Determination of Vitamin B12 and Folate Compounds in Commercially Available Edible Seaweed Products.

Abstract

Information on the contents of both vitamin B12 and folate in edible seaweeds is limited, of which deficiencies disrupt methionine biosynthesis to accumulate homocysteine as a risk factor of cardiovascular diseases. Both vitamins were determined in commercially available edible seaweed products using high-performance liquid chromatography. Dried purple laver (Neopyropia yezoensis) products contain higher levels of vitamin B12 (approximately 30-60 μg/100 g dry weight) and folate compounds (approximately 880-1300 μg/100 g dry weight) than other seaweed products, such as kombu (Saccharina japonica), hijiki (Sargassum fusiformis), and wakame (Undaria pinnatifida). 5-methyltetrahydrofolate was the major folate compound in purple laver products. 5-formyltetrahydrofolate was found at a moderate level, whereas tetrahydrofolate, 5,10-metenyltetrahydrofolate, 10-formyltetrahydrofolate, and folic acid were found to be minor folate compounds. These findings suggest that dried purple laver (nori) products are suitable sources of vitamin B12 and folate compounds for humans, especially vegetarians.