas e shortenings. Assim, o objetivo deste trabalho foi modificar as propriedades físico-químicas de misturas de estearina e oleína de palma pelo uso da interesterificação química. As amostras foram analisadas quanto à composição em ácidos graxos e triacilgliceróis, distribuição regioespecífica dos ácidos graxos nos triacilgliceróis, índice de iodo, pontos de amolecimento e de fusão, conteúdo de gordura sólida, consistência e estrutura cristalina. Os ácidos graxos saturados são predominantes na estearina (71,9%), sendo que 65,5% correspondem ao ácido palmítico. A oleína tem como principal constituinte o ácido oléico, que representa 45,4%. À medida que aumenta a proporção de oleína de palma nas misturas, aumentam a quantidade de ácidos graxos insaturados e o índice de iodo e diminui a quantidade de ácidos graxos saturados. Após a interesterificação química, os pontos de fusão e amolecimento, a consistência e o conteúdo de gordura sólida aumentaram nas misturas que apresentavam maior proporção de oleína em função do aumento no teor de triacilgliceróis trissaturados. Por outro lado, estas propriedades não se modificaram nas misturas com maior proporção de estearina. Este comportamento se deve à distribuição aleatória dos ácidos graxos nos triacilgliceróis após a interesterificação, que forma triacilgliceróis em proporções diferentes das existentes originalmente. Os principais triacilgliceróis nas misturas foram PPP, PPO e POO. Antes da interesterificação os ácidos graxos saturados foram encontrados principalmente nas posições sn-1,3. Mudanças significativas na composição dos ácidos graxos na posição sn-2 após a interesterificação química foram encontradas em misturas com mais de 60% de oleína de palma. A mistura e a interesterificação permitiram obter gorduras com diferentes graus de plasticidade, aumentando as possibilidades de uso das frações estearina e oleína de palma.
The challenge of the food industries for the replacement of trans fat in various products lies in the development of formulations and processes which have equivalent functionality and economic viability. The chemical interesterification of palm stearin and palm olein is an important technological option for the production of fats targeting commercial applications, without formation of trans fatty acids Palm oil contains similar amounts of saturated and unsaturated fatty acids. After fractionation two fractions are obtained: stearin (solid fraction) and olein (liquid fraction). Palm stearin and palm olein are alternatives for the production of many products, such as margarines and shortenings. The objective of this work was to modify the physical and chemical properties of mixtures of palm stearin and palm olein by using chemical interesterification. The following properties were analyzed: fatty acid and triacylglycerol compositions, regiospecific distribution of fatty acids in triacylglycerols, iodine value, softening and melting points, solid fat content, consistency and crystal microstructure. Saturated fatty acids are predominant in palm stearin (71.9%), which corresponds to 65.5% of palmitic acid. Palm olein has as its main constituent the oleic acid, which represents 45.4% of the unsaturated fatty acids. The increase of the proportion of palm olein in the mixture causes increase on the amount of unsaturated fatty acids and iodine value and decrease on the content of saturated fatty acids. After chemical interesterification, melting and softening points, consistency and solid fat content increased in the blends that had higher proportion of palm olein, as a consequence of the increase in the trisaturated triacylglycerols. On the other hand, these properties did not alter in the blends with higher proportion of palm stearin. This behavior is due to the random distribution of fatty acids in triacylglycerols after interesterification, which forms triacylglycerols in proportions that are different from those originally present. The major triacylglycerols in the blends were PPP, PPO and POO. Before interesterification the saturated fatty acids were found mainly in the sn-1,3 positions. Significant changes in the fatty acid composition in the sn-2 position after chemical interesterification were found in blends with more than 60 % of palm olein. Blending and interesterification of fats resulted in structured lipids with different degrees of plasticity, increasing the possibilities of use of stearin and olein fractions.

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Dubois, Virginie. "Établissement et stabilisation d'une formulation lipidique équilibrée nutritionnellement : résolution des problèmes de texture et de flaveur, et validation nutritionnelle sur modèle animal." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL064N.

