CONCENTRATION OF AMINO ACIDS OF COTTAGE CHEESE WHEY ON CERAMIC MEMBRANES

Abstract

Research of the process of concentration of amino acids of fresh cottage cheese whey produced by the Peasant (farm) holding of Anikyev A.V. (Polevskoy city of the Sverdlovsk region) is conducted by the method of ultrafiltration on a laboratory (pilot) machine which includes a module with cylinder ceramic membranes on the basis of titanium dioxide of anatase modification in the number of 14 elements, with an applied selective layer of aluminium α-oxide with pores sized 0,01 μm, and total area of membranes sized 3,34 m2, produced by the RPE “Ceramicfilter” Co.Ltd. (Moscow). Chemical composition of the cottage cheese whey is determined preliminary, before the concentration: the content of protein is at the level of 1 %, lactose – 4,3 %, fat – 0,5 %, mineral matters – 0,7 %. In the process of ultrafiltration on ceramic membranes, protein got concentrated
in 9,8 times, at that weight fraction of protein in the solution amounted 0,18 %, in sediment – 0,72 %. Average selective ability of CUFE (Ceramic Ultrafiltration Filtering Element) membranes – 19 on proteins of cottage cheese whey is at the level of 97 %. Initial solution of the whey contained 176,67 mg/l, after the concentration – 279 mg/l, which is 58 % higher. A part of amino acids transferred to sediment was not considered during calculations. The largest weight fraction in the initial solution compose: glutamic (57,07 mg/l) and asparagine (19,26 mg/l) amino acids, lysine (25,16 mg/l), proline (10,02 mg/l), taurine (9,13 mg/l). It is stated that the largest weight fraction in a concentrate of whey proteins in the end solution compose aspargine (24,19 mg/l) and glutamic (65,34 mg/l) amino acids; significantly increases the amount of lysine (from 25,16 to 71,59 mg/l), cystine (from 0,12 to 2,11 mg/l) and glycine (from 0,73 to 8,99 mg/l). Coefficients of amino acids’ concentration on CUFE membranes (0,01) are determined. It is stated that the coefficient of concentration of cystine (Mr = 240.3 kDa) equals 18, glycine (Mr = 75.1 kDa) – 12, tyrosine (Mr = 181.2 kDa) – 0,35, and threonine (Mr = 119.1 kDa) – 0,55.