Articoli di riviste: "Lactose hydrolysis"

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Xu, Yunli, Guowei Shu, Chunji Dai, Chun Yin, Xu Dong, Yuliang Guo e He Chen. "Screening of lactases suitable for the preparation of low-lactose prebiotic liquid milk and optimisation of their combination". Acta Universitatis Cibiniensis. Series E: Food Technology 25, n. 2 (1 dicembre 2021): 275–84. http://dx.doi.org/10.2478/aucft-2021-0025.

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Abstract Lactose intolerance is an important factor restricting the consumption of dairy products. Lactase is used to hydrolyze lactose in milk while generating galactooligosaccharides (GOS), thereby reducing the incidence of lactose intolerance. We used cow milk as raw materials, and selected enzyme preparations with high lactose hydrolysis rate and strong GOS generation ability from 14 commercially available lactase enzymes. The lactose hydrolysis rate is 5.85%-81.38%, and the GOS content is 0.03 g/L- 13.10 g/L. The mixing experiment design determined the two lactase enzymes (E10 and E11) ratio and the optimal enzymatic hydrolysis process of low-lactose prebiotic milk: compound lactases (E10:E11=0.756:0.244) addition 0.11%, 55℃for 5h, lactose hydrolysis rate and GOS content were 98.02% and 19.69g/L, respectively, and the remaining lactose content was about 0.97 g/L.

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Rao, D. R., e C. B. Chawan. "Enzyme technologies for alleviating lactose maldigestion / Tecnologías enzimáticas para aliviar la mala digestion de la lactosa". Food Science and Technology International 3, n. 2 (aprile 1997): 81–86. http://dx.doi.org/10.1177/108201329700300202.

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Lactose reduction in milk by β-galactosidase prior to consumption is one of the current modali ties of alleviating lactose maldigestion. However, hydrolysis of lactose results in flavour changes in milk: glucose and galactose are between three and four times sweeter than lactose, and many lactose maldigesters do not like the taste of lactose-hydrolysed milk. The addition of exogenous β-galactosidase to meals has been shown to alleviate lactose maldigestion adequately, and so β-galactosidase could be added to milk if the lactose could be protected from the hydrolytic action of the added enzyme. Liposomes, which have recently shown potential as carriers of enzymes, could be good vehicles for the addition of β-galactosidase to milk. β-galactosidase can be successfully encapsulated in liposomes which have been shown to be very stable when suspended in milk stored at refrigeration temperature. Lactose hydrolysis is minimal when liposomal β-galactosidase is added to milk. In vitro digestibility studies have shown that the liposomal β-galactosidase is available for digesting lactose in milk. Stable blends of β-galactosidase and dry milk powders have also been used. Results have shown that up to 95% of the original activity of the fungal lactase was retained in blends of the enzyme and milk powder when stored under nitrogen at 45 °C for 6 months.

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Zhao, Di, Thao T. Le, Lotte Bach Larsen, Yingqun Nian, Cong Wang, Chunbao Li e Guanghong Zhou. "Interplay between Residual Protease Activity in Commercial Lactases and the Subsequent Digestibility of β-Casein in a Model System". Molecules 24, n. 16 (8 agosto 2019): 2876. http://dx.doi.org/10.3390/molecules24162876.

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One of the conventional ways to produce lactose-hydrolyzed (LH) milk is via the addition of commercial lactases into heat-treated milk in which lactose is hydrolyzed throughout storage. This post-hydrolysis method can induce proteolysis in milk proteins due to protease impurities remaining in commercial lactase preparations. In this work, the interplay between lactose hydrolysis, proteolysis, and glycation was studied in a model system of purified β-casein (β-CN), lactose, and lactases using peptidomic methods. With a lactase presence, the proteolysis of β-CN was found to be increased during storage. The protease side-activities mainly acted on the hydrophobic C-terminus of β-CN at Ala, Pro, Ile, Phe, Leu, Lys, Gln, and Tyr positions, resulting in the formation of peptides, some of which were N-terminal glycated or potentially bitter. The proteolysis in β-CN incubated with a lactase was shown to act as a kind of “pre-digestion”, thus increasing the subsequent in vitro digestibility of β-CN and drastically changing the peptide profiles of the in vitro digests. This model study provides a better understanding of how the residual proteases in commercial lactase preparations affect the quality and nutritional aspects of β-CN itself and could be related to its behavior in LH milk.

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Majore, Kristine, e Inga Ciprovica. "Sensory Assessment of Bi-Enzymatic-Treated Glucose-Galactose Syrup". Fermentation 9, n. 2 (31 gennaio 2023): 136. http://dx.doi.org/10.3390/fermentation9020136.

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There are a variety of ways to make glucose-galactose syrup (GGS) and other products of lactose hydrolysis; therefore, research is still ongoing and will undoubtedly result in improved methods and lower costs. The aim of the study was to use a two-stage fermentation approach to increase the sweetness of glucose-galactose syrup. Comparing lactose hydrolysis with β-galactosidases, the enzyme Ha-Lactase 5200 (K. lactis) showed the highest hydrolysis yield but NOLA™ Fit5500 (B. licheniformis) and GODO-YNL2 (K. lactis) hydrolysis yields varied. After the two-stage fermentation, the syrups from sweet whey permeate had shown the highest sweet taste intensity scores; the sweetest samples were 1NFS and 1HLS with a score of 9.2 and 9.3, respectively. The presence of fructose in the range of 14 ± 3 to 25 ± 1 %, significantly (p < 0.05) increased the sweetness of the syrups. Obtained syrups from whey permeates using enzymes NOLA™ Fit5500 and Ha-Lactase 5200 contained less than 10% lactose. Additionally, results indicate that hydrolysis of lactose and subsequent enhancement of sweetness through glucose isomerisation may provide additional benefits through the production of galacto-oligosaccharides (GOS) in the range of 2 ± 1 to 34 ± 7%.

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Costa, Cleiver Júnio Martins, Camila Alves Moreira, Ricardo Corrêa de Santana, Amado Jésus Silva, Juliana Karla de Souza Teixeira Almeida e Milla Gabriela dos Santos. "Lactose quantification in UHT milk by high-performance liquid chromatography and cryoscopy (freezing point depression)". Research, Society and Development 10, n. 15 (23 novembre 2021): e454101523224. http://dx.doi.org/10.33448/rsd-v10i15.23224.

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Due to the large number of people with lactose maldigestion, the dairy industries have increased production and diversity of low lactose and lactose-free foods. Consequently, the need to control the lactose hydrolysis process has also risen. This study aimed to correlate freezing point depression (cryoscopy) and lactose concentration, quantified by high-performance liquid chromatography (HPLC), in UHT milk. To accomplish this, UHT milk samples were subjected to seven lactose hydrolysis treatments, using lactase enzyme, resulting in different lactose concentrations. All samples were subjected to HPLC analysis and freezing point measurement, using a cryoscope. The results were plotted on a graph and a linear regression was performed. There was a strong correlation between lactose concentration and freezing point (R = 0,9973) and the coefficient of determination (R2) was 0,9946, which means that 99,46% of the variability of the response data is explained by the linear regression model. Therefore, the results point to the feasibility of estimating the lactose concentration in milk during the hydrolysis process for the production of low lactose milk, by cryoscopy, a quick analysis, with lower cost compared to HPLC and that is already among the analyses commonly performed in dairy industries.

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Buller, H. A., A. G. Van Wassenaer, S. Raghavan, R. K. Montgomery, M. A. Sybicki e R. J. Grand. "New insights into lactase and glycosylceramidase activities of rat lactase-phlorizin hydrolase". American Journal of Physiology-Gastrointestinal and Liver Physiology 257, n. 4 (1 ottobre 1989): G616—G623. http://dx.doi.org/10.1152/ajpgi.1989.257.4.g616.

