Microbiological Assay of Folic Acid Content in Some Selected Bangladeshi Food Stuffs

Folic acid concentration in six common food samples of Bangladesh including lentil (Lens culinaris Medik) and bengal gram(Cicer arietinum), representatives of legumes; spinach (Spinacia oleracea) and basil (Ocimum basilicum), representatives of green leafy vegetables; milk, representative of a common animal source food and topa boro rice (Oryza sativa), a representative of cereal-grains were measured in the present study by microbiological assay using a new trienzyme folic acid extraction method. In this experiment, we estimated that, lentil, bengal gram, spinach, basil, milk and topa boro rice contained about 63 µg, 48 µg, 195 µg, 131 µg,10 µg and 42 µg of folic acid per 100 g of food sample respectively. For the assay of this water-soluble vitamin, Lactobacillus casei (ATCC 7469) was employed as test organism. Trienzyme treatment was performed to release bound folic acid using protease, and a-amylase with chicken pancreases as the conjugase. The highest folic acid content was recorded for spinach (Spinacia oleracea), the well-known richest source of folic acid, followed by basil (Ocimum basilicum). The lowest value was recorded for milk. Topa boro rice, a kind of parboiled rice was also found to be a fair source of folic acid. For these six types of Bangladeshi foods studied, the content of folic acid ranged from 10 to 195 µg/ 100 g, indicating a very wide range of folic acid content in foods.