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.

Keywords:

• antioxidant potential
• microwaving peppers
• boiling peppers
• effect of cooking
• antiradical potential
• FRAP
• DPPH

PUBLIC INTEREST STATEMENT

Peppers are widely consumed globally due to the health benefits that are associated with the substances that they contain. Even though in some instances, the peppers are consumed raw such as in salads, a majority of consumption involves some form of heat treatment. The effect of heat on the beneficial substances in the peppers is a matter of great interest. The present study aims to evaluate the effect of various types of heat applications on the beneficial substances in various types of peppers. Microwave cooking, stir-frying and other heat application methods that do not involve adding much water like boiling are presented as better ways of preparing the peppers for consumption with minimal loss of the beneficial substances.

Competing Interests

The authors declare no competing interests.

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Additional information

Funding

The authors received no direct funding for this research.

Notes on contributors

Nixon O. Mwebi

Nixon Mwebi is a professor of Chemistry and the Chair of the chemistry department at the University of LaVerne since 2018. Before that, he was professor of Chemistry at Jacksonville State University for 13 years. He obtained his PhD in chemistry from University of Maryland College Park, Masters in Chemistry from Hampton University, a bachelor’s degree in Chemistry from Kenyatta University in Nairobi Kenya. He teaches environmental, analytical and food chemistry and conducts research in analytical, environmental, natural products, free radical research, and food chemistry. His food chemistry research focusses on the quality of food from pre to post-harvesting and more especially the impact of preparation and processing on food quality.