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Lactase-phlorizin hydrolase, a small intestinal disaccharidase, has been considered mainly an enzyme important only for the hydrolysis of lactose. After weaning in most mammals lactase-specific activity falls markedly, and, functionally, adult mammals are considered to be lactase deficient. However, the persistence of low levels of lactase activity in adulthood has never been explained. In addition, it has been suggested that lactase-phlorizin hydrolase is associated with glycosylceramidase activity when the enzyme is prepared by column chromatography, but it is unclear whether this represents copurified activities or two catalytic sites on one peptide. The developmental patterns of lactase-phlorizin hydrolase and other disaccharidases were investigated in homogenates of total rat small intestine; lactase and several glycosylceramidases were measured in immunoprecipitates from these homogenates using a monoclonal antibody. The developmental pattern of total lactase activity showed a steady 2.3-fold increase to adult levels (specific activity decreased eightfold), whereas total phlorizin-hydrolase activity increased 10.7-fold (specific activity decreased threefold). As expected, levels of both total and specific sucrase and maltase activities increased during development. In lactating rats total lactase activity showed a significant increase compared with adult males. The developmental pattern of the enzyme activities for the glycolipid substrates was similar to that found for lactase, and the immunoprecipitated enzyme showed a 40- to 55-fold higher affinity for the glycolipids than for lactose. Galactosyl- and lactosylceramide inhibited lactose hydrolysis by 38%, without a competitive pattern, suggesting two different active sites for lactose and glycolipid hydrolysis, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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Høyvik, H., P. B. Gordon, T. O. Berg, P. E. Strømhaug e P. O. Seglen. "Inhibition of autophagic-lysosomal delivery and autophagic lactolysis by asparagine." Journal of Cell Biology 113, n. 6 (15 giugno 1991): 1305–12. http://dx.doi.org/10.1083/jcb.113.6.1305.

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Overall autophagy was measured in isolated hepatocytes as the sequestration and lysosomal hydrolysis of electroinjected [14C]lactose, using HPLC to separate the degradation product [14C]glucose from undegraded lactose. In addition, the sequestration step was measured separately as the transfer from cytosol to sedimentable cell structures of electroinjected [3H]raffinose or endogenous lactate dehydrogenase (LDH; in the presence of leupeptin to inhibit lysosomal proteolysis). Inhibitor effects at postsequestrational steps could be detected as the accumulation of autophaged lactose (which otherwise is degraded intralysosomally), or of LDH in the absence of leupeptin. Asparagine, previously shown to inhibit autophagic but not endocytic protein breakdown, strongly suppressed the autophagic hydrolysis of electroinjected lactose. Vinblastine, which inhibits both types of degradation, likewise suppressed lactose hydrolysis. Asparagine had little or no effect on sequestration, but caused an accumulation of autophaged LDH and lactose, indicating inhibition at a postsequestrational step. Neither asparagine nor vinblastine affected the degradation of intralysosomal lactose preaccumulated in the presence of the reversible lysosome inhibitor propylamine. However, if lactose was preaccumulated in the presence of asparagine, both asparagine and vinblastine suppressed its subsequent degradation. The data thus indicate that autophagic-lysosomal delivery, i.e., the transfer of autophaged material from prelysosomal vacuoles to lysosomes, is inhibited selectively by asparagine and non-selectively by vinblastine.

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Hanauer, Duana Ceciliane, e Alexandre Tadeu Paulino. "Anchoring lactase in pectin-based hydrogels for lactose hydrolysis reactions". Process Biochemistry 122 (novembre 2022): 50–59. http://dx.doi.org/10.1016/j.procbio.2022.08.026.

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Renner, E. "Dietary approaches to alleviation of lactose maldigestion / Efectos de la dieta sobre la digestión de la lactosa". Food Science and Technology International 3, n. 2 (aprile 1997): 71–79. http://dx.doi.org/10.1177/108201329700300201.

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Because dairy products are a significant source of essential nutrients, elimination of all dairy foods in the diet would be nutritionally unwise and is usually not necessary in the case of lactose maldigestion. About 250 ml milk/d can generally be taken without adverse effects. If milk is taken in combination with solid foods, lactose malabsorption may be reduced by about 50%, probably due to a slower rate of colonic fermentation which may lower gastrointestinal symptoms in lactose malabsorbers. It is well established that, in lactase-deficient subjects, yoghurt is better tolerated than milk. This is only to some extent related to the fact that the lactose content of the products is reduced during fermentation, but is mainly attributed to the fact that the culture organisms- by virtue of being rich in lactase - are able to participate in the hydrolysis of ingested lactose. Up to 20 g of lactose in yoghurt is tolerated well by lactase-deficient persons. The enhanced absorp tion of lactose in yoghurt is explained as a result of the intestinal release of lactase from the yoghurt organisms. Ripened cheese is also tolerated very well by lactose-intolerant persons since virtually all of the lactose present is decomposed to lactic acid and other metabolites.

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Czyzewska, Katarzyna, e Anna Trusek. "Encapsulated NOLA™ Fit 5500 Lactase—An Economically Beneficial Way to Obtain Lactose-Free Milk at Low Temperature". Catalysts 11, n. 5 (21 aprile 2021): 527. http://dx.doi.org/10.3390/catal11050527.

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The current requirements of industrial biocatalysis are related to economically beneficial and environmentally friendly processes. Such a strategy engages low-temperature reactions. The presented approach is essential, especially in food processes, where temperature affects the quality and nutritional value foodstuffs. The subject of the study is the hydrolysis of lactose with the commercial lactase NOLA™ Fit 5500 (NOLA). The complete decomposition of lactose into two monosaccharides gives a sweeter product, recommended for lactose intolerant people and those controlling a product’s caloric content. The hydrolysis reaction was performed at 15 °C, which is related to milk transportation and storage temperature. The enzyme showed activity over the entire range of substrate concentrations (up to 55 g/L lactose). For reusability and easy isolation, the enzyme was encapsulated in a sodium alginate network. Its stability allows carrying out six cycles of the complete hydrolysis of lactose to monosaccharides, lasting from two to four hours. During the study, the kinetic description of native and encapsulated NOLA was conducted. As a result, the model of competitive galactose inhibition and glucose mixed influence (competitive inhibition and activation) was proposed. The capsule size does not influence the reaction rate; thus, the substrate diffusion into capsules can be omitted from the process description. The prepared 4 mm capsules are easy to separate between cycles, e.g., using sieves.

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Yang, Zhennai, Eero Pahkala e Tuomo Tupasela. "Lactose hydrolysis by free and fibre-entrapped β-galactosidase from Streptococcus thermophilus". Agricultural and Food Science 2, n. 5 (1 settembre 1993): 395–401. http://dx.doi.org/10.23986/afsci.72665.

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To study lactose hydrolysis by β-galactosidase, this enzyme was produced from Streptococcus thermophilus strain 11F and partially purified by acetone and ammonium sulphate fractionation, and ion exchange chromatography on a Q Sepharose FF column. Lactose hydrolysis by the enzyme was affected by lactose concentrations, sugars and milk proteins. The maximum extent of lactose hydrolysis in buffer was obtained with a 15% lactose concentration. Addition of 2% of lactose, glucose, galactose or sucrose in milk inhibited the enzymatic hydrolysis. The enzyme was activated by bovine serum albumin and a combination of αs-casein and β-casein. Of the casein fractions, the principal fraction, αs-casein, was less effective than β-casein and κ-casein. The fibre entrapped enzyme had a temperature optimum of 57°C, and a pH optimum from 7.5 to at least 9.0 with O-nitrophenyl-β-D-galactopyranoside as substrate. By recycling with whey and skim milk through a jacketed glass column (1.6 cm x 30 cm) loaded with fibre-entrapped enzyme at 55°C, a lactose hydrolysis of 49.5% and 47.9% was achieved in 11 h and 7 h respectively.