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Les accidents cardio-vasculaires représentent la première cause de décès en France. Parmi les facteurs de risque de ces pathologies figure la structure de l’apport lipidique, excédentaire en acides gras saturés, et déficitaire en acides gras polyinsaturés n-3. L’objectif de cette thèse est la mise au point d’un corps gras alimentaire, dont le profil lipidique permet de participer au rééquilibrage des apports en acides gras, avec comme cible la prévention des maladies cardio-vasculaires.Quatre études ont été réalisées pour répondre à cette problématique. Après la mise au point du profil en acides gras optimal, l’impact de la formulation de la phase concrète sur la texture du produit a été étudié afin de concilier les exigences nutritionnelles et les contraintes techniques de sa fabrication et de sa conservation.La mise au point de la formulation de la phase fluide a engendré une étude sur le développement de composés volatils délétères suite à l’addition d’une proportion importante d’huile de poisson dans la formule. Ce travail a mis en évidence deux phénomènes liés au dégagement de ces molécules, l’un attribué à l’oxydation des lipides, l’autre au contact avec l’eau.Le besoin de protéger les nutriments d’intérêt dans la matrice alimentaire a conduit à la mise au point d’une technologie de microencapsulation, originale de par son procédé de fabrication et sa finalité.Enfin, une étude de la biodisponibilité chez l’animal a montré que ce produit alimentaire est un vecteur efficace de ces nutriments d’intérêt que sont les acides gras polyinsaturés à longue chaîne. Apportés dans une telle matrice, ces composés ont modifié le profil lipidique des cellules circulantes et cérébrales, ce qui permet potentiellement d’améliorer le statut inflammatoire et coagulant des animaux
Cardiovascular events are the major cause of death in France. Among the known risk factors, lipid intake is of growing interest, saturated fatty acids being too much consumed, and n-3 polyunsaturated fatty acids not enough. The aim of this PhD study is to design a spread with a lipid profile that can improve the whole lipid intake, and with cardiovascular events prevention as main goal.Four studies were conducted regarding this issue. Following the design of the optimal fatty acid profile for the product, it appeared necessary to study the solid phase recipe impact on the product texture, to achieve both nutritional and technological restrains.The design of the liquid phase recipe generated a study on the development of deleterious volatile compounds following the addition of a high proportion of fish oil in the formula. This work highlighted two phenomena linked to the emission of these molecules, one related to lipid oxidation, and the other to a contact with water.A technology of microencapsulation, which is original because of its production process and aim, was designed to ensure the protection of the active nutrients in the product matrix.Finally, a bioavailability study in rats showed that this food product is a powerful way of providing these nutrients. Incorporated in such a matrix, these molecules modified the lipid profile of the circulating and cerebral cells membrane, potentially improving the inflammatory and clotting status of the animals

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Esquius, de la Zarza Laura. "Greixos i esports de resistència: avaluació d´estratègies de suplementació aguda amb àcids grassos." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/406121.

