Dairy hydrolysis

Dairy Hydrolysis of milk fat Cheese ripening Modification butter fat Elavour compounds Cheese, cheese flavour Butter, butter flavour... 

Two other practical appHcations of en2yme technology used in dairy industry are the modification of proteins with proteases to reduce possible allergens in cow milk products fed to infants, and the hydrolysis of milk with Hpases for the development of Hpolytic flavors in speciaHty cheeses. 

Another established application in the dairy industry is the hydrolysis of lactose in milk and whey by lactases. Diminished digestibility problems, increased sweetness and prevention of lactose-crystal formation are the results. The lactose hydrolysis is worked out as a case later in this chapter (section 3.6). 

By pre-treating milk with lactase, all adults can enjoy milk and a whole range of other lactose-free dairy products can be made such as ice cream and yogurt. In the production of ice cream, lactose hydrolysis can also be used to improve certain properties such as the texture, sweetness and tendency to crystallize. The increased sweetness is also advantageous in the manufacture of flavored milk products because less sugar needs to be added. 

Butyric acid is a carboxylic acid also classified as a fatty acid. It exists in two isomeric forms as shown previously, but this entry focuses on n-butyric acid or butanoic acid. It is a colorless, viscous, rancid-smelling liquid that is present as esters in animal fats and plant oils. Butyric acid exists as a glyceride in butter, with a concentration of about 4% dairy and egg products are a primary source of butyric acid. When butter or other food products go rancid, free butyric acid is liberated by hydrolysis, producing the rancid smell. It also occurs in animal fat and plant oils. Butyric acid gets its name from the Latin butyrum, or butter. It was discovered by Adolf Lieben (1836—1914) and Antonio Rossi in 1869. 

Smart, J.B. (1993) Transferase reactions of /3-galactosidases - New product opportunities, in Lactose Hydrolysis, Bulletin 239, International Dairy Federation, Brussels, pp. 16-22. 

Milk contains about 0.1 mg niacin per 100 g and thus is not a rich source of the preformed vitamin. Tryptophan contributes roughly 0.7 mg NE per 100 g milk. In milk, niacin exists primarily as nicotinamide and its concentration does not appear to be affected greatly by breed of cow, feed, season or stage of lactation. Pasteurized goats (0.3 mg niacin and 0.7 mg NE from tryptophan per 100 g) and raw sheep s (0.4 mg niacin and 1.3 mg NE from tryptophan per 100 g) milk are somewhat richer than cows milk. Niacin levels in human milk are 0.2 mg niacin and 0.5 mg NE from tryptophan per 100 g. The concentration of niacin in most dairy products is low (Appendix 6A) but is compensated somewhat by tryptophan released on hydrolysis of the proteins. 

Kannan, A. and Basu, K. P. 1951. Energy of activation of hydrolysis of sodium phenyl phosphate by milk phosphatase and on the inactivation of the enzyme by heat. Indian J. Dairy Sci. 4, 8-15. 

Luhtala, A., Korhonen, H., Koskinen, E. H. and Antila, M. 1970A. Glyceride synthesis and hydrolysis caused by cells in milk. 18th Int. Dairy Congr. Proc. IE., 80. 

Willart, S. and Sjostrom, G. 1959. The effect of sodium chloride on the hydrolysis of the fat in milk and cheese. 15th Int. Dairy Congr. Proc. 3, 1482-1486. 

Coughlin, J. R. and Nickerson, T. A. 1975. Acid-catalyzed hydrolysis of lactose in whey and aqueous solutions. J. Dairy Sci. 58, 169-174. 

Mulherin, B., Muller, T., Delaney, R. A. M. and Harper, W. J. 1979. Acid catalyzed hydrolysis of lactose with cation exchange resins. N.Z. J. Dairy Sci. Technol. 14, 127. 

Roberts, H. R. and McFarren, E. F. 1953. The chromatographic observation of oligosaccharides formed during lactose hydrolysis of lactose. J. Dairy Sci. 36, 620-632. 

Stadhouders, J. and Veringa, H. A. 1973. Fat hydrolysis by lactic acid bacteria in cheese. Neth. Milk Dairy J. 27, 77-91. 

Toba, T. and Adachi, S. 1978. Hydrolysis of lactose by microbial /3-galactosidases. Formation of oligosaccharides with special reference to 2-o-/3-i>galactopyranosyl-D-glu-cose. J. Dairy Sci. 61, 33-38. 

Trieu-Cuot, P. and Gripon, J. C. 1981. Casein hydrolysis by Penicillium caseicolum and Penicillium roqueforti proteinases A study with isoelectric focusing and two-dimensional electrophoresis. Neth Milk Dairy J. 35, 353-357. 

Zevaco, C. and Desmazeaud, J. 1980. Hydrolysis of (3-casein and peptides by intracellular neutral protease of Streptococcus diacetylactis. J. Dairy Sci. 63, 15-24. 

Enzymatic hydrolysis is a nondestructive alternative to saponification for removing triglycerides in vitamin K determinations. For the simultaneous determination of vitamins A, D, E, and K in milk- and soy-based infant formulas and dairy products fortified with these vitamins (81), an amount of sample containing approximately 3.5-4.0 g of fat was digested for 1 h with lipase at 37°C and at pH 7.7. This treatment effectively hydrolyzed the glycerides, but only partially converted retinyl palmitate and a-tocopheryl acetate to their alcohol forms vitamin D and phyllo-quinone were unaffected. The hydrolysate was made alkaline in order to precipitate the fatty acids as soaps and then diluted with ethanol and extracted with pentane. A final water wash yielded an organic phase containing primarily the fat-soluble vitamins and cholesterol. 

H Montijano, FA Tomas-Barberan, F Borrego. Accelerated kinetics study of neohesperidin DC hydrolysis under conditions relevant to high temperature processed dairy products. Z Lebensm Unters Forsch 204(3) 180-182, 1997. 

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