Hydrolysis casein

B.C.—cheese making by casein hydrolysis with calf stomach extract (calf... 

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. 

Enzyme activities are based on rates of casein hydrolysis under defined conditions. The products of casein hydrolysis, as defined in this protocol, are those peptides soluble in 5% TCA that can be detected by the bicinchoninic acid (BCA) protein assay (unitbi.i). The amount of TCA-soluble peptide generated during the course of the reaction can actually be quantified by any one of several protein/peptide assays. The color yield in these assays is assumed to be proportional to the amount of peptide in solution. The amount of product/peptide in the reaction mixture is often reported as bovine serum albumin (BSA) equivalents—since standard curves based on this protein may be used to calibrate the assay. Thus, activity units can be expressed as the amount of BSA equivalents generated per unit time. 

The specific activities of penicillolysin for clupeine and casein hydrolysates were 3.04 x 10 1 and 5.23 x 10 3 katal/kg protein at pH 7.0, respectively (Table 9) [69], The rate of clupeine hydrolysis was 60-fold greater than that for casein hydrolysis. When zinc is removed, the enzyme is completely inactive, and readdition of zinc restores the dual activities towards clupeine and casein (Table 9). Depending on the casein substrate, the cobalt-penicillolysin (Co-penicillolysin) could be up to ca 1.6 times more active than the native zinc enzyme. On the other hand, in clupeine-hydrolysis, the cobalt enzyme is about 70% as active as the native enzyme. Thus, replacement of the zinc-penicillolysin with cobalt markedly decreases the activity towards clupeins while increases it towards casein. 

The rate of clupeine hydrolysis is 60-fold greater than that for casein hydrolysis at pH 7.0. High affinity towards the Pro-j-X, Arg-j-Arg, and hydrophobic residue (Pi)-f-X. 

Creamer, L.K. 1971. Beta-casein hydrolysis in Cheddar cheese ripening. N.Z. J. Dairy Sci. Technol. 6, 91. 

Cheese making (coagulation) by casein hydrolysis using pure microbial rennet Chymosin... 

Sharma, S.K., Mittal, G.S., and Hill, A.R. (1994). Effect of milk concentration, pH and temperature on K-casein hydrolysis at aggregation, coagulation and curd cutting times of ultrafiltered milk. Milchwissenschaft 49,450-453. 

Casamino acids, commercial acid-hydrolyzed casein. Hydrolysis is carried out until all the nitrogen in the casein is converted to amino acids or other compounds of relative chemical simplicity. Prepn Mueller, Miller, J. Immunol 40, 21 (1941) Mueller, Johnson, ibid. 33. Typical analysis N 10%, NaCI 14%, ash 20%, phosphorus as P04 2%, Fe 15 mg/3 g. 

Reid, J. R., Ng, K. H., Moore, C. H., Coolbear, T., and Pritchard, G. G. (1991b). Comparison of bovine /3-casein hydrolysis by Pj and Pm-type proteinase from Lactobacillus [sic] lactis subsp. cremoris. Appl. Microbiol. Biotechnol. 36, 344-351. 

Stability and stabilization of enzymes. Elsevier, Amsterdam, pp 111-131 Munro PA, Dunnill P, LiUy MD (1981) Casein hydrolysis in a stirred tank reactor using chy-motrypsin immobilized on magnetic supports. Biotechnol Bioeng 17(10) 1515-1528 Naik S, Karanth N (1978) Effect of internal and external diffusion on the apparent stabiUty of immobUised enzyme catalysts. J Appl Chem Biotechnol 28 569-580 O Fagain C (2003) Enzyme stabilization - recent experimental progress. Enzyme Microb Technol 33 137 149... 

Stressler, T., Eisele, T., Fischer, L. (2013). Simultaneous monitoring of twelve angiotensin I converting enzyme inhibitory peptides during enzymatic 3-casein hydrolysis using Lactobacillus peptidases. International Dairy Journal, 30, 96-102. 

Milk Caseins Hydrolysis with pepsin YFYPEL Suetsuna et al. (2000)... 

Casein hydrolysis Hydrochloric acid 20,600 Braverman and Berk, 1976... 

The main role of propionic acid bacteria in cheese ripening consists in the utilization of lactate produced by lactic acid bacteria as an end product of lactose fermentation. Lactate is then transformed into propionic and acetic acids and CO2. The volatile acids provide a specific sharp taste and help preserve a milk protein, casein. Hydrolysis of lipids with the formation of fatty acids is essential for the taste qualities of cheese. The release of proline and other amino acids and such volatile compounds as acetoin, diacetyl, dimethylsulfide, acetaldehyde is important for the formation of cheese aroma. Carbon dioxide released in the processes of propionic acid fermentation and decarboxylation of amino acids (mainly) forms eyes, or holes. Propionic acid bacteria also produce vitamins, first of all, vitamin At the same time, an important condition is to keep propionibacteria from growing and producing CO2 at low temperatures, since this would cause cracks and fissures in cheese. 

The casein hydrolysis was determined essentially according to Berg-meyer, with minor modifications to overcome problems encountered with the insoluble conjugates. The absorbance of the solution or the supernatant at 280 nm was plotted against the enzyme weight to evaluate the enzymatic activity. The hydrolytic activity of papain was determined in a similar manner, except that the assay medium contained 2mH EDTA and SmH cystein. 

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