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En els darrers anys s’està produint un increment en l’interès i nombre de participants en proves de resistència i ultra resistència. Aquest exercici d’alta intensitat i durada té uns grans requeriments de substrats energètics i també presenta conseqüències importants a nivell inflamatori. S’han revisat els estudis previs que han estudiat diferents estratègies nutricionals per augmentar el rendiment. Algunes d’aquestes estratègies han explorat la utilització de suplementació amb greixos amb l’objectiu d’estalviar les reserves de glucogen muscular, ja que aquests són el principal substrat energètic en aquests esports. La hipòtesi d’aquesta tesi és que una suplementació aguda amb greixos prèvia i durant la pràctica d’esports de residència millora el rendiment i disminueix l’impacte inflamatori produït en exercicis amb grans requeriments energètics. L’objectiu principal és l’avaluació de la influència dels suplements rics en greixos en esforç de llarga durada i elevada intensitat. S’han realitzat quatre experiments. El primer, és un estudi de camp que avalua les repercussions sobre la funció cardiovascular d’una cursa de muntanya de llarga distància. A partir de proves de laboratori, els tres estudis restants avaluen l’efecte de la suplementació rica en greixos i la seva influència en el rendiment, així com el seu efecte antiinflamatori en esforços d’alta intensitat i llarga durada. Realitzats els citats experiments, es demostra la transcendència del metabolisme dels lípids en esforços d’alta intensitat i llarga durada, així com la possibilitat d’utilitzar suplements naturals rics en greixos, ben tolerats i amb una clara influència positiva en el rendiment i en els efectes inflamatoris d’aquests tipus d’exercicis.
In recent years, interest in endurance and ultra-endurance challenges has been growing, as has the number of people taking part in them. Such high-intensity, long-duration exercise has substantial energy substrate requirements and important inflammatory consequences. Previous studies on different nutritional strategies aimed at enhancing performance have been reviewed. Some of those studies explored the use of fat supplementation to save muscle glycogen stores, since the latter are the main energy substrate in these sports. The hypothesis of this thesis is that acute fat supplementation before and during endurance sports improves performance and reduces the inflammatory impact caused by exercises having substantial energy requirements. The aim is to evaluate the influence of supplements rich in fats on long-duration, high-intensity effort. Four experiments were conducted. The first was a field study evaluating the repercussions of a long-distance mountain race on cardiovascular function. Based on laboratory tests, the three other studies evaluated the effect of supplementation rich in fats and its influence on performance, as well as its anti-inflammatory effect in high-intensity, long-duration efforts. Having conducted the aforementioned experiments, the relevance of lipid metabolism in high-intensity, long-duration efforts is demonstrated, as is the possibility of using natural supplements rich in fats, which are well tolerated and have a clear positive impact on performance and on the inflammatory effects of these types of exercises.

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Jehng, Jy-Jier, and 鄭知傑. "High-Temperature Stability of Edible Fats and Oils and the Effects of Food Components on Oxidation Stability of Fats and Oils." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/34075819992211203811.

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Kivevele, Thomas. "Oxidation stability of biodiesel from non-edible oils." 2011. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000630.

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M. Tech. Mechanical Engineering.
Biodiesel, produced from the transesterification of vegetable oils or animal fats with simple alcohol in the presence of a catalyst, is well positioned to replace petroleum-based diesel. Biodiesel is a non-toxic, biodegradable and renewable fuel. Despite its advantages, the chemical nature of biodiesel makes it more susceptible to oxidation compared to mineral diesel during long-term storage. The production of Croton Oil Methyl Ester (COME), Moringa Oil Methyl Ester (MOME) and Jatropha Oil Methyl Ester (JOME) was therefore carried out. Also, a determination of the fuel related properties and investigation of oxidation stability of the methyl esters produced without and with antioxidants and its blends with mineral diesel were conducted. The results showed that most of the measured fuel related properties of produced methyl esters fulfilled the minimum requirements of EN 14214 and ASTM 6751 biodiesel standards. However, COME and MOME did not meet EN 14214 oxidation stability standards (6 h) while JOME displayed very high oxidation stability (10.43 h) well within specified oxidation stability standards. Overall, the biodiesel derived from non-edible oils of African origin such as COME, MOME and JOME can be utilized as a partial substitute for mineral diesel. This study recommends that PY and PG antioxidants be used for safeguarding biodiesel fuel from the effects of autoxidation during storage.

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Mewa, Choonilall. "Quality assessment of frying oils in the formal and informal food preparation sectors." Thesis, 1998. http://hdl.handle.net/10321/1916.