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Popescu, Liliana, Viorica Bulgaru e Rodica Siminiuc. "EFFECTS OF LACTOSE HYDROLYSIS AND MILK TYPE ON THE QUALITY OF LACTOSE-FREE YOGHURT". Journal of Engineering Science 29, n. 4 (gennaio 2023): 164–75. http://dx.doi.org/10.52326/jes.utm.2022.29(4).13.

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The purpose of the work was to investigate the influence of different lactose hydrolysis processes, the contribution of the enzyme and the milk type on the characteristics of the obtained lactose-free yogurt. The analysis was performed on non-hydrolyzed yogurt (control sample), the pre-hydrolyzed yogurt (that was hydrolyzed before fermentation), and the co-hydrolyzed yogurt (concurrent addition of β-galactosidase and starter culture). According to the obtained results, at the end of the fermentation time, an advanced hydrolysis degree was reached (over 80%) both for yogurt samples obtained from pre-hydrolyzed milk and obtained by co-hydrolysis. The optimal method from the economic point of view is to obtain yogurt by co-hydrolysis. The sensory quality of the yogurt samples obtained from hydrolyzed milk by co-hydrolysis was characterized by a better flavor than the control sample, for yogurt from both types of milk. This may be due to the availability of a greater amount of glucose for the production of aromatic compounds, a sweeter taste than natural yogurt, with a light caramel flavor, a firm coagulum, a porcelain appearance, without whey removal. Cow’s milk yogurt showed higher viscosity values to goat’s milk yogurt for both pre-hydrolyzed and co-hydrolyzed milk. Lactose hydrolysis determined the reduction of the syneresis index of the yogurt compared to the control samples. The studies led to the development of lactose-free yogurt with improved sensory and rheological properties recommended for people with lactose intolerance.

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Lindsay, Mark J., Theodore W. Walker, James A. Dumesic, Scott A. Rankin e George W. Huber. "Production of monosaccharides and whey protein from acid whey waste streams in the dairy industry". Green Chemistry 20, n. 8 (2018): 1824–34. http://dx.doi.org/10.1039/c8gc00517f.

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Cruz, Rubens, Vinícius D'Arcádia Cruz, Juliana Gisele Belote, Marcelo de Oliveira Khenayfes, Claudia Dorta e Luiza Helena dos Santos Oliveira. "Properties of a new fungal b-galactosidase with potential application in the dairy industry". Revista de Microbiologia 30, n. 3 (luglio 1999): 265–71. http://dx.doi.org/10.1590/s0001-37141999000300014.

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b-Galactosidase or b-D-galactoside-galactohydrolase (EC. 3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for the synthesis of transgalactosylated oligosaccharides (TOS) that act as functional foods, with several beneficial effects on consumers. Penicillium simplicissimum, a strain isolated from soil, when grown in semi-solid medium showed good productivity of b-galactosidase with galactosyltransferase activity. The optimum pH for hydrolysis was in the 4.04.6 range and the optimum pH for galactosyltransferase activity was in the 6.07.0 range. The optimum temperature for hydrolysis and transferase activity was 55-60°C and 50°C, respectively, and the enzyme showed high thermostability for the hydrolytic activity. The enzyme showed a potential for several industrial applications such as removal of 67% of the lactose from milk and 84% of the lactose from milk whey when incubated at their original pH (4.5 and 6.34, respectively) under optimum temperature conditions. When incubated with a 40% lactose solution in 150 mM McIlvaine buffer, pH 4.5, at 55°C the enzyme converted 86.5% of the lactose to its component monosaccharides. When incubated with a 60% lactose solution in the same buffer but at pH 6.5 and 50°C, the enzyme can synthetize up to 30.5% TOS, with 39.5% lactose and 30% monosaccharides remaining in the preparation.

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Tsuchiya, Ana Claudia, Ana Da Graça Monteiro da Silva, Daniela Brandt, Daneysa Lahis Kalschne, Deisy Alessandra Drunkler e Eliane Colla. "Lactose reduced ice cream enriched with whey powder". Semina: Ciências Agrárias 38, n. 2 (2 maggio 2017): 749. http://dx.doi.org/10.5433/1679-0359.2017v38n2p749.

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Ice cream is a food product that pleases the palate of consumers worldwide. Whey powder (WP) has various technological and functional properties. However, WP increases the lactose content of the final products in which it is incorporated and causes grittiness and intolerance in lactose-sensitive individuals. This study aimed to produce ice cream with milk powder (MP) replaced by WP (MP/WP), decrease the lactose content by enzymatic hydrolysis and verify the physicochemical and microbiological parameters of the final product. Initially, the variables ?-galactosidase concentration and reaction time were studied for the response of the percentage of lactose hydrolysis in a milk ice cream base, using a full 22 factorial design(FFD).With the reaction conditions defined (0.5 g L-1 of ?-galactosidase at 37 C for 4 h)the sucrose concentration and MP/WP replacement variables were then studied in the ice cream formulation for the percentage of lactose hydrolysis and overrun responses using a 22 FFD. The lactose hydrolysis, which ranged between 86.59-97.97%, was not affected by the MP/WP replacement in the ice cream, whilst the overrun was increased by the MP/WP replacement. The physicochemical and microbiological parameters of the ice cream were either not influenced or positively influenced by lactose hydrolysis and MP/WP replacement.

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Demirhan, Elçin, Dilek Kiliç Apar e Belma Özbek. "PRODUCT INHIBITION OF WHEY LACTOSE HYDROLYSIS". Chemical Engineering Communications 195, n. 3 (18 dicembre 2007): 293–304. http://dx.doi.org/10.1080/00986440701554863.

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Dutra Rosolen, Michele, Adriano Gennari, Giandra Volpato e Claucia Fernanda Volken de Souza. "Lactose Hydrolysis in Milk and Dairy Whey Using Microbial β-Galactosidases". Enzyme Research 2015 (26 ottobre 2015): 1–7. http://dx.doi.org/10.1155/2015/806240.

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This work aimed at evaluating the influence of enzyme concentration, temperature, and reaction time in the lactose hydrolysis process in milk, cheese whey, and whey permeate, using two commercial β-galactosidases of microbial origins. We used Aspergillus oryzae (at temperatures of 10 and 55°C) and Kluyveromyces lactis (at temperatures of 10 and 37°C) β-galactosidases, both in 3, 6, and 9 U/mL concentrations. In the temperature of 10°C, the K. lactis β-galactosidase enzyme is more efficient in the milk, cheese whey, and whey permeate lactose hydrolysis when compared to A. oryzae. However, in the enzyme reaction time and concentration conditions evaluated, 100% lactose hydrolysis was not reached using the K. lactis β-galactosidase. The total lactose hydrolysis in whey and permeate was obtained with the A. oryzae enzyme, when using its optimum temperature (55°C), at the end of a 12 h reaction, regardless of the enzyme concentration used. For the lactose present in milk, this result occurred in the concentrations of 6 and 9 U/mL, with the same time and temperature conditions. The studied parameters in the lactose enzymatic hydrolysis are critical for enabling the application of β-galactosidases in the food industry.

