Abstract

Yona Jafo, James Nyalandu and Nagu Bwanamdogo

Horticulture in Tanzania has become a very important sector because the demand for organically produced tropical fruits has dramatically increased worldwide. In this study, organically and conventionally grown mango and pineapple from different origins were analyzed for nutritional variables. Characterization of fruit derivatives was achieved using several variables, namely fruits size and colour, o brix (measurement for the sugar concentration of liquids), titratable acidity, pH, organic acids, free sugars, and minerals. Fruit samples analyzed were: fresh organic mangoes local cultivars ‘Dodo’, ‘Bolibo’, ‘Viringe’, cultivar ‘Tommy Atkins’ and conventionally produced cultivars ‘Kent’, organic and conventional pineapple cultivars ‘Smooth cayenne’. The cultivars and their type of cultivations have shown an influence on the levels of titratable acidity, organic acids, sugars and mineral contents like calcium, potassium, magnesium and manganese. Titratable acidity was higher in organic than conventional mango cultivars. Fructose and glucose contents were 22 and 28% higher in conventional than in organically produced mango fruits, respectively. Conventional pineapple fruits have shown higher fructose and glucose content by 18 and 10% as compared with organic pineapple fruits. Malic and citric acids levels were 30 and 16% higher in conventional than organically grown mango cultivars. Manganese, calcium and magnesium contents were 33, 18 and 12% in organic than conventionally grown pineapple fruit. Organic mango cultivars were shown to have higher contents of phosphorus and potassium by 17 and 6%.