Comparison of Nutritional and Anti-Nutritional Qualities of Grewia forbesii Hav. Ex Mast and Grewia bicolor Juss Fruits from Kitapilimwa Forest Reserve in Iringa District

Abstract

The Grewia forbesii and Grewia bicolor fruits were collected from Kitapilimwa Forest Reserve and were analysed for proximate, nutrients and anti-nutrients compositions. Results showed low moisture contents in G. forbesii and G. bicolor amounting to 14.14 and 13.98 percent, respectively. Crude fibre percent was slightly higher in G. bicolor (33.15%) than G. forbesii (31.95%). Lipid content was slightly higher in G. bicolor (1.37%) compared to G. forbesii (1.28%). The crude protein content of G. forbesii (7.44%) was slightly higher than G. bicolor (7.00%). Total carbohydrate content of G. forbesii (68.9%) was higher than that of G. bicolor (70%). Mineral analysis indicated substantial amounts of potassium 898 mg/100 g in G. forbesii and 879 mg/100 g in G. bicolor. Calcium content was high in G. forbesii and G. bicolor amounting to 453 mg/100 g and 582 mg/100 g, respectively. Iron was high in both species (20.73–24.45 mg/100 g). Manganese, copper and zinc were substantially low. The results revealed low levels of tannin (< 1.7%) and phylates (< 0.3%). The presence of substantial amounts of nutrients and low anti-nutrients revealed that the studied species may be potential sources of nutritional food.

Keywords: Proximate analysis, mineral nutrients, anti-nutritional qualities, Grewia species, Kitapilimwa Forest Reserve