FIELD: dairy industry.
SUBSTANCE: method for the preparation of lactose-free milk is carried out as follows. (1) Milk is pasteurized, degreased, and skimmed milk and cream are obtained, which are hydrolyzed with lactase. (2) Enzymatic hydrolysis of skimmed milk by lactase enzyme is carried out. (3) Hydrolyzed skimmed milk is microfiltered (hereinafter – MF), and microfiltration concentrate (hereinafter – MFC) and microfiltration filtrate (hereinafter – MFF) are obtained. (4) MFF is ultrafiltered, and ultrafiltration concentrate (hereinafter – UFC) and ultrafiltration filtrate (hereinafter – UFF) are obtained. (5) The first UFF nanofiltration is carried out, and the first nanofiltration concentrate (hereinafter – NFC1) and the first nanofiltration filtrate (hereinafter – NFF1) are obtained. (6) Then, the second nanofiltration of NFF1 is carried out, and the second nanofiltration concentrate (hereinafter – NFC2) and the second nanofiltration filtrate (hereinafter – NFF2) are obtained. (7) Lactose-free milk is obtained, using optionally at least one of following stages selected from diafiltration, reverse osmosis, chromatography. In this case, the first nanofiltration at the stage (5) is carried out on membranes with a molecular size of 400-600 Da, and the second nanofiltration at the stage (6) is carried out on membranes with a molecular size of 150-250 Da. The final stage (7) is carried out by mixing a composition consisting of UFC, NFC1 and NFF2 and optionally reverse osmosis filtrate (hereinafter – ROF), when the process includes only the reverse osmosis stage performed on NFF2, ROF and salt eluate (hereinafter – SE), when the process includes the reverse osmosis stage performed on NFF2, and the reverse osmosis concentrate (hereinafter – ROC) thus obtained is fed into a chromatographic column eluted by NFF2 to separate SE from sugar eluate (hereinafter – ZE), reverse osmosis salt concentrate (hereinafter – ROSC), reverse osmosis filtrate (hereinafter – ROF') and the second filtrate ROF', while the specified parts of ROSC and ROF' are formed when NFF2 is subjected to chromatography and eluted with NFF2 part with the formation of two chromatographic fractions SE' and ZE', where SE' is subjected to reverse osmosis to obtain ROSC, as well as ROF' and the second ROF' filtrate formed when ZE', in turn, can be concentrated by reverse osmosis with obtaining sugar concentrate (hereinafter – ROZC), hydrolyzed cream obtained at the stage (1).
EFFECT: invention provides for the creation of an innovative multi-stage method for the fractionation of milk, which makes it possible to prepare from the specified fractions a known composition, normal milk or milk with a high protein content and completely lactose-free (<0.01%), which organoleptic characteristics, in particular the degree of sweetness, are similar to properties of corresponding lactose-containing milk.
9 cl, 3 dwg, 5 tbl, 5 ex
