DETERMINATION OF FOLIC-ACID CONTENT IN FOODS OF ANIMAL ORIGIN BY MEANS OF HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY (HPLC)

The folic acid content of food of animal origin was determined by means of high-performance liquid chromatography (HPLC). Free folate (monoglutamate forms) and total folate (monoglutamate + polyglutamate forms) were differentiated. Liver (bovine 963, hog 136 mug/100 g) and kidney (bovine 410, hog 93 mug/100 g) contained the highest content of total folate, followed by egg (67 mug/100 g), soft cheese (44-62 mug/100 g), milk and other dairy products (3 28 mug/100 g). Chicken, fish, beef and pork contained only a low content of total folate (112 mug/100 g). The free folate portion ranged from 14.7 to 100% (mean 69.2%). The main folate derivatives tetrahydrofolic acid (THF), 5-methyl-THF and 5-formyl-THF showed the following distribution. In milk and milk products the mean was 70% for 5-formyl-THF, 20% for 5-methyl-THF and 10% for THF; in the other products the three derivatives were distributed about equally but the range of variation was high.