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Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Chemical Sciences, Technikon Natal, 1998.
The demand for fried foods by the public and the number of people entering the fried food industry in the form of take-aways and fast food outlets both in the formal and informal sectors has increased tremendously. Frying fats and oils are very expensive, used in large quantities and is the most important ingredient used in the preparation of fried foods: Due to the high cost of these frying fats and oils, majority of the formal and informal traders are using the frying fats and oils to its maximum in order to reduce the overall cost. This has resulted in the preparation of poor quality offried foods. Considering all of the above, the aim of the proposed research was :- (a) to determine the quality of the frying fats and oils used by both the formal and informal sectors by performing both physical and chemical analyses and compare these with similar analyses performed on the unused frying fats and oils in order to ascertain the degree of deterioration of the used frying fats and oils (b) to investigate the method of disposal of the used frying fats and oils. (c) to contribute in educating both the consumers and the suppliers of fried foods by bringing the findings of this research to the attention of the Durban Metro Health Department. The used frying fats 'and oils were collected during the frying process by the environment health officer from the Durban Metro Health Department. These samples were placed in a refridgerator to prevent any further deterioration. The used and unused frying fats and oils were analysed for, the Free Fatty Acid and Acid Value contents; the quantitative separation of Monoglycerides, Diglycerides and Triglycerides; the Refractive Index; the Peroxide Values; the concentrations of Polar and Non-polar Compounds; the Viscosity and the identification of the various fatty acid methyl esters present in the samples. The analytical methods used were followed from the American Oil Chemists Society (AOCS) Official Method Handbook. The Free Fatty Acid and Acid Value results showed that twenty-five percent of the samples had a concentration of more than the maximum acceptable limit of 2.5%. It was evident that the types of food fried, the intermittent heating, frying
M

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Swalaha, Feroz Mahomed. "Optimization of riboflavin production by fungi on edible oil effluent." Thesis, 2010. http://hdl.handle.net/10321/552.

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Submitted in fulfilment for the requirements for the degree of Doctor of Technology: Biotechnology, Durban University of Technology, 2010.
South African edible oil processing plants produce approximately 3 x 105 tonnes of oil annually with up to 3 tonnes of water for every tonne of oil produced. Wastewater that contains oil extracts varies in organic loading from 30,000 to 60,000 mg.l-1 COD. This wastewater can be used to grow oleophilic fungi to produce valuable industrial products. The global vitamin B market is approximately R25.5 billion with 4500 metric tonnes being produced. A large proportion of this is produced using the fungus Eremothecium gossypii using oil substrates. The aim of this study was to to develop a novel method to produce riboflavin with the aid of fungi, using edible oil effluent (EOE) as substrate, and to optimize the production thereof by statistical experimental design. Four fungi were surveyed for their growth potential on EOE and two, E. gossypii (CBS109.51) and C. famata (ATCC 208.50) were found to produce sufficient riboflavin for further study. Mutation of these organisms using ethylmethane sulphonate (EMS) increased riboflavin production from 3.52 mg.l-1 to 38.98 mg.l-1, an 11-fold increase. An enzyme pathway responsible for this was found to involve isocitrate lyase and comparison of this enzyme’s activity in the mutant against the wild-type using Michaelis-Menten kinetics showed a higher reaction velocity (Vmax) with a reduced substrate affinity (Km) indicating that the mutation was associated with this enzyme. Biomass comparisons were fitted to the sigmoid Gompertz model which was used to compare the wild-type to the mutant and increased specific growth rates and doubling times were observed in mutated cultures of E. gossypi. A strategy of statistical experimental design was pursued to optimize media components and iterative fractional factorial experiments culminating in a central composite optimization experiment were conducted. Statistically verified mathematical models were developed at each stage to identify important media components, predict media interactions, show directions for improvement and finally, predict maximum riboflavin production. An eight-factor resolution IV fractional factorial increased riboflavin production to 112 mg.l-1 followed by a four-factor resolution V experimental design which increased riboflavin production to 123 mg.l-1. A two-factor (yeast extract and NaCl) central composite experimental design predicted a maximum riboflavin production of 136 mg.l-1 which was a 3.5-fold increase from the mutant, and 38.6-fold higher than the E. gossypii wild-type. The optimized value was achieved within predicted confidence intervals in confirmatory experiments. Cost implications for production of riboflavin on EOE were calculated and a 10% technology uptake by the edible oil industry could yield a riboflavin industry with a 63.65 million rand turnover and a potential 24.96 million rand gross profit margin.

