Nutritional quality and antioxidant activity of mechanically extracted banana juice

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University of Dar es Salaam
This study was carried out to determine banana juice nutritional quality and their influence in vivo for reduction of oxidative free radicals. Five local banana cultivars were used:Mbilabile and Yangambi km 5 (YKM5) banana cultivars collected from Kagera region, Ndeshi and Mlonga from Kilimanjaro region while Pisang Awak (PSA)was from Mbeya. The bunches of bananas were left to ripen to a desired degree of ripeness. The ripe banana fingers were washed, peeled and blended for2 to 10 minutes at 1200 rpm and then squeezed to release banana juice. The juice was frozen stored at -18℃ for further analysis. Nutritional quality of banana juice depended on both cultivars and degree of ripeness (p<0.05). Mineral contents were found to be: Potassium4071 to 17018 mg/l, magnesium 113.08 to 200.10 mg/l, sodium 26.47 to 74.25 mg/l, calcium 6.57 to 36.91 mg/l, zinc 0.95 to 1.95 mg/l and iron 0.19 to 1.40 mg/l. Four analysed organic acids were: malic acid 5.80 to 15.65 g/l,citric acid 2.46 to 6.59 g/l, succinic acid 1.02 to 4.89 g/l and ascorbic acid 0.45 to 1.53 g/l. Mbilabile had the highest malic acid 15.65 g/l, followed byYKM5 13.87 g/l, Ndeshi 13.21g/l, PSA 12.87g/land Mlonga 12.75 g/l.Acid content was affected by ripening process (p<0.05). Beta carotene was not detected in all banana juice, banana pulp and banana spent pulp. Total phenolic content in banana juice in all cultivars ranged from 145.02 to 339.89 mg Gallic Acid Equivalent (GAE)/l. Effectiveness of banana juice to reduce free radicals ranged from 67.20 to 93.49%, while cultivars effectiveness increased in the order of Mbilabile, YKM5, Ndeshi, PSA, and Mlonga. Both total phenolic contents and antioxidant activity depended on cultivars and degree of ripeness. Due to its richness in minerals, vitamins (Vitamin C) and antioxidants, banana juice is a potential source of nutrients. A consumption of 250 ml/daycan supply 50%, 100% and 67% of potassium, vitamin C and free radical inhibition, respectively, of required daily recommended dietary allowance of respective nutrients.
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF TP159.A5T34G47)
mechanically, quality
Gervas, M (2019) Nutritional quality and antioxidant activity of mechanically extracted banana juice, Master dissertation, University of Dar es Salaam. Dar es Salaam.