FOOD FOLATE ASSAY WITH PROTEASE, ALPHA-AMYLASE, AND FOLATE CONJUGASE TREATMENTS

We evaluated the effect of protease, alpha-amylase, and folate conjuga se treatments on apparent folate content in four food composites desig ned to be low in folate (31.2 mu g/day calculated according to previou sly published food folate tables) for the determination of folate requ irements in humans. Protease and alpha-amylase treatments were perform ed for 16 and 4 h, respectively, at pH 4.1 and chicken pancreas folate conjugase (FC) for 3 h at 37 degrees C. Folate was determined by micr obiological assay using the Lactobacillus casei method. Mean folate co ntent in these menus was 56 mu g/day after treatment with FC alone. Ho wever, means were 90 mu g/day with protease and FC, 126 mu g/day with alpha-amylase and FC, and 152 mu g/day with alpha-amylase, protease, a nd FC treatments. Tri-enzyme treatment appears to be essential to dete rmine food folate content accurately. Food folate tables should be rev ised using these enzyme treatments to accurately establish the dietary folate requirements in humans.