engleski

Optimization of the sweet whey microfiltration

The aim of the present study was to optimize the microfiltration of the sweet whey in order to ensure a maximum microbiological quality in a same range or higher efficiency than thermal processes. Whey is a major by-product of cheese-making and casein manufacture in the dairy industry. Usage of the high temperatures in the whey processing have influence on the structural properties of the proteins, thus resulted with a loss of the immunoactive properties as well as loss of minerals and nutritional value. Microfiltration, often called cold sterilization, enables reduction of viable microorganisms and their spores without usage of the high temperatures. Whey microfiltration was performed at two temperatures (20 and 40°C) and different process parameters in terms of determination of the optimal transmembrane pressure (TMP) and a process yield. In each experiment the flow rate through the membrane was measured. Viable count of microorganisms was determined by the Koch method. Efficiency of the microfiltration was compared with pasteurization at 73°C/20 sec. The best microbial reduction, cca. 3.8 log was achieved at 0.5 TMP and the inlet whey flow of 15 Lh-1. Achieved results were better for cca. 0.4 log than reduction by pasteurization. Used membrane of 0.45µm pore size can achieve an average microbial removal approximately 99.86%.

microbial reduction; microfiltration; whey; process parameters

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