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Química Nova

Print version ISSN 0100-4042On-line version ISSN 1678-7064

Abstract

PIRES, Miryam S.; ALESSI, Adriana  and  GATTI, Carlos A.. Laboratory study of the effect of the calcium and casein concentration, pH and temperature on the incorporation of dairy proteins to the coagulum obtained by enzimatic action. Quím. Nova [online]. 1999, vol.22, n.4, pp.497-500. ISSN 0100-4042.  http://dx.doi.org/10.1590/S0100-40421999000400005.

The effect of casein concentration, Ca2+ concentration, temperature and pH on the amount and size of protein aggregates (fines) in the whey produced by enzimic coagulation of nonfat milk was studied in laboratory conditions. Casein concentrations about 0.3 g/L showed a minimal amount of caseins in the whey, with presence of small aggregates of casein micellles. Ca2+ concentrations higher than 5 mM were neccesary to reduce the whey protein to a minimum constituted by protein particles smaller than casein micelles. The coagulation temperature, in the 35 - 45oC range, produced almost no variations in the whey proteins. The obtention of a minimum amount of whey proteins was possible only in a narrow pH range around 6.4. These results pointed to casein concentration and pH as important variables to be controlled in connection with the process yield.

Keywords : casein micelles; enzymic coagulation.

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