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Hegar, Badriul, e Hans A. Buller. "Breath Hydrogen Test in Lactose Malabsorption". Paediatrica Indonesiana 35, n. 7-8 (8 ottobre 2018): 161–71. http://dx.doi.org/10.14238/pi35.7-8.1995.161-71.

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Lactose is the most important source in mammalian milk. In normal children, Lactose is hydrolyzed by lactase, and directly absorbed into bloodstream by an active transport mechanism. The term of lactose malabsorption is reserved to patients in whom impaired intestinal lactose hydrolysis and uptake has been proven by an appropriate test. The severity of lactose malabsorption and the extent of symptoms vary widely and are the results of several factors such as the amount of ingested lactose, gastric emptying time, intestinal transit time, and colonic flora. The diagnosis of lactose malabsorption is based on clinical findings and the results of appropriate tests. The breath hydrogen test has obvious advantages for pediatric population because it is painless, non-invasive, sensitive and specific. In the absence of bacterial colonization in the small intestine, the elevation of the concentration of hydrogen in the expired air implies the arrival of lactose in the colon. The increasing respiratory excretion of hydrogen is indicative of a deficit of lactase in enterocyte brush border. This test can also be used to show the existence of bacterial growth. Dietary fiber, some drugs, preparation for colonoscopy, colonic pH, and diarrhea can influence the result of breath hydrogen test.

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Gorbunova, E. M., I. V. Kuznetsova, L. V. Lygina, S. E. Plotnikova, A. A. Tolkacheva e S. I. Niftaliev. "Synthesis of tagatose and fucose from dairy raw material". IOP Conference Series: Earth and Environmental Science 1052, n. 1 (1 luglio 2022): 012095. http://dx.doi.org/10.1088/1755-1315/1052/1/012095.

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Abstract Innovative biochemical technologies have been developed for obtaining a fucose-containing carbohydrate complex and a tagatose-containing sweetener from the secondary dairy raw material, lactose. A method for the production of tagatose has been tested, including the enzymatic treatment of lactose Lactozym 6500 L Pure at pH = 6.2 for 4.5 hours and an enzyme dosage of 7500 LAU/dm3. The kinetic parameters of lactose hydrolysis were calculated: maximum rate and order of the chemical reaction (V max = 1.08 ⋅ 10-5, n = 0.6967). The qualitative and quantitative parameters of lactose hydrolysis and isomerization of galactose into tagatose, obtained by HPLC, are presented. The degree of lactose hydrolysis is 92%; the tagatose yield is 41%. A method for the production of fucose from lactose with subsequent conversion of galactose into fucitol and enzymatic isomerization into fucose is proposed. The fucose yield is 42.5% of the total solid mass.

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Nilsson, U., e M. Jägerstad. "Hydrolysis of lactitol, maltitol and Palatinit® by human intestinal biopsies". British Journal of Nutrition 58, n. 2 (settembre 1987): 199–206. http://dx.doi.org/10.1079/bjn19870087.

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1. The hydrolysis of sugar alcohols of the disaccharide type such as lactitol, maltitol and Palatinit® (the latter an equimolar mixture of 6-O-α-D-glucopyranoside-D-mannitol and 6-O-α-D-glucopyranoside-D-sorbitol) by homogenates of human intestinal biopsies were compared with corresponding natural disaccharides such as lactose, maltose and isomaltose. Seven of the human biopsies were normal with regard to their disaccharidase activities, while twelve biopsies showed decreased levels of disaccharidase activities.2. All biopsies, normal as well as abnormal, showed essentially the same capacity to hydrolyse the sugar alcohols. Activities towards lactitol (0.34 IE/g protein (where IE = μmol disaccharide hydrolysed/min at 37°)) and Palatinit (2.50 IE/g protein) were only 1.3% of those towards lactose and isomaltose. The activity towards maltitol was much higher (19.1 IE/g protein), approximately 10% of that towards maltose and about as high as the activity towards trehalose. This finding indicates that despite the fact that lactitol and Palatinit were poor substrates, significant amounts of ingested maltitol might be digested and utilized by man.3. Glucose release was reduced by approximately 25% when maltitol or Palatinit were present at concentrations equal to those of maltose. Palatinit decreased the hydrolysis of sucrose by 12%. Lactitol had no inhibitory effect on the hydrolysis of disaccharides.

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Liburdi, Katia, e Marco Esti. "Galacto-Oligosaccharide (GOS) Synthesis during Enzymatic Lactose-Free Milk Production: State of the Art and Emerging Opportunities". Beverages 8, n. 2 (2 aprile 2022): 21. http://dx.doi.org/10.3390/beverages8020021.

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Much attention has recently been paid to β-Galactosidases (β-D-galactoside galactohidrolase; EC 3.2.1.23), commonly known as lactases, due to the lactose intolerance of the human population and the importance of dairy products in the human diet. This enzyme, produced by microorganisms, is being used in the dairy industry for hydrolyzing the lactose found in milk to produce lactose-free milk (LFM). Conventionally, β-galactosidases catalyze the hydrolysis of lactose to produce glucose and galactose in LFM; however, they can also catalyze transgalactosylation reactions that produce a wide range of galactooligosaccharides (GOS), which are functional prebiotic molecules that confer health benefits to human health. In this field, different works aims to identify novel microbial sources of β-galactosidase for removing lactose from milk with the relative GOS production. Lactase extracted from thermophilic microorganisms seems to be more suitable for the transgalactosylation process at relatively high temperatures, as it inhibits microbial contamination. Different immobilization methods, such as adsorption, covalent attachment, chemical aggregation, entrapment and micro-encapsulation, have been used to synthesize lactose-derived oligosaccharides with immobilized β-galactosidases. In this mini-review, particular emphasis has been given to the immobilization techniques and bioreactor configurations developed for GOS synthesis in milk, in order to provide a more detailed overview of the biocatalytic production of milk oligosaccharides at industrial level.

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GRIFFITH, LEE, ERIC SIGVALDSON e PETER SPORNS. "Determination of Lactose and Lactose Hydrolysis in Milk Using Cerium(IV)". Journal of Food Science 54, n. 2 (marzo 1989): 419–22. http://dx.doi.org/10.1111/j.1365-2621.1989.tb03097.x.

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Bogdanova, N. M., A. I. Khavkin e O. L. Kolobova. "Prospects of fermented milk products in children with primary hypolactasia of the adult type". Rossiyskiy Vestnik Perinatologii i Pediatrii (Russian Bulletin of Perinatology and Pediatrics) 65, n. 3 (8 luglio 2020): 160–68. http://dx.doi.org/10.21508/1027-4065-2020-65-3-160-168.

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Abstract (sommario):

Lactose (β-galactosyl-1,4 glucose) is milk sugar, the main disaccharide of human and other mammalian breast milk. Lactase is intestinal disaccharidase that catalyzes the lactose hydrolysis. The lactase gene LCT controls biological function of the enzyme. The age-related genetically determined feature of disaccharide expression, epigenetic factors, and natural selection with persistent tolerance to milk sugar throughout lifetime has divided the human population according to the LCT gene into two phenotypes: lactase persistent and lactase non-persistent. There is conflicting evidence that the latter phenotype is associated with low calcium absorption and the development of osteoporosis. The regular use of fermented probiotic dairy products by individuals with the lactase non-persistence phenotype ensures the accumulation of peak bone mineralization and prevents osteoporosis.

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24

Majore, Kristīne, e Inga Ciproviča. "Optimisation of Lactose Hydrolysis by Combining Solids and ß-Galactosidase Concentrations in Whey Permeates". Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 74, n. 4 (1 agosto 2020): 263–69. http://dx.doi.org/10.2478/prolas-2020-0041.