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Tsai, Kwo-Liang, and 蔡國樑. "To Determine The Key Success Factors for The Edible Oils and Fats from Business Ecosystem Perspective." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/84857g.

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碩士
國立中興大學
高階經理人碩士在職專班
106
Business Ecosystem is one of the concepts of Ecological Systems. In the business ecosystem, enterprises cannot develop on their own. Only through cooperation and competition processes to create a market steady development.In this study, the definition of reference scholars, based on industrial practice experience, proposes a business ecosystem definition of the business oil industry: "For the independent individual enterprises that cross the industry, the economic scale is the basis of the competition of the dominant (Key person).The demand for innovation and diversification is less, however, they affect each other, also competition and cooperation. They have their own market mechanisms for regulating growth and decline, but they all aim at the common oil industry standards and interests." Therefore, the research explores direction of innovation products with added value and the circulation service innovation that attracts small wholesalers to suppliers'' warehousing and self-transportation. It is to find out the innovative development opportunities and the key factors affecting the success of the business oil ecosystem. This research method is for innovative product research interviewed 12 chains of food, grain wholesalers, modern logistics suppliers, and professional procurement and professional managers of cross-industry flour manufacturers to explore value-added innovative products in potential market and the key factors affecting.Circulation Innovation Research in the B2B organization procurement behavior, the supplier selection criteria are summarized into six criteria: product quality, price, service, corporate reputation, personnel professionalism, trust, and behavioral intentions are aggregated into seven facets, and questionnaire survey through the literature collection development questionnaire and GRA grey correlation analysis methods were used to explore the key factors affecting the participation of small wholesalers in the construction of warehouses. The results of this study are based on the theory of business ecosystems, which depicts the business ecosystem dominated by its own business, and through the systematic representation of the supply chain, to understand the roles and interactions of current members. Innovative product research, based on the results of qualitative interviews, summarizes three key issues. 1. Cost considerations 2. Niche market 3. End users cannot recognize the quality of oil products, and propose practices based on the experience of business oil industry as a new a reference for the development of product circulation models.In the study of warehousing and self-transportation mode, retrieve 114 questionnaires and 14 key factors were extracted from the seven facets by GRA gray correlation analysis. The recommended methods were also proposed. The factors are as follows: (1.) Key factors of product quality facet: product reputation, product quality, food safety certification. (2.) Key factors of price facet: ex-factory price, freight subsidy, and profit. (3.) Key factors of service facet: tally time and driving distance. (4.) Key factors of corporate reputation facet: supplier credit. (5.) Key factors of professional facet: personnel attitude and speed of personnel response. (6.) Key factors of trust facet: supplier reliability and supplier honesty. (7.) Behavioral intentional facet with construction factors: development of cooperative relations. This study introduces a new circulation marketing model of innovative products through the view of commercial ecosystem, replaces the traditional price competition promotion model, and shortens the communication distance with B2B customers, establishment of warehousing and self-transportation strategy to expand regional market and integrate marketing resources strengthen the value-added appeal and form an innovative business model of the new business ecosystem. It is expected to provide a new thinking model for the development opportunities of enterprise circulation innovation.

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Ainsworth, Sandra Denise. "Development of a predictive model for the enzymatic interesterification of edible fats and oils under solvent-free conditions." Thesis, 2001. https://vuir.vu.edu.au/30219/.

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The modification of the properties of fats and oils through enzymatic interesterification processes has great potential for industrial usage. The objective of this study was to investigate the process of enzymatic batch interesterification of edible fats and oils, under solvent-free conditions, and the development mathematical equations through modeling studies for predicting the outcomes of interesterification given specified reaction conditions. These modeling studies would provide industry with tools for optimising the enzymatic interesterification process and assist in producing tailor-made fats with specific physical properties.

