Effect of boiling, steaming, stir-frying and microwave cooking on the antioxidant potential of peppers of varying pungency

Abstract

The effect of microwave cooking, steaming, stir-frying and boiling on the antioxidant potential of bell peppers (red and green), jalapeno, cayenne, serrano and habanero peppers was investigated. Antioxidant potential was measured employing two techniques: FRAP and DPPH, and the values reported based on dry matter content. Microwaving increased the antioxidant potential of all peppers studied 2 to 10 times above corresponding raw samples. Stir-frying and steaming resulted in enhancement of the antioxidant concentrations of peppers (1.4–3 and 1.6 − 7.3 times, respectively) above raw samples except steamed red bell peppers and stir-fried habanero peppers which yielded values below raw samples. Boiling resulted in a decrease in the antioxidant concentration of most peppers except those with medium pungency (jalapeno and serrano), which yielded values two and four times above raw samples, respectively. All cooked peppers showed an increase in antiradical activity (1.1–8.9 times) above raw samples, except boiled bell peppers (green) and cayenne peppers, which showed antiradical activities of 1.0 and 0.7 respectively below the raw samples. Our findings suggest that cooking most peppers with techniques such as microwave cooking and stir-frying that involve no addition of water may be a better way to prepare them as this generally increases the antioxidant potential of the peppers.