Customized Cooking Methods Enhance Antioxidant, Antiglycemic, and Insulin-Like Properties of Momordica charantia and Moringa oleifera

The current study compares antioxidant activities, total phenolic content (TPC), vitamin C content, and antiglycemic properties of Momordica charantia (small bitter gourd) and Moringa oleifera (drumstick leaves) before and after subjecting to boiling and microwave heating for different durations. Both cooking methods enhanced the antioxidant activity and vitamin C content in the vegetables studied when cooked for five minutes and these properties declined when the cooking time was prolonged to 20 minutes. Cooking also retained or slightly improved the α-glucosidase enzyme inhibition activity of the vegetables; however, it reduced the ability of the vegetable extracts to inhibit α-amylase enzyme activity. The antioxidant activities were positively correlated with the TPC and vitamin C content in the vegetable extracts tested. The present study also evaluated the insulin-like properties (stimulation of adipogenesis) of selected vegetable extracts (five minutes microwaved). 3T3-L1 adipocytes treated with small bitter gourd extract significantly stimulated lipogenesis (in the absence of insulin) compared to drumstick leaves. Thus, the finding of this study negates the belief that cooking will reduce the nutritional value of the vegetables and also suggested that appropriate cooking method and duration for different vegetables could be selected to improve or preserve their nutritional value