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Song, Hae-Jin Chemical Sciences &amp Engineering Faculty of Engineering UNSW. "Gustatory effects of dietary fat." 2007. http://handle.unsw.edu.au/1959.4/40592.

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This thesis investigates whether fats, akin to other taste stimuli, exhibit sensory properties such as mixture interactions. In order to determine gustatory, rather than tactile or olfactory effects, viscosity-controlled emulsions of deodorised oils were used as the base to which taste stimuli were incorporated and presented to a panel of trained assessors. In preliminary qualitative assessments, panellists described the 10% olive oil emulsion as saltier, stronger, fattier and having a more lingering aftertaste than the non-oil control, suggesting that oil modulates taste duration as well influencing taste intensity and/or perceived quality. Panellists were unable to rate the oil/fat taste per se with any degree of certainty hence further experiments examined the effect of oil on the perception of taste mixtures. In mixture interaction experiments, the addition of oil did not result in mixture suppression or enhancement for sweet, salty, sour or bitter while it significantly enhanced umami. To determine the locus of interaction, when MSG and oil were presented to each side of the tongue separately, the enhancement effect disappeared indicating a peripheral mechanism of interaction, similar to the attenuation of chilli burn by oil. In contrast, suprathreshold sucrose sweetness was enhanced by the contralateral presentation of oil, indicating sensory processing at a higher locus. Furthermore, the addition of oil significantly reduced bitterness in a caffeine-MSG mixture. Since earlier experiments did not indicate any interaction between oil and bitterness, the decrease in the perceived bitterness of this binary mixture is attributed to an increase in umami which is likely to have suppressed bitterness, the perceptually dominant component in this mixture. These findings suggest a gustatory role for fats in modulating the taste profile of mixtures, in particular, enhancing total taste intensity, prolonging taste duration, and enhancing umami. A taste receptor-based model of fat perception provides for an orosensory mechanism capable of signalling the arrival of the most energy-dense nutrient, essential fatty acids and fat-soluble vitamins. The chemosensory signal may also be the basis for hedonic responses with subsequent implications for intake.

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Cole, Frank Arthur. "Bread staling: effects of fats, surfactants, storage time and storage temperature, and the interaction between these factors." 1985. http://hdl.handle.net/2097/27418.

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Kamm, Willibald [Verfasser]. "Authenticity control of edible fats and oils by analysis of minor constituents via on-line liquid chromatography - gas chromatography / Willibald Kamm." 2002. http://d-nb.info/965254364/34.

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Martin, Merrie Lyn. "Effect of soy flour on fat absorption by cake donuts." 1985. http://hdl.handle.net/2097/27492.

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Padayachee, Theresa. "Quality of deep fried chip cooking oil at fast food outlets in the South Central Operational Entity within Ethekwini Municipality." Thesis, 2006. http://hdl.handle.net/10413/7619.

