Influence of Cooking Methods on Bioactive Compound Content and Antioxidant Activity of Brussels Sprouts

The effects of different cooking methods on total bioactive compound content were determined, and in vitro antioxidant activity in 80% ethanolic extracts of Brussels sprouts was evaluated by spectrophotometric methods. Compared to uncooked, steamed, and microwaved Brussels sprouts extracted with 80% ethanol contained higher amounts of total polyphenols. Uncooked Brussels sprouts contained the highest amounts of total flavonoids. Microwaved Brussels sprouts contained the highest amounts of total carotenoids (0.35 mg/g) and chlorophylls (3.01 mg/g), followed by steamed and uncooked samples. Uncooked fresh Brussels sprouts showed the highest antioxidant activity followed by microwaved and steamed sprouts. Antioxidant activity was measured with the 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and hydroxyl racial scavenging assays as well as the reducing power activity assay, and antioxidant activity was found to increase in a concentration-dependent manner. Based on these results, cooking or heat treatment may decrease antioxidant activities, although their effect on bioactive compound content remains controversial.