Apple belongs to Rosaceae family. Botanical name of apple is Malus pumila. Phenolic compounds and vitamin C in apple makes it a significant source of anti oxidants. Apple is ranked second for the concentration of phenolic compounds among all other fruits15.The phenolic compounds that can be isolated from apple ranges from 110 to 357 mg/100 g 16,17. Anthocyanins, quercetin, catechin, and chlorogenic acid are the phenolic compounds found in apple. Compounds found in apple peel are procyanidins, catechin, epicatechin, chlorogenic acid, ploridizin, and the quercetin conjugates.Chlorogenic acid is rich in flesh of apple when compared to the peel of apple18.
Apple contains vitamins,minerals and high amount of soluble fibre. This soluble fibre lowers blood cholesterol level. Recent studies reveals the relationship between phenolic compounds and reduced risk of diseases19.Therefore consumption of apple prevents the damage of cells from oxidative stress and also from several diseases.
Punica granatum is the botanical name of pomegranate and it belongs to family called Punicaceae. It contains bio active compounds like tannins and phenolics. Various parts pomegranate fruit including peel are used to treat inflammation, fever, bronchitis, diarrhea, dysentery, vaginitis, urinary tract infection20,21. Low density lipoprotein is protected by polyphenols from cell mediated oxidation by interacting directly with lipoprotein and indirectly by accumulating in arterial macrophage. Hence they have anti- atherosclerotic activity. Antihypertensive effect of pomegranate decreases angiotensin-converting enzyme (ACE) activity22. Due to biological actions pomegranate juice has become more popular (Lansky et al., 1998). Thus, the antioxidant and antitumoral activity of pomegranate bark tannins (punicacortein) (Kashiwada et al., 1992; Su et al., 1988) and the antioxidant activity of the fermented pomegranate juice (Schubert et al., 1999) have been reported23,24,25.
ANTI OXIDANTS OF VEGETABLES:
Beetroot contains phenolic content of 50-60 ?mol/g of its dry weight due to which it ranks 10 among most powerful vegetable with respect to anti oxidant activity26Betalains are water soluble nitrogenous pigments which have two main groups called as the red betacyanins and the yellow betaxanthins. Beetroot is a rich source of betalains. Betalains prevents the free radical induced oxidation of biological molecules as they are free radical scavengers27. In modern food industry betalains are used extensively because they are one of important natural colorants that were developed in earlier times28. Other than betalains beetroot also contains phenolic acid and folic acid. Phenolic acids that are found in significant amount in beetroot are ferulic, protocatechuic, vanillic, p-coumaric, p-hydroxybenxoi, and syringic acids. Folic acid constitutes about 15.8 mg/g of dry weight of beetroot29.
Carrot is a root vegetable which is not only rich in bioactive compounds but also micronutrients,minerals and anti oxidants like carotenoids and phytophenols30.High levels of phytochemicals in fruits and vegetables prevents chronic diseases that are closely related to oxidative stress of human body31.High concentration of bioactive constituents in carrot makes it one of the most important horticultural crop32.Calcium ,iron, magnesium, phosphorus and carbohydrates are rich in carrots33.In order to prevent chronic diseases like cancer,cardiovascular disease and diabetes vitamins, provitamins and phytochemicals are required which are rich in fruits and vegetables34.
The fruits and vegetables described in this review indicate the importance of antioxidants and their nutritional importance. Researches are being conducted in this field to know more about these antioxidative fruits and their contribution in preventing early onset of disorders like myocardial infaction, hypoxic ischaemia, coronary heart disease, atherosclerosis, erectile dysfunction in males.