Effects of Different Cooking Methods on the Yield of Carotenoids in Water Convolvulus (Ipomoea aquatica)

Abstract

The effect of microwave, steam, and conventional cooking treatments on the yield of carotenoids in water convolvulus was studied. Each cooking treatment was conducted for 0, 2, 4, 8, and 16 min with two replications. A slight modification of AOAC method was used to determine carotene and xanthophyll content. The mean carotene and xanthophyll contents in fresh raw samples were significantly higher than those of all the cooked samples. Xanthophyll concentrations had greater loss than carotene during cooking. Conventional cooking had lower carotene and xanthophyll content than either microwave or steam cooking. The highest and lowest yields of carotenoids, 86 and 53%, were found in steam and conventional cooking with the heating time 2 and 16 min, respectively.