ADEQUACY OF ENZYMATIC DECONJUGATION IN QUANTIFICATION OF FOLATE IN FOODS

A critical aspect of many assay methods for folate in foods and other biological materials is the enzymatic deconjugation of polyglutamyl forms of the vitamin. This research was conducted to evaluate the properties of pteroylpolyglutamate hydrolase (conjugase) from hog kidney and the efficacy of this enzyme when used to deconjugate sample extracts for folate analysis. Extracts of a variety of foods caused detectable inhibition of the enzyme, although appropriate combinations of incubation time and enzyme concentration yielded complete or nearly complete hydrolysis of synthetic polyglutamyl folates. These results support the efficacy of the enzyme from hog kidney and indicate the need for care in establishing proper conditions for deconjugation in folate assays. © 1990, American Chemical Society. All rights reserved.