Extraction and Assessment Methods as Well as Resources of Natural Antioxidants in Foods and Herbs

Abstract

Antioxidants could scavenge free radicals in the human body, and prevent and treat diseases induced by oxidative stress. In addition, antioxidants could delay the food spoilage, discoloration, and rancidity caused by oxidation in the food industry. Considering that the synthetic antioxidants may have some toxicities and side effects, natural antioxidants from food and medicinal plants could be a better candidate. In addition to the conventional extraction methods, several green and efficient extraction technologies have been developed, such as ultrasonic-assisted extraction, microwave-assisted extraction, enzymatic extraction, and supercritical fluid extraction. In order to comprehensively assess the antioxidant activity of extracts, in vitro and in vivo evaluation methods have been developed. As a result, antioxidant capacities of many foods and medicinal plants have been evaluated, such as vegetables, fruits, cereals, edible macro-fungi, medicinal herbs, flowers, and spices. In this chapter, we summarized the extraction, assessment, and resources of natural antioxidants in foods and medicinal plants, which are very helpful for full utilization of natural antioxidants.