73C-9 |
Casein proteolysis during salt distribution in cheese at different temperatures |
A. C. RUBIOLO and G. A. Sihufe. Grupo de Ingeniería en Alimentos y Biotecnología, INTEC (U.N.L - CONICET), Güemes 3450, Güemes 3450, 3000 - Santa Fe, 3000, Argentina Sodium Chloride is one of the most used food additives. The food industry has responded to dietary needs by providing processed foods with reduced amounts of sodium or using sodium substitutes. In the case of cheese the quantity of NaCl affects quality of the final product, however KCl can be successfully used as a partial salt substitute. The rate of casein degradation is dependent on the salt concentration. The diffusion and distribution of salt are achieved during brining and ripening and can be calculated by diffusion model in cheese. Therefore, effects in the evolution of the casein hydrolysis can be studied. The objective was to determine the relationship between the as1-casein hydrolysis and the salt concentration when the cheese is salted with a mixture of NaCl and KCl. A mathematical model was used to calculate the salt concentration after salting, and the average salt in different zones during distribution in cheese. The relationship between as1 - casein hydrolysis and the salt concentration was determined with experimental data obtained at specific temperature for salting with a mixture of NaCl and KCl and connected with the program for calculating the protein transformed according the composition in cheese. Average salt concentrations and percentage of proteolysis were studied for several cases at 12 °C salting temperature and three ripening temperatures: 5, 12 and 16 °C. Different NaCl and KCl concentrations in cheese portions showed changes in as1-casein hydrolyzed but the difference of proteolysis rate between external and internal zones is similar at those temperatures. The average relative error between experimental and theoretical values was 7 % when the ripening temperature was 12 °C. These results can be useful to determine better sampling times according to the temperature in order to reach a pre-defined casein degradation during the ripening of cheese.
Session 73C, Food Engineering: Transport Processes and Kinetics
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