Antioxidative properties of bitter gourd (Momordica charantia) and zucchini (Cucurbita pepo)

The enzymatic and non-enzymatic antioxidative capacities of bitter gourd (Momordica charantia) and zucchini (Cucurbita pepo) were investigated in water extracts and chemical buffer extracts. Bitter gourd and zucchini fruits were purchased from a farmer's market and homogenized separately in water and in a native enzyme extraction buffer. Total phenolic compounds, free radical DPPH scavenging activity, SOD activity and glucosidase activity were assayed in the extracts. The average total phenolic compounds recorded in bitter gourd were 13.28 GAE/g fresh weights while in zucchini, the average was 8.67GAE/g fresh weight. This study also found that bitter gourd was 82.05% as effective as ascorbic acid in inhibiting the free radical DPPH while zucchini was 12.19% as effective. The results indicated that bitter gourd was significantly higher in antioxidant content and in -glucosidase activities than zucchini (P<0.05). On the other hand, significantly higher SOD activities were recorded in zucchini than in bitter gourd extracts.