Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: November 4, 2004
Publication Date: December 3, 2004
Citation: Wang, S.Y. 2004. Antioxidants in fruits and their possible anticancer property. Acta Horticulturae. pp. 36 Interpretive Summary: Fruits contain high levels of antioxidant compounds which are beneficial to human health. However, little information is available on the effects of genetic variation, maturation, and environmental factors on levels of antioxidants in fruits. We have investigated the effect of cultural conditions and post-harvest handling on nutritional content and the ability of fruits to reduce harmful oxygen radicals. In addition, the effectiveness of fruit extracts and bioactive compounds isolated from fruits on the prevention and inhibition of tumor growth are also discussed. We found that the use of compost, mulch, carbon dioxide enhancement or treatment with methyl jasmonate before harvest and various post-harvest handling techniques (such as storage, modified atmosphere packaging, heat treatment and irradiation) increased antioxidant activity and phytonutrients in fruits. We also found that fruit extracts can prevent and inhibit tumor growth. This research increased our knowledge of the impact of culture conditions and post-harvest handlings on nutritional quality of fruit and their anticancer properties. This information will be useful to researchers, plant breeders, and fruit growers interested in selecting the best conditions for maximizing phytonutrient content, antioxidant activity and their anticancer property in fruits.
Technical Abstract: Fruits are good sources of natural antioxidants 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. 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 paper summarizes the 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. Strategies for establishing a new research and production paradigm will be reviewed, such as improving selection criteria among different horticultural cultivars and improving pre-harvest conditions and post-harvest handling to enhance nutrient quality. Evidence will also be presented on the prevention and inhibition of tumor growth by fruit extracts and bioactive compounds isolated from fruits.