Antioxidant activities
The free antioxidant activities from skin and pulp were similar, and both were higher than that found in seeds. The sulfurcontaining amino acids were oxidized during the isolation procedures to cysteic acid and methionine sulfone. This could explain lower antioxidant activity in skin compared to the phenolic content in skin. Some antioxidant activity may be lost during double extraction and freeze-dry procedure, or they are not completely released in the analysis and still remained in the solids. The antioxidant activity in the skin was not tremendous high but it was significantly higher than that in seeds and pulp. The bound antioxidant activity in pulp was extremely low suggesting that antioxidants in the pulp were not easy to bing possibly due to pulp structure.
The free antioxidant activity for seeds was about a half compared with the skin and pulp. Extremely lower bound antioxidants were found in pulp. Although the antioxidant activity in seeds was lowest among the 3 components, approximate 49% free antioxidant antivity, 76% bound antioxidant activity, and 58% of total antioxidant activity were contributed by seeds based on its' 66% of the total solids. Thus, the seeds could be a good resource to be utilized for antioxidant antivity.