METHOD FOR DETECTING BACTERICIDAL ACTIVITY OF MILK Russian patent published in 2004 - IPC

FIELD: biochemistry.

SUBSTANCE: the present innovation deals with milk biochemistry and methods to evaluate the capacity of milk biologically active substances to inhibit the growth of microflora, Escherichia coli, in particular. The method deals with evaluating the growth of E. coli test culture upon beef-extract broth (BEB) supplemented with whey according to altered values of optic density. One should prepare milk whey out of milk sample of 50 cu. cm volume by adding 10%-sulfuric acid solution till obtaining a casein clot to be further removed due to filtration followed by restoration of medium reaction up to pH = 6 by multi-purpose indicator. One should add whey and E. coli test culture at optical density of 0.45-0.55 by PEC at red-color light filter (wave length being 550 nm) into BEB. One should evaluate bactericidal activity of milk by BEB's optical density by adding E. coli test culture and tested whey as compared with BEB's optical density and test culture without addition of tested whey at thermostating for 24 h at 38 ± 1 C followed by calculations according to certain formulas. The innovation enables to objectively evaluate milk capacity to inhibit the growth of E. coli.

EFFECT: higher efficiency of detection.

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