Rennet, Bovine

IDF (1992) Bovine Rennets. Determination of Total Milk-clotting Activity, Provisional Standard 157, International Dairy Federation, Brussels. 

Linklater (1961) reported that bovine pepsin accounted for only 0 to 6% of the milk-clotting activity of commercial rennet extracts. He used porcine pepsin as a reference standard. Bovine pepsin has increased in use as a coagulant because of the practice of extracting the stomach from older calves and adult cattle. More recently, Sellers (1982) reported that 85 to 95% of the proteolytic activity of calf rennet is due to chymosin and the remainder is from bovine pepsin. Adult bovine rennets preparations may contain 55 to 60% bovine pepsin. Mixtures of calf rennet and porcine pepsin may contain 40 to 45% chymosin, 5 to 10% bovine pepsin, and 50% porcine pepsin. Mixtures of adult bovine rennet and porcine pepsin typically contain 20 to 25% chymosin, 40 to 45% bovine pepsin, and 30 to 40% porcine pepsin activity (McMahon and Brown 1985). 

Three illustrations are used to review the various approaches taken by the enzyme industry in tailoring enzyme preparations to meet the production and product quality needs of the food industry. Tailored enzyme preparations have been able to convert the corn syrup industry from an acid-based industry to an enzyme-based industry, to overcome the problems created in the baking industry as grain technology improved and automation was introduced, and to rescue the cheese industry as the supply of bovine rennet decreased and the demand for cheese and cheese flavor increased. 

Standard Preparation Use a standard-strength rennet, bovine rennet, microbial rennet (Endothia parasitica), or microbial rennet (Mucor species), as appropriate for the preparation to be assayed. Such standards, which are available from commercial coagulant manufacturers, should be of known activity. Dilute the standard-strength material 1 to 200 with water, and mix. Equilibrate to 300 before use, and prepare no more than 2 h before use. 

Beta-1,3-glucan, 15 Bleidner Apparatus, 17 Borneol, 66, 96 Bovine Rennet, 18 Brilliant Blue FCF, 24 Bromelain, 18... 

Borneol, (S3)66, 96 Bornyl Acetate, 460, 648 Z-Bornyl Acetate, 460 Bound Styrene, 782 Bovine Rennet, 133, (S3) 18 Brewer s Yeast, 440 Brilliant Blue FCF, 139, (S3)24 Bromelain, 132, 786, (S3)18 Bromide Identification Test, 753 Brominated Vegetable Oil, 48 Bromine, 0.1 N, 856 Bromine TS, 850 Bromine Water, 850 Bromocresol Blue, 860 Bromocresol Blue TS, 850... 

Martin, P., Collin, J.-C., Garnot, P., Ribadeau Dumas, B., and Mocquot, G. (1981). Evaluation of bovine rennets in terms of absolute concentrations of chyraosin and pepsin A. J. Dairy Res. 48, 447-456. 

Bovine rennet. See Rennet Bovlon. See Polyvinyl alcohol Bowax 2015. See Polyethylene wax Bowax . See Microcrystalline wax Bozepole CV. See Acrylamide/ammonium acrylate copolymer... 

CAS 9001-98-3 9042-08-4 Synonyms Bovine rennet Chymosin Rennase Rennet, calf Rennin Rennin, calf... 

About 20% of the total protein of bovine milk belongs to a group of proteins generally referred to as whey or serum proteins or non-casein nitrogen. Acid and rennet wheys also contain casein-derived peptides both contain proteose-peptones, produced by plasmin, mainly from /J-casein, and the latter also contains (glyco)macropeptides produced by rennets from K-casein. These peptides are excluded from the present discussion. 

Green (1972) reported that Cheddar cheese made entirely with bovine pepsin was only slightly inferior to that made with calf rennet and Fox and Walley (1971) found no significant difference between Cheddar cheese made with bovine pepsin and rennet. Fox (1969) found that the milk-clotting activity of bovine pepsin is less pH-dependent than that... 

Fox, P. F. 1969. Milk-clotting and proteolytic activities of rennet, and of bovine pepsin and porcine pepsin. J. Dairy Res. 36, 427-433. 

