The parameters selection for separating freezing-out for extracting the components from curd whey

Abstract

Curd whey is a valuable secondary raw material of the dairy industry. Most of the whey is drained as a waste product, which causes not only economic but also environmental damage. Therefore, the effective technologies development for the curd whey processing is the dairy industry actual task. The present work purpose is to select the effective modes of the whey freezing-out for extracting its valuable components. In experimental studies, the capacitive type cryoconcentrator was used, in which ice is frozen on the inner cylindrical surface. Experiments were made on curd whey separating freezing-out at the crystallizer heat-exchange surface different temperatures. It was found that with a decrease in the freezing rate the loss of dry substances decreases and the cryoconcentration process is more efficient. The protein precipitate is observed during the process of whey freezing-out at the bottom of the crystallizer. This phenomenon was studied and the additional experiments were made in order to select the most favorable modes. It was found that the protein precipitate largest amount is observed at 1.5 degrees temperature differential and the heat-exchange surface temperature is minus 2°C. Under indicated modes about 2.0-2.1 g/100 g of protein precipitate falls at the bottom of the container.