Submitted to: Proceeding Intl Symposium Postharvest Science Technology Horticulture Crops
Publication Type: Proceedings
Publication Acceptance Date: December 26, 2001
Publication Date: January 11, 2002
Citation: Wang, S.Y. 2002. Antioxidant capacity of fruits, vegetables and herbs. Proceeding Intl Symposium Postharvest Science Technology Horticulture Crops. Interpretive Summary: 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 will be the key to controlling morbidity and mortality from chronic diseases affecting humankind. Fruits, vegetables and herbs are good sources of natural antioxidants and have shown a remarkably high scavenging activity toward chemically generated radicals, thus making them effective in inhibiting oxidation of human low-density lipoproteins and preventing various human diseases. However, no review is available on antioxidant capacity of fruits, vegetables and herbs. This review covers both theoretical and practical aspects of antioxidant capacity of fruits, vegetables and herbs and should be useful to a wide range of readers, including students, researchers, plant breeders, health professionals and the general public.
Technical Abstract: Fruits, vegetables and herbs 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. The different antioxidant components found in fruits, vegetables and herbs 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. Many attractive opportunities exist for enhancing the quantity and quality of essential nutrients present in fruits, vegetables and herbs. Therefore, much attention has now been placed on the agricultural practices which will enhance their nutritional content. This paper summarizes the antioxidant capacities of various fruits, vegetables, herbs, and the factors which affect their antioxidant activities such as crop genotype variation and maturity, pre-harvest conditions (climate, temperature, and light), culture practices, post-harvest handling and processing. This paper also suggests some strategies for establishing a new research and production paradigm such as improving selection criteria among different horticultural cultivars, improving pre-harvest conditions and post-harvest handling, and using tissue culture and genetic engineering strategies to enhance nutrient quality.