Value addition and fortification of native cereals, legume crops among smallholder farmers in semi-arid areas of Zimbabwe

Abstract

addition and fortification of native cereal based foods with essential micronutrients has been proved to be an effective way of reducing deficiencies in micronutrients at household level and especially in rural communities. Strategies for national fortification usually do not make significant differences in the remotest areas which are not reached by commercially produced foods. The feasibility and sustainability of small scale value addition and fortification as a mechanism to overcome this barrier are not well documented. The main objective of this study was to develop sesame fortified sorghum and pearl millet porridge. A Completely Randomised experimental Design (CRD) was conducted to develop six different formulation combinations of sesame, sorghum and pearl millet. Raw materials used in the formulation of the porridge blends were subjected to proximate analysis to determine the overall macro and micro nutrient composition. The raw materials were roasted at 70 degrees Celsius at varying roasting times of 10 min and 20 minutes in an oven. Combinations of cereal – legume mixtures were mixed in the laboratory to produce six fortified porridge blends which were also analysed for their nutrient content. The porridge blends were also subjected to sensory evaluation to determine the acceptability of the porridge blends to semi trained panellist. Results show that there significant differences (p<0.05) in both macro and micro nutrients between the different formulation combinations of the porridge blends. Cereals had the highest amounts of carbohydrates, while the legumes had high fat and protein content. Significant differences (p<0.05) were also noted on micro nutrients in the raw materials with potassium, calcium and iron topping in micronutrient content. Nutrient analysis of the porridge blends showed significant (p<0.05) variation in amount of protein, fat, moisture and ash. Potassium and calcium were found to be lower than the recommended daily allowance acceptable in diets of 500mg and 400mg while iron and zinc were within the recommended daily allowance of 6.0mg and 5.0mg. Sensory evaluation done on all the porridge blends using the Kruskal-Wallis H test showed that there were statistically significant differences in taste, flavour, appearance and texture between the different porridge formulations. Χ2 (6) = 86.271, p = 0.001 for appearance, χ2 (6) = 146.86, p = 0.001 for taste, χ2 (6) = 221.06, p = 0.001 for flavour, and χ2 (6) = 101.76, p = 0.001 for texture. The highest mean rank for taste was noted on Blend 3 followed by B6 with the least in terms of appearance being the control. Flavour had similar results like taste and appearance while B5 scored highest on texture. Blend B3 (60g Sorghum + 20g Pearl millet + 5g Groundnut + 15g Sesame) which was scoring high on taste, flavour and appearance would be a favourable combination for consumers. A post Hoc test using LSD for the mean scores between the formulations revealed that for appearance blend B2, B4 and the control were significantly different (p<0.05) from the other blend. For taste, B2 was significantly different (p<0.05) than all other blends. Blend B2, B4, B5 and B6 were significantly different (p<0.05) in flavour from the rest of the other blends. B2, B3 and B4 were significantly different (p<0.05) from the rest of the blends on texture. Results show that legumes have higher quantities of macro and micro nutrients compared to cereals and that there was significant contribution of micronutrients from sesame. Sesame can therefore be recommended to be in cooperated in formulation of complementary diets for resource poor small holder farmers. Keywords: Cereals; Fortification; Sensory evaluation; Micro nutrients; Sesame; Legumes.