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The demand for deep fried chips by public and the number of people entering the fast food industry in the form of fast food outlets has increased tremendously. Frying oils are very expensive and are the most important ingredient used in the preparation of fried foods. Due to high oil costs and lack of knowledge, frying oils are used to their maximum. This has resulted in the abuse of deep fried chip cooking oils. The overall quality of the deep fried chip cooking oil used in the South Central Operational Entity of the eThekwini Municipality is not known but abused cooking oils have been identified by Environmental Health Practitioners (EHP's) during routine inspections of fast food outlets. Considering all of the above, the objectives of the proposed research were: (l) Determine the overall prevalence of the use of abused deep fried chip cooking oils at fast food outlets in the South Central Operational Entity of the eThekwini Municipality. (2) Determine in which supervision areas in the South Central Operational Entity the use of abused cooking oil is most prevalent. (3) Determine current/reported practices in preserving the quality of chip oil. (4) Make appropriate recommendations to owner/managers of the fast food outlets and to Environmental Health Practitioners. The study design was observational utilizing a Rapid Epidemiological Assessment (REA) technique, with both a descriptive and analytical component. All fast food outlets making deep fried chips in the South Central Operational Entity registered with the eThekwini Health Department at the time of the study were included in the study population. The Lot Quality Assurance Sampling (LQAS) method was used to determine the overall prevalence of the use of abused oil and to determine supervision areas reached the predetermined service target. A total of 100 fast food outlets were sampled. An oil sample from each fast food outlet, which was taken and sent to a laboratory where an Oxifrit Test was done on every oil sample taken. The Oxifrit Test was the benchmark in this study. EHP's of eThekwini Municipality collected further data by means of an observational checklist and a closed-ended questionnaire, which aimed to establish cooking oil preservation practices. The study revealed that 60 of the outlets had oil that was acceptable whereas 40 had oil that was unacceptable (abused oil). In the multivariate analysis the only factors significantly associated with abused oil were the condition of the fryer and frequency of oil change. Supervision Areas 6, and 4 had more abused deep fried chip cooking oil than average in the South Central Operational Entity. For further prioritization, Supervision Areas 6 and 4 fell below the decision rule for majority of acceptable oil preservation practices, thus Supervision Areas 6 and 4 will be targeted for intervention. Intervention will include education, monitoring and ultimately enforcing the law by EHP's to ensure safe use of deep fried chip cooking oil in the South Central Operational Entity within eThekwini Municipality.
Thesis (M.P.H.)-University of KwaZulu-Natal, 2006.

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Van, Wormer Deborah M. "Effect of lecithin and source and level of fat in starter pig diets on performance and nutrient utilization." 1985. http://hdl.handle.net/2097/27567.

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Wiles, Nicola Laurelle. "The use and interpretation of the nutrition information on the food label of selected fat spreads by female consumers aged 25-45 years, living in Pietermaritzburg." Thesis, 2006. http://hdl.handle.net/10413/5334.

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Aim: To determine the use and interpretation of the nutrition information on the food label of selected fat spreads by female consumers aged 25 to 45 years, living in Pietermaritzburg. Objectives: This study set out to determine the following objectives regarding the food label: what the demographics of the consumers making use of the label were; how these consumers used the label and their motivation behind this label use and did the use of the label alter the purchase of that product? Method: One hundred and fifty women aged 25-45 years were chosen from an accidental, non-probability sample of consumers shopping at selected supermarkets within Pietermaritzburg. Respondents were presented with a four part questionnaire surrounding the purchase of selected fat spreads. Results: The greatest number of respondents were from the white population group (n = 65), followed by black respondents (n = 46), Indian respondents (n = 29) and then coloured respondents (n = 10). Results showed that the respondent who was most likely to use the nutrition information on the food label had a tertiary education; was a primary food purchaser, lived with other people, had more than R1000 a month to spend on food and was conscious of choosing the healthier option. Fifty five percent of this study sample (n = 82) claimed to use the nutrition information on the label to assist with purchases and 68% (n = 102) found the nutrition information important for purchasing a new product. Of the potential factors that have previously been found to impede the use of the nutrition information label:-inadequate print size, lack of education as well as lack of nutrition information on the food label were found to be factors restricting label use in this study. The most commonly used sources of nutrition information were the media as well as friends and family and the most trusted source was the Health Professional. Discussion: If the nutrition information is to be used both correctly and effectively, there must be a major educational campaign that sets out to meet the needs of the population that are most vulnerable, especially those with an inadequate education. Conclusion: The consumer most likely to use the nutrition information on the food label has a tertiary education, is a primary food purchaser with a large amount of money available for groceries and is conscious of choosing a healthier option. The label is most likely to be used when purchasing a fat spread for the first time.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

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Dissertations / Theses on the topic 'Oils and fats, Edible Oxidation'

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