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AbstractA detailed study of lactose hydrolysis was conducted using 50, 250 and 500 units of ß-galactosidase (Kluyveromyces lactis and Bacillus licheniformis origin) in acid and sweet whey permeates at different solid concentrations 20%, 30% and 40% (w·v−1). The amount of lactose, glucose and galactose was measured by HPLC – RID. Hydrolysis was carried out at optimal enzyme temperature 42.5 °C for 4 h. Medium pH before hydrolysis was adjusted using 10% KOH. The experimental results were compared taking into account the sugar profiles and experimental conditions. The highest lactose hydrolysis occurred at solid concentration 20% (w·v−1) and at enzyme amounts of 250 and 500 units for both permeates. Using 50 units of enzymes, in many cases the amounts of glucose and galactose were more or less equal in range of 6.5–43 g·l−1 and the hydrolysis percentage was quite low in the range of 2.7–62%. Comparing both whey permeates, a higher hydrolysis percentage (99%) was obtained using acid whey and 500 enzyme units.

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25

Benbouziane, Bouasria, Mohamed-ChÃ©rif Bentahar, Hayet Takarly e Ben Mehel Benakriche. "Comparative study of two lactases by K-Lolac enzymatic method in skimmed milk". South Asian Journal of Experimental Biology 9, n. 1 (30 agosto 2019): 01–06. http://dx.doi.org/10.38150/sajeb.9(1).p01-06.

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Abstract (sommario):

Lactose absorption at the level of the small intestine depends on its hydrolysis by β-galactosidase. The activity of this enzyme, which gets to the peak at the beginning and halflife, decreases progressively after weaning. This activity loss (hypolactasie) is a physiological phenomenon observed in 70 to 75% of the world’s population. Hypolactasy is transmited according to an autosomal recessive mode to an incomplete penetrance and is linked to polymorphosis located in the promoter region of the gene coding the lactase. A solution is proposed regarding ingestion of dairy dislactosed products or products with unduly low lactose rates. In this study, two different enzymes were used, a β-galactosidase of Bifidobacterium [β-gal Bb] source and another β-galactosidase of Kluyveromyces lactis [β-gal Kl] source with different concentrations on lactose degradation in a preparation based on skimmed milk at 4° C during 18h with a 39 g/l lactose rate. Determining hydrolysis rate in lactose was achieved with an enzymatic method using a Megazyme K-lolac kit. The results demonstrated that β-gal Kl (Maxilat) in a 100 µl/L dose gives an optimal performance as compared to β-gal Bb (Nola fit) in residual lactose concentrations 1.85 g/L and 2.78 g/L respectively. However, in a dose that was superior to 1500 and 2000, the β-gal Bb was significantly more performing than β-gal Kl. To sum up, the enzymatic method used to define the residual lactose rate, the kit KLolac, gives very reliable results with a low threshold (LOD 1.62 mg/L).

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26

SCHMIDT, RONALD H., DAVID E. SMITH, VERNAL S. PACKARD e HOWARD A. MORRIS. "Compositional and Selected Functional Properties of Whey Protein Concentrates and Lactose-Hydrolyzed Whey Protein Concentrates1". Journal of Food Protection 49, n. 3 (1 marzo 1986): 192–95. http://dx.doi.org/10.4315/0362-028x-49.3.192.

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Abstract (sommario):

Commercial whey protein concentrate (WPC) products, manufactured by ultrafiltration with and without lactose hydrolysis, were compared for proximate composition, mineral and trace mineral composition and for protein solubility and viscosity parameters. Protein concentration ranged from 30.5 to 52.7%, while ash content ranged from 5.9 to 12.0%. Extent of lactose hydrolysis in lactose-hydrolyzed WPCs was estimated at 60 to 75% of the initial lactose level. Protein solubility of 10% protein dispersions of the WPC samples ranged from 90 to 100% and was not affected by heating WPC dispersions at 65°C for 30 min or by increased centrifugation force in solubility determination from 40,000 × g to 100,000 × g. All WPC dispersions exhibited pseudoplastic flow behavior as indicated by flow behavior indices (n) of less than 1.0. WPC dispersions possessed a low viscosity as indicated by consistency index (k) data, and k values decreased slightly after heating. Lactose hydrolysis had no apparent effect on solubility or viscosity properties of the WPC dispersions. Alteration of electrophoretic mobility of polyacrylamide gel electrophoresis was observed for α-lactalbumin in lactose-hydrolyzed WPC samples.

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27

Антипова, Татьяна Алексеевна, Светлана Валерьевна Фелик, Надежда Леонидовна Андросова e Сергей Владимирович Симоненко. "Preparation of low-lactose fermented milk products for baby food". Food processing industry, n. 6 (7 giugno 2021): 23–26. http://dx.doi.org/10.52653/ppi.2021.6.6.001.

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Статья посвящена получению кисломолочного продукта для питания детей с лактазной недостаточностью. Одним из наиболее распространенных способов получения низколактозных продуктов является применение гидролиза лактозы с использованием ферментных препаратов. Целью работы было изучение процесса сквашивания низколактозного молочного продукта. Учитывая, что при использовании методов ферментирования лактозы продукт приобретает выраженный сладкий вкус, обусловленный наличием глюкозы, требовалось установить заданное количество лактозы при достижении оптимальных органолептических показателей. Результаты исследований свидетельствуют об изменении органолептических и физико-химических показателей образцов в результате гидролиза лактозы. Вкусовые проявления сладости в продукте появляются при степени гидролиза лактозы 50 % и усиливаются при дальнейшем проведении гидролиза. Для проведения процесса сквашивания применяли следующие виды заквасочных культур: Lactobacillus acidophilus, Treptococcus thermophilus, Lactobacillus bulgaricus, Streptococcus thermophiles, Lactococcus lactis subsp. lactis и Lactococcus lactis subsp. Сremoris. Процесс сквашивания во всех образцах низколактозного молока имеет свои особенности, характерные для используемой заквасочной культуры. Следует отметить, что заквасочные культуры, включающие ацидофильную палочку, интенсифицируют процесс сквашивания исследуемых образцов. Содержание лактозы после окончания процесса сквашивания в исследуемых образцах составило 1,35; 1,4 %, что соответствует требованиям ТР ТС 027/2012 «О безопасности отдельных видов специализированной пищевой продукции, в том числе диетического лечебного и диетического профилактического питания». The article is devoted to the preparation of a fermented milk product for the nutrition of children with lactase deficiency. One of the most common methods of obtaining low-lactose products is the use of lactose hydrolysis using enzyme preparations. The aim of the work was to study the process of fermentation of low-lactose dairy product. Given that when using the methods of lactose fermentation, the product acquires a pronounced sweet taste due to the presence of glucose, it was necessary to set a given amount of lactose when achieving optimal organoleptic parameters. The results of the studies indicate a change in the organoleptic and physico-chemical parameters of the samples as a result of lactose hydrolysis. The taste manifestations of sweetness in the product appear at the degree of lactose hydrolysis of 50 % and increase with further hydrolysis. The following types of starter cultures were used for the fermentation process: Lactobacillus acidophilus; Treptococcus thermophilus, Lactobacillus bulgaricus; Streptococcus thermophiles; Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. Cremoris. The fermentation process in all samples of low-lactose milk has its own characteristics characteristic of the starter culture used. It should be noted that starter cultures, including Acidophilus bacillus, intensify the process of fermentation of the studied samples. The lactose content after the end of the fermentation process in the studied samples was 1.35; 1.4 %, which corresponds to the requirements of TR CU 027/2012 «On the safety of certain types of specialized food products, including dietary therapeutic and dietary preventive nutrition».

