Total antioxidant capacity in different pea (Pisum sativum) varieties after blanching and freezing

Thirty-five varieties of the green pea (Pisum sativum L.) were analysed for their total antioxidant capacity (TAC). After blanching and freezing, the water-soluble fraction had, on average, a TAC of 0.61(0.22) μmol/g (mean(SD)) and the water-insoluble fraction a value of 0.23(0.08) μmol/g. There was a significant correlation between the TAC in the water-soluble and water-insoluble fractions (r=0.41; p<0.001). The peas had been grown during two consecutive years and were harvested at two different periods during the second year, 1999. Regarding the antioxidant capacity in both the water-soluble and the water-insoluble extract, there was a significant difference between the varieties but not between the harvest periods. A significant correlation (r=0.72) between TAC in the water-soluble fraction and ascorbic acid content was found. Ascorbic acid accounted for a large part of the water-soluble antioxidant capacity. Further studies are necessary to reveal other compounds explaining the variation in pea antioxidant capacity and the mechanisms involved. Measurement of TAC may be a convenient route for the selection of pea varieties with optimal functional and health effects.