PHYLLOQUINONE (VITAMIN K-1) IN CEREAL PRODUCTS

The significance of cereals as dietary sources of phylloquinone (vitam in K-1) was estimated by analyzing the phylloquinone content in some r epresentatives of milling and bakery products commercially available i n Finland. For extraction of phylloquinone, two procedures were compar ed. Routine determinations were made by isopropanol-hexane extraction. After purification of the extracts with semipreparative straight-phas e HPLC, phylloquinone was quantified by reverse-phase HPLC with dual-e lectrode electrochemical (EC) detection. Menaquinone-4 (MK-4) was used as an internal standard. The phylloquinone content of some fat-contai ning bakery products were, however, quantified by the external standar d method. The highest phylloquinone content was found in doughnuts (8. 5 mu g/ 100 g), while the phylloquinone content of other bakery produc ts varied at 3-5 mu g/ 100 g. Among milling products, the best source of phylloquinone was rye meal (5.9 mu g/100 g). The phylloquinone cont ent of the other milling products, except whole wheat flour (4.0 mu g/ 100 g), was very low (<3 mu g/100 g). Due to this low phylloquinone co ntent, cereal products cannot be regarded as significant sources of vi tamin K, despite their overall significance in diets. The contribution to the average daily dietary intake of vitamin K in Finland was estim ated to be approximate to 6 mu g, which is 7-10% of the recommended da ily intake.