Green, M. L. 1972. Assessment of swine, bovine and chicken pepsins as rennet substitutes for Cheddar cheesemaking. J. Dairy Res. 39, 261-273. 

Proteolysis of casein begins with the addition of rennet to the milk and the formation of a coagulum. Calf rennet is actually 80% chymosin and 20% bovine pepsin A (Grappin et al 1985). Rennet can remain active in Cheddar and Camembert cheeses for up to three months, but... 

The primary (enzymatic) phase of renneting overlaps somewhat with the secondary phase of aggregation. The gel subsequently undergoes syneresis to produce curds and whey while a slow but more general proteolysis of the caseins begins, which eventually contributes substantially to the distinctive flavor and texture of cheese. The enzymatic coagulation of milk and formation of the curd has been reviewed by Dalgleish (1987). Here, attention will be confined to parts of the subject that most clearly relate to the structure and stability of bovine casein micelles. 

Rennet, Bovine Aqueous extracts made from the fourth stomach of bo vines. Produced as a clear, amber to dark brown liquid or a white to tan powder. Major active principle protease (pepsin). Typical application used in the manufacture of... 

Rennet (bovine and calf) Hydrolysis of polypeptides specificity may be similar to pepsin. 

Phospholipase A2, 18 Rennet, Bovine, 18 Rennet, Calf, 18 Trypsin, 18... 

Zobrist, M.R., Huppertz, T., Uniacke, T., Fox, PR, and Kelly, A.L. 2005. High pressure induced changes in the rennet coagulation properties of bovine milk. International Dairy Journal 15 655-662. 

The amino acid composition of some )S-lg variants is shown in Table 4.4. It is rich in sulphur amino acids which give it a high biological value of 110. It contains 2 moles of cystine and 1 mole of cysteine per monomer of 18 kDa. The cysteine is especially important since it reacts, following heat denatura-tion, with the disulphide of K-casein and significantly affects rennet coagulation and the heat stability properties of milk it is also responsible for the cooked flavour of heated milk. Some /S-lgs, e.g. porcine, do not contain a free sulphydryl group. The isoionic point of bovine j3-lgs is c. pH 5.2. 

The properties and biological function of LPO have recently been reviewed. This secretory peroxidase is isolated from cow s milk. Crystalline LPO from bovine milk was obtained in 1943 and shown to be green colored like MPO. Its isolation and purification was simplified by precipitation of casein by rennet. The enzyme with a single polypeptide chain has been known to exist as several isoenzyme forms. The Soret maxima of LPO of 412 nm with molar absorptivity of 112 mM cm is typical of most peroxidases. It recently has been demonstrated that the heme in LPO is attached to the protein by ester bonds between the heme 1- and 5-methyl groups, and Glu375 and Asp275, respectively. ... 

Chicken pepsin is the least suitable of these and is used widely only in Israel. Bovine pepsin is probably the most satisfactory and many commercial calf rennets contain up to 50% bovine pepsin its proteolytic specificity is generally similar to that of calf chymosin. The proteolytic specificities of the three principal fungal rennets are considerably different from that of calf chymosin but the acceptability of most cheese varieties made using fungal rennets is fairly good. Microbial rennets are widely used in the United States but to only a limited extent in Europe. The extensive literature on rennet substitutes has been reviewed by Sardinas (1972), Emstrom and Wong (1974), Nelson (1975), Green (1977), and Phelan (1985). 

The coagulation of renneted micelles is very temperature-dependent (Gio 16) and normal bovine milk does not coagulate <18°C unless [Ca ] is increased. The marked difference between the temperature dependence of the enzymatic and nonenzymatic phases of rennet coagulation has been exploited in the study of the effect of various factors on rennet coagulation, in attempts to develop a system for the continuous production of cheese or casein curd and in the application of immobilized rennets. The very high dependence on temperature of rennet coagulation suggests that hydrophobic interactions play a major role. 

Calf rennet contains about 10% bovine pepsin (EC 3.4.23.1, Rothe et ai, 1977). The proteolytic products produced from Na-caseinate by bovine pepsin are similar to those produced by chymosin (Fox, 1%9), although as far as we are aware the specificity of bovine or porcine pepsins on bovine caseins has not been rigorously determined. 

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