Enzyme hydrolyzed casein

The following description is from U.S. Patent 2,701,227 To 50 liters of distilled water there was added 10.17 kg of enzyme hydrolyzed casein (N-Z-Amine). The temperature was raised to 100°C and held until the casein digest solution was clear. The container was then cooled rapidly to 15°C and the cooled solution filtered through a coarse grade of filter paper. A small amount of toluene was added as a preservative and the solution... 

Cheese is ripened for 6 months to 1 year or longer at 5° to 15°C and 70-75% relative humidity. Cheese ripening is a complex process involving a combination of chemical, biochemical, and physical reactions. Proteolytic enzymes, e.g., rennet and lactic starter culture enzymes, hydrolyze caseins to produce flavor compounds and proper body. Lipase and lactase enzymes also hydrolyze their respective substrates to produce a large number of characteristic flavor compounds (Reiter and Sharpe 1971 Harper 1959 Law 1981 Schmidt etal. 1976), including free fatty acids, methanethiol, methanol, dimethyl sulfide, diacetyl, acetone, and others (Moskowitz 1980). 

Streptomyces sp. NRRL 1143 Bacto yeast extract Enzyme hydrolyzed casein... 

Enzymes can be coupled to the surface of a very open-pored silica gel to obtain a relatively stable fixed enzymatic catalyst (282). Porous silica with a pore diameter of 51 nm was used as a carrier to the surface of which the enzyme B. subtilic protease was attached, a bifunctional diazonium salt-was reacted with the surface of the silica, followed by reaction of enzyme with the other end of the diazonium molecule. The silica-supported enzyme hydrolyzed casein and had a half-life of more than 7 months whereas that of enzyme simply adsorbed on the silica was 2.5 months. 

Minervini, F., Algaron, F., Rizzello, C. G., Fox, P. F., Monnet, V., and Gobbetti, M. 2003. Angiotensin I-converting-enzyme-inhibitory and antibacterial peptides from Lactobacillus helveticus PR4 proteinase-hydrolyzed caseins of milk from six species. Appl. Env. Microbiol., 69,5297-5305. 

A proteolytic enzyme secreted by gastrie mueosa of infants is chymosin (rennin), which functions to clot milk and promote its digestion by preventing rapid passage from the stomach. Chymosin hydrolyzes casein, a mixture of several related milk proteins, to paracasein, whieh reacts with Ca + to yield the insoluble curd. Pepsin performs the same funetions as chymosin. Chymosin is found in the fourth stomach of ruminants. Calf stomach is a source of this enzyme, which is used in the manufacture of cheese. Chymosin has been synthesized by recombinant DNA techniques and successfully used in the produetion of cheese. 

Since the copolyamide contained two different amide bonds, both of which were similar, but not identical to a peptide bond, it was hoped that the extracellular enzymes of the bacteria or fungi would cleave the polymer to small fragments that could be utilized by the microoganisms as a food. In a fast screening technique, a culture of bacteria and/or fungi was fed a standard amount of hydrolyzed casein and the amount and rate of carbon dioxide liberated was monitored. In order to determine whether a material was biodegradable on the time scale used, the material was added to a similar flask and any increase in the rate or amount of carbon dioxide over the control was noted (5,6h... 

Enzyme stability at 40°C is demonstrated in Figure 3.101 for the complex. A reactor was operated continuously for two weeks at 20°C hydrolyzing casein with no loss in enzyme activity. 

Functional properties of some enzymatically modified and EPM-treated products of milk proteins [136] were determined as follows. An enzymatically prehydrolyzed commercial milk protein concentrate (SR) without further hydrolysis, and casein hydrolyzed by alcalase, a-chymotrypsin, and papain, respectively, were used as substrates in the EPM reaction. The concentration of the hydrolysates was 20% w/ v in the EPM reactions. A methionine methyl ester hydrochloride/ substrate ratio of 1 5 was used for incorporating this amino acid. After incubation, the products with methionine incorporation were simultaneously dialyzed for 2 days through a cellophane membrane against distilled water. The nondialyzable fractions and the EPM products without amino acid enrichment were freeze-dried. Covalent methionine incorporation in the EPM products with amino acid enrichment was verified by exopeptidase hydrolysis of the protein chains. The functional properties of the different EPM products are summarized in Table 1. An important functional property of proteins and/or peptide mixtures is their emulsifying behavior. This is highly influenced by the molecular structure, the position and ratio of hydrophobic-hydrophilic amino acids. Emulsion activity was found to be low (34.0) for casein, and the values determined for enzyme hydrolyzed and modified products were in general even lower. The papain hydrolysate, sample H3, showed here a different behavior as well this was the one of the sample series that had the highest EAI value (43.0). The emulsion stability of the enzymatically modified products displayed tendencies quite opposite to the values of emul-... 

