CARACTERIZAÇÃO DO SORO DE LEITE DE BÚFALA: IDENTIFICAÇÃO DAS PROTEÍNAS E PRODUÇÃO DE HIDROLISADOS COM MÉDIO E ALTO GRAU DE HIDRÓLISE

Buffalo milk represents 12% of world production of milk, with high protein and fat content of the cow. The whey is the co-product of cheese industry that has been often discarded into the environment, causing great environmental impact due to its rich protein and lactose constitution. Enzymatic hydrolysis is an important technological advance to improve the physical, chemical and functional properties of these proteins. The objective of this research was to produce protein hydrolysates from whey proteins present in buffalo milk and to simulate the digestion in vitro by the method of dialyzability. The whey was dialyzed to remove lactose and small peptides and amino acids, and treated with kaolin for fat adsorption. The partial and total hydrolysates were obtained by the action of pepsin, trypsin, chymotrypsin and carboxypeptidase A in specific pH and temperature, added to the whey together or separately at different times of hydrolysis. Quantitation of proteins, amino acids, lactose and fat were performed according to Bradford (1976), HPLC, Miller (1959) and Gerber respectively. The qualitative characterization of proteins and hydrolysis products was made by PAGE and SDS-PAGE. Tests of absorption of hydrolysis products were performed in vitro by dialyzability. The results for dialyzed and defatted whey was 6.53 g prot L, reduction of 99% lactose and <0.10% fat. Protein bands with relative migration (Rm) similar to bovine whey were observed in SDS-PAGE. However, buffalo whey showed a protein band with Rm 0.73 that is not found in the bovine. The α-lactalbumin and β-lactoglobulin were the most resistant to hydrolysis prolonged; however, with longer times of hydrolysis occurred increase in peptides of low molecular weight and amino acids. The whey also proved to be a source of essential amino acids, such as leucine, lysine, phenylalanine, histidine, threonine and arginine.The relative concentration of amino acids for the dialyzable not hydrolyzed whey buffalo, medium and high degree of hydrolysis were , 4448.516 nM, 4548.052 nM e 4735.373 nM respectively. The whey of buffalo milk contains significant amount of protein available that can be used as a supplemental food or with technological purposes with a high concentration of essential amino acids.