Physical-mathematical model to predict the kinetic coagulation process by clotting activity of bacterial endopeptidases

Abstract

A physical-mathematical model was used to evaluate the capability of an enzymatic poolof Bacillus sp. P7 (isolated from Piaractus mesopotamicus) to promote the bovine caseinmicelles coagulation. Experiments were designed to assess the effects of temperature, pH,and enzyme activity/mass of substrate ratio on the kinetic parameters of the coagulationprocess and the microstructure of the obtained clots. Descriptive and predictive equationsindicate that the temperature and the pH modified these parameters significantly. Inoptimal conditions, the clot?s mean pore size was 3.6 times smaller using chymosin. Onthe other hand, rheological measurements evidence a moderate elasticity of clot, whichindicates the usefulness of P7 protease preparation as a clotting agent in spreadable orsoft cheese manufacture. Also, the hydrolysis products, which are in the whey after caseinmicelles coagulation, demonstrated antioxidant activities. Equations to model and predictthe process kinetics were combined with rheological and microstructure analyses of theobtained clots, and whey bioactivities were evaluated. Nevertheless, the use of P7PPrequires further investigation concerning the stability of the enzyme preparation duringstorage, its performance, and how these variables could be related to the proposed models.