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28

Cargnin, Mariana Aguiar, Bruna Carla Gasparin, Derval dos Santos Rosa e Alexandre Tadeu Paulino. "Performance of lactase encapsulated in pectin-based hydrogels during lactose hydrolysis reactions". LWT 150 (ottobre 2021): 111863. http://dx.doi.org/10.1016/j.lwt.2021.111863.

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29

Gänzle, Michael G., Gottfried Haase e Paul Jelen. "Lactose: Crystallization, hydrolysis and value-added derivatives". International Dairy Journal 18, n. 7 (luglio 2008): 685–94. http://dx.doi.org/10.1016/j.idairyj.2008.03.003.

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30

Hartono, Lusiana Kresnawati, Tatik Khusniati, I. Made Artika, Sulistiani Sulistiani e Abdul Choliq. "Immobilization of Lactobacillus plantarum B134 Cells using Sodium Alginate for Lactose Hydrolysis in UHT Milk". Current Biochemistry 1, n. 2 (6 agosto 2014): 71–82. http://dx.doi.org/10.29244/cb.1.2.71-82.

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Abstract (sommario):

Hydrolysis of lactose in milk by β-galactosidase from immobilized bacterial cells has the potential to alleviate the problem of lactose intolerance. The present study was aimed to immobilize cells of L. plantarum strain B134 and evaluate their efficiency in hydrolyzing lactose in ultra high temperature (UHT) milk. Immobilized cells were generated by mixing cell suspensions with solutions of sodium alginate and calcium chloride. The β-galactosidase activity of the immobilized cells was tested by determining their ability in hydrolyzing lactose in UHT milk (whole milk and skimmed milk). Results showed that cells of L. plantarum strain B134 were entrapped optimally using a combination of 1 % sodium alginate, 100 mM calcium chloride and 12 % w/v cell suspension. The highest β-galactosidase activity was achieved at pH 6.5 and a temperature of 45 ºC for 5 minutes incubation time. The immobilization efficiency achieved was 28.95 %. The immobilized cells could reduce lactose by up to 85.45 % in UHT whole milk and 91.26 % in UHT skimmed milk. The times required for that reduction of lactose in UHT whole milk and UHT skimmed milk were 12 hours and 9 hours respectively. The immobilized cells could be re-used up to 4 times for efficient lactose hydrolysis for both types of milk. Therefore, immobilized cells of L. plantarum B134 have the potential to be used for lactose hydrolysis in UHT milk.

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31

Pimentel, Grégory, Kathryn J. Burton, Marta Rosikiewicz, Carola Freiburghaus, Ueli von Ah, Linda H. Münger, François P. Pralong et al. "Blood lactose after dairy product intake in healthy men". British Journal of Nutrition 118, n. 12 (4 dicembre 2017): 1070–77. http://dx.doi.org/10.1017/s0007114517003245.

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Abstract (sommario):

AbstractThe absence of a dedicated transport for disaccharides in the intestine implicates that the metabolic use of dietary lactose relies on its prior hydrolysis at the intestinal brush border. Consequently, lactose in blood or urine has mostly been associated with specific cases in which the gastrointestinal barrier is damaged. On the other hand, lactose appears in the blood of lactating women and has been detected in the blood and urine of healthy men, indicating that the presence of lactose in the circulation of healthy subjects is not incompatible with normal physiology. In this cross-over study we have characterised the postprandial kinetics of lactose, and its major constituent, galactose, in the serum of fourteen healthy men who consumed a unique dose of 800 g milk or yogurt. Genetic testing for lactase persistence and microbiota profiling of the subjects were also performed. Data revealed that lactose does appear in serum after dairy intake, although with delayed kinetics compared with galactose. Median serum concentrations of approximately 0·02 mmol/l lactose and approximately 0·2 mmol/l galactose were observed after the ingestion of milk and yogurt respectively. The serum concentrations of lactose were inversely correlated with the concentrations of galactose, and the variability observed between the subjects’ responses could not be explained by the presence of the lactase persistence allele. Finally, lactose levels have been associated with the abundance of theVeillonellagenus in faecal microbiota. The measurement of systemic lactose following dietary intake could provide information about lactose metabolism and nutrient transport processes under normal or pathological conditions.

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32

Santos, Pauline Thais dos, Stael Málaga Carrilho, Samanta Stinghen de Abreu, Fernanda Montanholi de Lira, Fernanda Yuri Rodrigues Tanaka, Ronaldo Tamanini, Edson Antonio Rios, Lycio Shinji Watanabe, Rafael Fagnani e Natalia Gonzaga. "Artificial intelligence applied to enzymatic hydrolysis of lactose: improving the control of industrial processes". Semina: Ciências Agrárias 43, n. 4 (10 maggio 2022): 1637–52. http://dx.doi.org/10.5433/1679-0359.2022v43n4p1637.

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Abstract (sommario):

Lactose is the main carbohydrate in milk, and its absorption occurs via enzymatic hydrolysis, generating glucose and galactose. Lactose intolerance is the reduction of intestinal hydrolysis capacity due to hypolactasia, which results in the need to consume dairy foods with low levels of this carbohydrate. β-galactosidase enzymes are used in dairy industries to hydrolyze lactose, thereby allowing intolerant consumers access to dairy products without the negative health implications. Alternative and official analytical methods are used to quantify the carbohydrate content resulting from enzymatic hydrolysis. The objective of this study was to evaluate the enzymatic hydrolysis of two distinct industrial enzymes produced by the microorganisms Bacillus licheniformis and Kluyveromyces lactis using three analytical methods: enzymatic method, cryoscopy, and high performance liquid chromatography (HPLC) using artificial intelligence to improve the control of the industrial processes. After adding the enzymes to skim milk, time kinetics was performed by collecting samples at time 0, every 10 min for 1 h, and every 30 min until the end of 5 h of hydrolysis. In 97% of the cases, a decrease in lactose concentration was observed by HPLC, followed by the deepening of the cryoscopic point. Glucose measurements by absorbance and HPLC quantification were correlated (r = 0.79; p < 0.01) but not concordant (p < 0.01). It was concluded that by means of artificial intelligence, it was possible to indirectly estimate lactose concentration using an algorithm that associates cryoscopy and glucose concentration.

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33

PATOCKA, J., e P. JELEN. "Enzymatic Lactose Hydrolysis for Prevention of Lactose Crystallization in a Whey Spread". Journal of Food Science 53, n. 5 (settembre 1988): 1370–72. http://dx.doi.org/10.1111/j.1365-2621.1988.tb09279.x.

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34

Francisquini, Júlia d'Almeida, Júlia Rocha, Evandro Martins, Rodrigo Stephani, Paulo Henrique Fonseca da Silva, Isis Rodrigues Toledo Renhe, Ítalo Tuler Perrone e Antônio Fernandes de Carvalho. "5-Hydroxymethylfurfural formation and color change in lactose-hydrolyzed Dulce de leche". Journal of Dairy Research 86, n. 4 (novembre 2019): 477–82. http://dx.doi.org/10.1017/s0022029919000815.

