Some of the most exciting research in the last decade has been the discovery of a group of nutrients, which have protective eects against cell oxidation. These naturally occurring compounds impart bright colour to fruits and vegetables and act as antioxidants in the body by scavenging harmful free radicals, which are implicated in most degenerative diseases. Epidemiological studies have established a positive correlation between the intake of fruits and vegetables and prevention of diseases like atheroscelerosis, cancer, diabetes, arthritis and also ageing. So pronounced has been their eect on ageing that they have been called`fountains of youth'. Fruits and vegetables have thus had conferred on them the status of`functional foods', capable of promoting good health and preventing or alleviating diseases. Phenolic¯avonoids, lycopene, carotenoids and glucosinolates are among the most thoroughly studied antioxidants. The present review highlights the potential of fruits and vegetables rich in antioxidants, their health bene®ts and the eect of processing on the bioavailability of these nutrients. The paper also reviews some of the important methods used to determine the antioxidant activity.

The anti‐oxidant activity of extracts from 36 vegetables was evaluated by using a model system consisting of β‐carotene and linoleic acid. The total phenolics of the extracts was determined spectrophotometrically according to the Folin–Ciocalteau procedure and ranged from 34 to 400 mg (100 g)−1 on a fresh weight basis. Mint, aonla, black carrots, chenopodium, fenugreek, kachnar and ginger had high phenolic contents. The anti‐oxidant activity expressed as per percent inhibition of oxidation ranged from a high of 92% in turmeric extracts to a low of 12.8% in long melon. Other vegetables found to have high anti‐oxidant activity (>70%) were kachnar, aonla, ginger, fenugreek, mint, beetroot, black carrots, Brussels sprouts, broccoli, lotus stem, yam, coriander and tomato. Anti‐oxidant activity correlated significantly and positively with total phenolics (r2=0.6578, P < 0.05). The results indicate that vegetables containing high phenolics may provide a source of dietary anti‐oxidants.

No abstract

No abstract