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 beta-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 beta-glucosidase activities than zucchini (P<0.05). On the other hand, significantly higher SOD activities were recorded in zucchini than in bitter gourd extracts.