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AbstractThe work described in this Research Communication concerns the production of Dulce de leche (DL), that is a traditional product from South America obtained by concentration. Maillard reaction (MR) products are mainly responsible for the formation of color and flavor in this product. Lactose-hydrolyzed products have been developed to supply consumer demand, but this hydrolysis may affect the flavor, color, taste, texture and even some nutritional aspects of the product. We studied the influence of different levels of lactose-hydrolysis, sucrose addition and initial pH on the development of MR, appraised by the determination of 5-hydroxymethylfurfural (HMF). A process simulator with multi-monitoring system was used to produce 15 DL. Box-Behnken 33 experimental design was applied for the three factors: pH, lactose-hydrolysis level and sucrose concentration. Lipids, protein, ashes, carbohydrates, water activity, dissolved solids, colorimetric analysis and HMF (free and total) are among the physicochemical attributes and MR indicators analyzed in this work. The products showed significant differences in composition but all the values were in agreement with the literature. Moreover, higher levels of lactose hydrolysis and higher pH presented a direct relation with the development of MR, observed by an increase in coloration (lower luminosity) and more formation of HMF, both free and total. The present study expands the knowledge about DL spread made of lactose-hydrolyzed milk, allowing the food industries to produce a lactose free DL with nutritional and sensory characteristics closer to the traditional product.

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Lappa, Iliada K., Vasiliki Kachrimanidou, Aikaterini Papadaki, Anthi Stamatiou, Dimitrios Ladakis, Effimia Eriotou e Nikolaos Kopsahelis. "A Comprehensive Bioprocessing Approach to Foster Cheese Whey Valorization: On-Site β-Galactosidase Secretion for Lactose Hydrolysis and Sequential Bacterial Cellulose Production". Fermentation 7, n. 3 (8 settembre 2021): 184. http://dx.doi.org/10.3390/fermentation7030184.

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Abstract (sommario):

Cheese whey (CW) constitutes a dairy industry by-product, with considerable polluting impact, related mostly with lactose. Numerous bioprocessing approaches have been suggested for lactose utilization, however, full exploitation is hindered by strain specificity for lactose consumption, entailing a confined range of end-products. Thus, we developed a CW valorization process generating high added-value products (crude enzymes, nutrient supplements, biopolymers). First, the ability of Aspergillus awamori to secrete β-galactosidase was studied under several conditions during solid-state fermentation (SSF). Maximum enzyme activity (148 U/g) was obtained at 70% initial moisture content after three days. Crude enzymatic extracts were further implemented to hydrolyze CW lactose, assessing the effect of hydrolysis time, temperature and initial enzymatic activity. Complete lactose hydrolysis was obtained after 36 h, using 15 U/mL initial enzymatic activity. Subsequently, submerged fermentations were performed with the produced hydrolysates as onset feedstocks to produce bacterial cellulose (5.6–7 g/L). Our findings indicate a novel approach to valorize CW via the production of crude enzymes and lactose hydrolysis, aiming to unfold the output potential of intermediate product formation and end-product applications. Likewise, this study generated a bio-based material to be further introduced in novel food formulations, elaborating and conforming with the basic pillars of circular economy.

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Brink, Elizabeth J., Emerentia C. H. van Beresteijn, Pieter R. Dekker e Anton C. Beynen. "Urinary excretion of magnesium and calcium as an index of absorption is not affected by lactose intake in healthy adults". British Journal of Nutrition 69, n. 3 (maggio 1993): 863–70. http://dx.doi.org/10.1079/bjn19930086.

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The effect of lactose on the urinary excretion of Mg and Ca, as an index of absorption, was studied in a double-blind, crossover study during three 1-week periods. Twenty-four healthy, lactose-tolerant, adult volunteers maintained their habitual diets with the exception that all lactose-containing dairy products in the diet were replaced by 600 g/d of three specially prepared dairy products. These products were based on either lactose-enriched cow's milk or lactose-enriched, lactase (EC3.2.1.23)-treated cow's milk, with or without added Mg, and were given in turn during 1 week. Lactose intake was increased by 127 mmol/d (46 g/d) while taking the lactose-enriched products. While taking the Mg-enriched products, Mg intake was increased by 2.8 mmol/d (69 mg/d) which was equivalent to 17% of the habitual Mg intake. Apart from the lactose and Mg intake, nutrient intake was comparable during the three dietary periods. Urinary excretions of Mg and Ca were used as indicators for their absorption. Mg supplementation significantly increased urinary Mg excretion by 0.97 mmol/d (equivalent to an increase of 18%,P< 0.001), indicating that urinary Mg excretion is a valid indicator for intestinal Mg absorption. Hydrolysis of lactose did not affect urinary excretion of Mg and Ca, which implies that lactose intake does not affect the absorption of Mg and Ca in healthy adults.

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Romano, Cleunice Cassalho, Maria Josiane Sereia, Renata R. Oliveira, Thaise Pascoato Oliveira e Murilo E. S. Vieira. "Influence of inulin on chemical, sensorial and survival of L. Acidophilus in symbiotic frozen yogurt with reduced-lactose:". Revista Brasileira de Pesquisa em Alimentos 3, n. 1 (14 giugno 2013): 36. http://dx.doi.org/10.14685/rebrapa.v3i1.90.

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Recently, the dairy industry has given special attention to development of products containing low lactose content, to meet the needs of consumers intolerant to this sugar type. This study aimed to evaluate the effects of adding inulin on chemical, sensory and survival of probiotics in symbiotic frozen yogurt with reduced lactose content during the storage period. The hydrolysis degree achieved using 0.8 g of lactase per liter milk was about 97.54%, being below the limit quantification (0.5%) and being considered as a food for special purposes. Based on the results obtained, it can be concluded that the enzyme lactase effectively reduced the lactose content in frozen developed, not by changing the physicochemical and viability of probiotic culture. The addition of inulin caused a significant change (p<0.05) in sensory attributes evaluated and promoted the growth of L. acidophilus, showing that this type of edible ice cream is a good option for the dairy market, catering lactose intolerant consumers. DOI: http://dx.doi.org/10.14685/rebrapa.v3i1.90

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Neves, Leandra Natália de Oliveira, e Marcone Augusto Leal de Oliveira. "Effects of enzymatic lactose hydrolysis on thermal markers in lactose-free UHT milk". Journal of Food Science and Technology 57, n. 9 (5 giugno 2020): 3518–24. http://dx.doi.org/10.1007/s13197-020-04561-9.

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39

Luan, Shuyue, e Xuguo Duan. "A Novel Thermal-Activated β-Galactosidase from Bacillus aryabhattai GEL-09 for Lactose Hydrolysis in Milk". Foods 11, n. 3 (27 gennaio 2022): 372. http://dx.doi.org/10.3390/foods11030372.

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Abstract (sommario):

β-Galactosidase has been greatly used in the dairy industry. This study investigated a novel thermostable β-galactosidase (lacZBa) from Bacillus aryabhattai GEL-09 and evaluated the hydrolytic performance of this enzyme. Firstly, the lacZBa-encoding gene was cloned and overexpressed in Escherichia coli BL21(DE3). Phylogenetic analyses revealed that lacZBa belonged to the glycoside hydrolase family 42. Using SDS-PAGE, we determined that the molecular weight of lacZBa was ~75 kDa. Purified lacZBa exhibited a maximum activity at 45 °C, pH 6.0, and could be activated following incubation at 45 °C for several minutes. The half-life of lacZBa at 45 °C and 50 °C was 264 h and 36 h, respectively. While Co2+, Mn2+, Zn2+, Fe2+, Mg2+, and Ca2+ enhanced enzymatic activity, Cu2+ and ethylenediaminetetraacetic acid inhibited enzymatic activity. Moreover, lacZBa could hydrolyze lactose and oNPG with Km values of 85.09 and 14.38 mM. Molecular docking results revealed that lacZBa efficiently recognized and catalyzed lactose. Additionally, the hydrolysis of lactose by lacZBa was studied in lactose solution and commercial milk. Lactose was completely hydrolyzed within 4 h with 8 U/mL of lacZBa at 45 °C. These results suggested that lacZBa identified in this study has potential applications in the dairy industry.

