Fermentability and nutritional characteristics of sorghum Mahewu supplemented with Bambara groundnut

Abstract: Processing functionality in terms of fermentability and nutritional characteristics of Mahewu (a sorghum-based nonalcoholic beverage product) supplemented with different proportions of Bambara groundnut (BGN) (80:20 and 70:30, respectively) was investigated to develop a sorghum-based beverage product with improved nutritional quality. Sorghum-BGN Mahewu blends showed a rapid reduction in pH and significantly (P < 0.05) lower final pH (4.3) after 24 hr compared to the control (pH 5.1) (100% Sorghum Mahewu). With total titratable acidity (TTA), sorghum–BGN Mahewu blends had significantly higher final TTA (0.7%) than control (0.4%). Sorghum–BGN Mahewu blends had higher protein and crude fiber contents (up to 7.7% and 7.9%, respectively) than control (6.1% and 5.7%, respectively). In general, sorghum Mahewu supplemented with BGN did not show substantial increase in mineral and individual amino acid contents after fermentation compared to the control, possibly due to increase in tannin content with BGN supplementation. Fermentation significantly (P < 0.05) reduced phytate content by more than 90% in sorghum Mahewu supplemented with BGN when compared to the control (28% reduction). Importantly, BGN supplementation improved the level of some essential amino acids such as threonine, methionine, phenylalanine, isoleucine, leucine, histidine, and lysine. Therefore, supplementation with BGN can potentially improve the nutritional quality of sorghum Mahewu but modification in processing procedure is required to effectively improve the nutritional quality of sorghum–BGN blends. Practical Application: This research work has direct application in addressing problem of malnutrition, as well as improving utilization of indigenous food crops in commercial food processing. This is one of the practical approach to address food insecurity that is prevalent in most African countries.