Abstract
The fermentation potential 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) were investigated to develop a sorghum-based beverage product with improved nutritional quality. Further, consumer acceptability of the sorghum Mahewu blends was determined including shelf stability over 4 weeks at 4°C. Fermentability results showed that sorghum BGN Mahewu blends had 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 Mahewu (0.4%). Sorghum–BGN Mahewu blends had higher protein and crude fibre 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 a substantial increase in mineral and individual amino acid contents after fermentation compared to the control, possibly due to an 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...
M.Sc. (Food Technology)