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40

Alves, Érika de Pádua, Alessandra Bosso, Luiz Rodrigo Ito Morioka e Hélio Hiroshi Suguimoto. "Cell permeabilization of Kluyveromyces and Saccharomyces species to obtain potential biocatalysts for lactose hydrolysis". Acta Scientiarum. Biological Sciences 44 (18 maggio 2022): e60336. http://dx.doi.org/10.4025/actascibiolsci.v44i1.60336.

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Abstract (sommario):

Yeast’s beta-galactosidase is an intracellular enzyme, through which it is possible to determine in vivo its activity as a biocatalyst in the lactose hydrolysis. Permeabilization process was used for transforming the microorganisms cells into biocatalysts with an enhanced enzyme activity. The potential application of this enzyme technology in industrial process depends mainly on the enzyme activity. Beta-galactosidase enzyme that hydrolyzes lactose, for instance, is largely dependent on the reaction time and its stability under different physical conditions, such as pH, temperature and enzyme concentration. The objective of this study was to optimize the cellular permeabilization process of Kluyveromyces marxianus CCT 3172 and Saccharomyces fragilis CCT 7586 cultured in cheese whey for lactose hydrolysis. Box-Behnken design was carried out for cell permeabilization with three independent variables, ethanol concentration, permeabilization time and temperature. The best permeability conditions for K. marxianus CCT 3172 were 27% (v v-1) ethanol, 3 min at 20ºC, with specific enzymatic activity of 0.98 U mg-1. For S. fragilis CCT 7586, a specific enzymatic activity of 1.31 U mg-1 was achieved using 45% (v v-1) of ethanol, 17 min. of reaction under 17ºC. Thus, it was concluded that cellular permeabilization with ethanol is an efficient process to determine beta-galactosidase activity.

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41

Mörschbächer, Ana Paula, Giandra Volpato e Claucia Fernanda Volken de Souza. "Kluyveromyces lactis β-galactosidase immobilization in calcium alginate spheres and gelatin for hydrolysis of cheese whey lactose". Ciência Rural 46, n. 5 (maggio 2016): 921–26. http://dx.doi.org/10.1590/0103-8478cr20150833.

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Abstract (sommario):

ABSTRACT: One of the greatest challenges for dairy industries is the correct destination of all the whey generated during cheese making, considering its high impact, the large volume created, and its technological potential. Enzymatic hydrolysis of cheese whey lactose is a biotechnological alternative. However, one of the limiting factors of its use is the relatively high cost of the enzymes, which could be lowered with the immobilization of these biocatalysts. Considering this context, the objective of this research was to evaluate the commercial Kluyveromyces lactis β-galactosidase enzyme immobilized in calcium alginate spheres and gelatin, using glutaraldehyde and concanavalin A (ConA) as modifying agents in the hydrolysis of cheese whey lactose process. Results have shown that the enzyme encapsulation complexed with ConA in alginate-gelatin spheres, without glutaraldehyde in the immobilization support, has significantly increased the hydrolysis of lactose rate, achieving a maximum conversion of 72%.

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42

Li, Dandan, Shangyong Li, Yanhong Wu, Mengfei Jin, Yu Zhou, Yanan Wang, Xuehong Chen e Yantao Han. "Cloning and Characterization of a New β-Galactosidase from Alteromonas sp. QD01 and Its Potential in Synthesis of Galacto-Oligosaccharides". Marine Drugs 18, n. 6 (14 giugno 2020): 312. http://dx.doi.org/10.3390/md18060312.

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As prebiotics, galacto-oligosaccharides (GOSs) can improve the intestinal flora and have important applications in medicine. β-galactosidases could promote the synthesis of GOSs in lactose and catalyze the hydrolysis of lactose. In this study, a new β-galactosidase gene (gal2A), which belongs to the glycoside hydrolase family 2, was cloned from marine bacterium Alteromonas sp. QD01 and expressed in Escherichia coli. The molecular weight of Gal2A was 117.07 kDa. The optimal pH and temperature of Gal2A were 8.0 and 40 °C, respectively. At the same time, Gal2A showed wide pH stability in the pH range of 6.0–9.5, which is suitable for lactose hydrolysis in milk. Most metal ions promoted the activity of Gal2A, especially Mn2+ and Mg2+. Importantly, Gal2A exhibited high transglycosylation activity, which can catalyze the formation of GOS from milk and lactose. These characteristics indicated that Gal2A may be ideal for producing GOSs and lactose-reducing dairy products.

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43

Genari, A. N., F. V. Passos e F. M. L. Passos. "Configuration of a Bioreactor for Milk Lactose Hydrolysis". Journal of Dairy Science 86, n. 9 (settembre 2003): 2783–89. http://dx.doi.org/10.3168/jds.s0022-0302(03)73875-2.

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44

Mariotti, Marcela Panaro, Hideko Yamanaka, Angela Regina Araujo e Henrique Celso Trevisan. "Hydrolysis of whey lactose by immobilized β-Galactosidase". Brazilian Archives of Biology and Technology 51, n. 6 (dicembre 2008): 1233–40. http://dx.doi.org/10.1590/s1516-89132008000600019.

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Hydrolysis of whey lactose to glucose and galactose by immobilized galactosidase comes as an alternative to enlarge the possibilities of commercial use of this feedstock. To be applied at industrial scale, the process should be performed continuously .This work aimed to study the hydrolysis of whey lactose by an immobilized enzyme reactor. b-Galactosidase from Aspergillus oryzae was immobilized on silica and activity and stability were evaluated. The best immobilization results were attained by using glutaraldehyde as support's activator and enzyme stabilizer. The optimized enzyme proportion for immobilization was 15-20 mg g-1 of support. Treatments of whey were performed (microfiltration, thermal treatment and ultrafiltration), seeking the elimination of sludge, and the effects on operating the fixed bed reactor were evaluated. Ultrafiltration was the best treatment towards a proper substrate solution for feeding the reactor.

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45

JACKSON, ERIC H., e PAVEL JELEN. "Batch Hydrolysis of Lactose in Concentrated Whey Systems". Journal of Food Science 54, n. 4 (luglio 1989): 1086–87. http://dx.doi.org/10.1111/j.1365-2621.1989.tb07953.x.

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46

Vento, Máximo, e Manuel Moya. "Lactose hydrolysis and calcium absorption in premature feeding". Journal of Pediatrics 142, n. 6 (giugno 2003): 737–38. http://dx.doi.org/10.1067/mpd.2003.252.

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47

Mahoney, Raymond R. "Galactosyl-oligosaccharide formation during lactose hydrolysis: A review". Food Chemistry 63, n. 2 (ottobre 1998): 147–54. http://dx.doi.org/10.1016/s0308-8146(98)00020-x.

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48

Batsalova, Katerina, Kostadin Kunchev, Yana Popova, Annie Kozhukharova e Nadezhda Kirova. "Hydrolysis of lactose by ?-galactosidase immobilized in polyvinylalcohol". Applied Microbiology and Biotechnology 26, n. 3 (giugno 1987): 227–30. http://dx.doi.org/10.1007/bf00286313.

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49

HUH, K., T. TOBA e S. ADACHI. "Oligosaccharide structures formed during acid hydrolysis of lactose". Food Chemistry 39, n. 1 (1991): 39–49. http://dx.doi.org/10.1016/0308-8146(91)90083-z.

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50

Chen, Kuo-Cheng, Jer-Yiing Houng e Alvin C. Ling. "Product inhibition of the enzymatic hydrolysis of lactose". Enzyme and Microbial Technology 7, n. 10 (ottobre 1985): 510–14. http://dx.doi.org/10.1016/0141-0229(85)90153-x.

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