Food folate assay with protease, alpha-amylase, and folate conjugase treatments.

摘要

The effects of protease, alpha-amylase and folate conjugase treatments on apparent folate content were examined in 4 food composites designed to be low in folate (31.2μg/day calculated according to previously published food folate tables) for the determination of folate requirements in man. Protease and alpha-amylase treatments were performed for 16 and 4 h, respectively, at pH 4.1 and chicken pancreas folate conjugase (FC) for 3 h at 37 deg C. Folate was determined by microbiological assay using theLactobacillus casei method. Mean folate content in these menus was 56μg/day after treatment with FC alone. However, means were 90μg/day with protease and FC, 126μg/day with alpha-amylase and FC, and 152μg/day with alpha-amylase, protease and FC treatments. Tri-enzyme treatment seems to be essential to estimate food folate content accurately. Food folate tables should be revised using these enzyme treatments to accurately establish the dietary folate requirements in man.