The radical-scavenging activity of vegetables was measured using the 1,1-diphenyl-2-picrylhydrazyl-HPLC method, and the effect of cooking on this activity was determined. The content of ascorbic acid having radical-scavenging activity was highest in burdock among the 18 fresh vegetables tested. In some vegetables, the activity increased in spite of the loss of ascorbic acid content after boiling, while in other vegetables, the activity had decreased after boiling. This decrease may be due to release of the activity from cooked tissue into the cooking water during boiling. Both activity and ascorbic acid content of the vegetables cooked in a microwave were generally higher than in those cooked by boiling.

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Sulfate and taurine are major end products of sulfur-containing amino acid metabolism in mammals including humans, and they are excreted in urine. Average excretions micromol/mg of creatinine) in the morning urine of 58 female college students were: total (free plus ester) sulfate (a). 12.53 +/- 3.85; free sulfate, 11.57 +/- 3.69; taurine, 0.78 +/- 0.53. Ratio of total sulfate and taurine was 10 : 0.6. Regression lines obtained by plotting total sulfate, free sulfate, or total sulfate plus taurine against urea have shown that the former excretions are significantly correlated with urea excretion. Excretion of total sulfate at zero point of urea excretion (b). was 5.30, which corresponded to 42.3% of average excretion (12.53) and was assumed to be derived from dietary sulfate. The difference 7.23 (a - b) seemed to be derived from sulfur-containing amino acids. It was pointed out that the difference of average sulfate excretion and sulfate excretion at zero urea excretion, namely a - b, was appropriate for the metabolic index of sulfur-containing amino acids of the group examined. As free sulfate constituted 92.3% of total sulfate, excretion of ester sulfate was at a constant level, and that of taurine was not significantly correlated with urea excretion, the value of free sulfate corresponding to the value a - b of total sulfate mentioned above seemed to be a reliable and convenient index in the assessment of sulfur-containing amino acid metabolism.