Production and nutritional evaluation of cookies blended from sorghum, cowpea, plantain and sweet potato

Abstract

This study was carried out to produce and evaluate the nutritional quality of cookies formulated from sorghum and fortified with cowpea, plantain and sweet potato. The sorghum and cowpea were subjected to processing technique of sprouting while plantain and sweet potato was peeled oven dried at 45°C. The sorghum variety used was Chakalari white, a low tannin variety, cowpea (Borno red), plantain (unripe) and sweet potato (Yellow variety). Sorghum (60%) was supplemented with legume and tubers at varying proportions: five formulations were made. The parameters assayed include proximate composition, mineral element, in-vitro protein digestibility, vitamin and tannin content, using standard methods. The result showed a significant protein yield for sorghum 60: Cowpea 40 fortification (12.82±0.00) when compared with the control (unprocessed) (5.07±0.00) and the processed samples at (p<0.05). Increases in moisture, crude protein, and crude fiber content in the formulated cookies were observed. Carbohydrate content of the cookies increased as the level of cowpea flour decreased by 10%. The result showed a percentage increase in the in-vitro protein digestibility of processed samples with cowpea having the maximum level (91.90)% at 6 h digestibility. For the mineral element, there was an increase in Ca and K. For the vitamin content a significant increase was observed in the level of vitamin B6 of processed samples and formulated cookies compared to control. The tannin content of processed sample (1.54%) significantly decreased compared to unprocessed sample (control) 2.07%. The sensory evaluation revealed that SSSC and SSDSp were more acceptable than the other ratio blends. It can be concluded that the nutritional quality of the cookies were improved with the addition of cowpea. Sample with sorghum: cowpea (60:40) is a better option for cookies, as it is more superior in nutrient analysis compared to the remaining ratios. Key words: Sorghum, cowpea, plantain, sweet potato, cookies.