Nutritional Composition and Glycaemic Index of Standardized Traditional Bambara Nut, Corn and Yam-Based Dishes Consumed in the Nsukka Local Government Area of Enugu State, Nigeria

Abstract

Background and objectives: A lack of information on the composition and nutritional impacts of many traditional foods is a major challenge that limits their utilization. This study aimed to determine the nutrient composition and glycaemic indices (GIs) of standardized Bambara nut, corn and yam-based traditional dishes consumed in South-eastern Nigeria. Material(s) and Method(s): Recipes of the dishes were documented from focus group discussions conducted in eight randomly selected communities in the Nsukka LGA, which were further standardized. Nutrient compositions of the prepared dishes were determined using the standard procedure. A serving portion of each dish containing 50 g of available carbohydrates was served to twelve healthy adult subjects. Glucose was used as the reference food. The postprandial blood glucose response of the test and the reference meals were measured over two hours at 30 min intervals. The blood glucose curves were plotted and the area under each curve and the corresponding glycaemic index value for each dish were determined. Data were analysed using Statistical Product for Service Solution (SPSS) software. Analysis of variance was used to compare the means, which were considered significantly different when p#0.05. Result(s): The three traditional dishes were 'okpa' (Bambara nut pudding), 'igbangwu' (corn pudding) and 'ayaraya ji' (coarsely mashed yam with pigeon pea) were included in the study. The dishes had appreciable proximate, vitamin and mineral compositions, although the protein content of the corn and yam-based dishes were low, ranging from 3.4-3.8 g. The vitamin B2 and zinc contents of the dishes were also low. Zinc levels ranged from 0.1-0.4 mg, while the three dishes had equal vitamin B2 contents (0.1 mg). The GIs of the dishes were 51, 54 and 56 for 'igbangwu', 'okpa' and 'ayaraya ji', respectively. Conclusion(s): The dishes had low to medium GI values and thus can be recommended for diabetics, although precautions are needed for 'okpa' and 'ayaraya ji'.Copyright © 2019 G.I. Davidson et al.