BLOCK FREEZE CONCENTRATION AS A TECHNIQUE AIMING THE GOAT MILK CONCENTRATION: FATE OF PHYSICAL, CHEMICAL, AND RHEOLOGICAL PROPERTIES

In the face of the results scarcity for the goat milk processing using emerging and innovative technologies, the results obtained in the present study are relevant, and may in the future be extremely important for goat milk industry. Therefore, block freeze concentration technique was used to concentrate skim goat milk until three stages. The effects of freeze concentration on skim goat milk properties were evaluated by the analysis of total solids content, lactose content, total protein content, casein content, whey protein content, mineral content, and density. The color parameters of concentrate and ice fractions were also evaluated according to the CIELab color scale, and according to the rheological parameters. As the freeze concentration stages progressed, the total solids content, total protein, casein, and whey protein contents increased in both concentrate and ice fractions. In all stages, it was possible to note that the lactose content showed an equilibrium between both fractions. The densities values of both fractions also increased by increasing of the freeze concentration stages. Block freeze concentration obtained concentrates from skim goat milk with a whiteness index similar to whole milk. Overall, all concentrate and ice fractions showed tendency a greenish and yellowish color. The transition from Newtonian to non-Newtonian behavior was observed for concentrates and ices from second and third stages, respectively. Power Law and Herschel-Buckley models fitted to describe the behavior of the flow of all concentrate and ice fractions. The results generated in this study showed that concentrates from stage 1 and 2 demonstrated a promising product to be used by dairy industries.