Phytochemical Contents and Antioxidant potentials of Eggplants from Kano State, Nigeria: A Review

Abstract

Fruits and vegetables are considered as good source of functional foods due to their health benefits and nutritional content. Dietary constituents of fruits and vegetable are commonly available and has significant application in management of chronic diseases such as; coronary heart disease, stroke, cancer and diabetes, many medicinal purposes, control of excess weight and obesity due to high fiber content present. Many phenolic compounds had been identified in garden eggplant such as; catechin, rutin, naringin, naringenin, syringic acid, chlorogenic acid, caffeic acid, p-coumaric acid, sinapic acid and anthocyanin. Health-conscious consumers generally focus on the antioxidant capacity, and the phenolic content, vitamins, carotenoids and phytochemicals. All varieties of garden egg vary in polyphenol endowed with antioxidant activity. Polyphenolic compounds and antioxidant activity in eggplants which depend on the cultivar, maturity stage and parts of the fruit. Growing conditions are also reported to significantly affect the phenolic contents. This review discussed the polyphenolic contents and antioxidant activities of different eggplant cultivars. Priority was given to green, white and dark-purple cultivars which are commonly grown in Nigeria. White and green eggplants possess higher phenolic contents when compared with dark purple eggplant which possesses higher antioxidant capacity. They contain about 92% water, 5% protein, copper (0.62mg/100g), magnesium (81.69mg/100g), potassium (87.22mg/100g), sodium (32.51mg/100g), irons (31.41mg/100g), zinc (1.41mg/100g), carbohydrate (7.2 g/100g), fibers (2.0g/100g), calcium (28 mg/100g), iron (1.5 mg/100g) and considerable amount of beta carotene (0.35 mg/100g), ascorbic acid (8 mg/100g), riboflavin (0.06 mg/100g) and thiamin (0.07 mg/100g). The species of African eggplant have nutritional and therapeutic values and can be used in the development of functional foods and these bioactive compounds are responsible for high functions of eggplants and provide antibacterial, anti-inflammatory, anti-allergic, hepatoprotective, antithrombotic, antiviral, anti-carcinogenic and vasodilatory properties in humans.