Submitted to: Functional Foods
Publication Type: Book / Chapter
Publication Acceptance Date: September 30, 2005
Publication Date: May 1, 2006
Citation: Wang, S.Y. 2006. Fruits with high antioxidant activity as functional foods. Functional Foods. PP. 371-413. Technical Abstract: Fruits have been shown to contain high levels of antioxidant compounds such as carotenoids, vitamins, phenols, flavonoids, dietary glutathionine, and endogenous metabolites. These antioxidants are capable of performing a number of functions including acting as free radical scavengers, peroxide decomposers, singlet and triplet oxygen quenchers, enzyme inhibitors, and synergists. Active oxygen species are generated as by-products of normal metabolism. Increased levels of these active oxygen species or free radicals create oxidative stress, which leads to a variety of biochemical and physiological injuries often resulting in impairment of metabolism, and eventually cell death. There is little doubt that successful prevention of free radical activities will be the key to controlling morbidity and mortality from chronic diseases affecting humankind. The different antioxidant components found in fruits provide protection against harmful free radicals and have been associated with lower incidence and mortality rates of cancer and heart disease, in addition to a number of other health benefits. This book chapter summarizes the dietary antioxidants in fruits, antioxidant enzymes of fruits, antioxidant capacities of various fruits, and the factors which affect their antioxidant activities such as crop genotype variation and maturity, pre-harvest conditions, post-harvest handling and processing. Many attractive opportunities exist for enhancing the quantity and quality of essential nutrients present in fruits. This chapter also discusses some strategies for establishing a new research and production paradigm including: (a) variety selection, molecular genetic breeding and maturity determination at time of harvest; (b) investigation of the influence of production practices on the formation of selected phytonutrient compounds; and (c) evaluation of post-harvest conditions of transport, storage and processing techniques on the stability of phytonutrient compounds in fruits. Knowledge gained from these research studies will be helpful in improving human health by optimizing the nutritional content and quality of fruits in the diet.