Determination of Vitamin U in Food Plants

Abstract

Vitamin U levels were determined on 26 kinds of food plants well known to be healthy vegetables in Asian or Western countries. Spinach showed the highest level of 45.2 mg/100 g DW followed by Pak-choi (34.3 mg/100 g DW)>kale (23.4 mg/100 g DW)>Sumssukbujaengi (19.8 mg/100 g DW)>leaf mustard (19.6 mg/100 g DW)>bud of aralia (19.3 mg/100 g DW)>broccoli (18.9 mg/kg DW)>asparagus (18.7 mg/100 g DW). Among Korean wild medicinal plants, Sumssukbujaengi showed the highest value followed by Sanmanul (a kind of wild garlic) with the level of 14.4 mg/100 g DW. For Chinese and Western cabbages, the level of vitamin U differed according to the parts of the plant such as core, middle and outside leaves. In both cabbages, level in the middle parts of leaves including midribs was the highest. As stated, the level of vitamin U was dependent on the part of the plant sample. Leaf parts of turnip and white radish showed higher value of 8.5 and 12.5 mg/100 g DW, respectively, than those of roots such as white radish in which levels were in the order of middle (11.3 mg/100 g DW), top (8.5 mg/100 g DW) and bottom (8.5 mg/100 g DW) portions in the white radish. In the analysis of amino acids, we did not find either a distinctive relationship between methionine and vitamin U synthesis or a significant connection between various free amino acids and vitamin U level in food plants.