Hydrolyzed beeswax Synonyms Beeswax, hydrolyzed Definition Hydrolysate of beeswax derived by acid, enzyme or other method of hydrolysis Uses Surfactant, emulsifier, emulsion stabilizer in cosmetics Hydrolyzed casein... 

In this discussion we will be principally concerned with the crystal structure analysis of the acid proteinase from Endothia parasitica, an enzyme that is easily purified and crystallized (1,2). It rapidly clots milk at pH 5-6.5 and hydrolyzes casein and hemoglobin at maximum rates at pH 2-2.5 (3). Hydrolysis of the oxidized B-chain of insulin shows that this proteinase has a specificity for... 

Casein hydrolyzates are produced from dried casein. With appropriate heat treatment and the addition of alkaHes and enzymes, digestion proceeds. FoUowing pasteurization, evaporation (qv), and spray drying, a dried product of 2—4% is obtained. Many so-called nondairy products such as coffee cream, topping, and icings utilize caseinates (see Dairy SUBSTITUTES). In addition to fulfilling a nutritional role, the caseinates impart creaminess, firmness, smoothness, and consistency of products. Imitation meats and soups use caseinates as an extender and to improve moistness and smoothness. 

This enzyme [EC 3.4.21.53], also known as endopepti-dase La, ATP-dependent serine proteinase, and ATP-dependent protease La, catalyzes the hydrolysis of peptide bonds in large proteins (for example, globin, casein, and denaturated serum albumin) in the presence of ATP (which is hydrolyzed to ADP and orthophosphate). Vanadate ion inhibits both reactions. A similar enzyme occurs in animal mitochondria. Protease La belongs to the peptidase family S16. 

The other major casein in cheese is /3-casein, but it is generally not hydrolyzed by rennet in low-pH cheeses. Alkaline milk protease (plas-min) plays the major role in the hydrolysis of /3-casein (Richardson and Pearce 1981). The plasmin level in cheese is related to the pH of the curd at whey drainage, since plasmin dissociates from casein micelles as the pH is decreased. Richardson and Pearce (1981) found two or three times more plasmin activity in Swiss cheese than in Cheddar cheese. Swiss cheese curds are drained at pH 6.4 or higher, while Cheddar cheese curds are drained at pH 6.3 or lower. Proteolysis of /3-casein is significantly inhibited by 5% sodium chloride. The inhibitory influence of sodium chloride is most likely due to alteration of /3-casein or a reduction in the attractive forces between enzyme and substrate (Fox and Walley 1971). 

Casein is not coagulated by heat. It is precipitated by acids and by rennin. a proteolytic enzyme obtained from the stomach or calves. Casein is a conjugated protein belonging lo the group uf phosphoproteins. The enzyme trypsin can hydrolyze off a phosphorus-containing peptone. 

Siitas, Y., Soppi, E., Korhonen, H., Syvaoja, E.L., Saxelin, M., Rokka, T., and Isolauri, E. 1996. Suppression of lymphocyte proliferation in vitro by bovine caseins hydrolyzed with Lactobacillus casei GG-derived enzymes. J Allergy Clin Immunol 98 216-224. 

One of the applications of enzymes in the preparation of food gels is the production of cheese. During this process, chymosin hydrolyzes a specific bond of K-casein, resulting in the destabilization of the micelle structure followed by aggregation and formation of an insoluble coagulum. 

Synthetic substrates allow rapid determination of the catalytic constants of an enzyme. Nevertheless, it is known that the environment of the peptide bond depends largely on physico-chemical conditions of the applied media, and imposed steric hindrance. Since these parameters are important, the hydrolysis of purified (3-casein was studied at different pHs. The kinetic analysis revealed that the mutant conserved the native trypsin capacity to hydrolyze peptide bonds containing arginyl and lysyl residues. The optimal pH of activity changed considerably according to the mutation. 

Modifications introduced by the mutations were central to the alteration of the specificities of the enzymes studied, which were capable of cleaving (3-casein at many new sites, for example, hydrolyzing the fragment Argl-Lysl05, reported to be a trypsin inhibitor (Bouhallab et al, 1997). Since many tryptic inhibitors contain amidated Glu and Asp, and form amyloid structures, the mutants of this type could be used for the hydrolysis of the lytically resistant protein structures. 

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