THE RESEARCH OF THE TYPES OF MOISTURE BONDS IN PROTEIN-CARBOHYDRATE CONCENTRATES OF CHEESE WHEY

Abstract

The purpose of the research is to improve the technology of producing cheese whey proteincarbohydrate concentrates, in terms of binding moisture with the main components. Objects of the research were natural cheese whey obtained in the production of Rossiyskii cheese and ultrafiltration cheese whey concentrates with protein dry matter percentage of 35 and 55%, produced with the use of MMS Swissflow UF industrial ultrafiltration unit with ceramic membranes. The chemical composition and Physico-chemical properties of raw materials and the finished product have been studied using standard methods. Three stages of sample dehydration have been identified. They conform to moisture release with different bonds and energy. Stage I is the production area where unbound moisture is heated and removed, and water molecules are held by weak capillary forces. Stage II is the production area for immobilized moisture removal. Stage III is the production area for chemically bound water removal, which conforms to the residual moisture after drying the sample. An increase in the least mobile water and a change in the ratio between different types of moisturebinding have been observed with an increase in the protein mass fraction in the dry matter of the samples. It has been found that the Maillard reaction occurred in cheese whey concentrates with protein dry matter percentage of 35 and 55% at the temperatures above 78 and 70 °C, respectively. The temperature range of the unbound moisture release was increasing during the drying process due to an increase of the protein content in concentrates as well as the rate of interaction between proteins and lactose leading to non-enzymatic browning of dry products. It has been established that drying cheese whey protein-carbohydrate concentrates with protein dry matter percentage of 35, and 55% is inexpedient at temperatures exciding 130 and 173 °C, respectively.