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.

Bambara Groundnut: An Underutilized Leguminous Crop for Global Food Security and Nutrition

“…Typically, the process involves soaking of the whole seeds, followed by dehulling, cooking, and wrapping in banana leaves before fermenting for about 4 days (40). Starter cultures may sometimes be added (44) to enhance the fermentation. The positive impacts of fermentation are a breakdown of the flatus-forming non-digestible oligosaccharides and polysaccharides into digestible simpler carbohydrates and a reduction in ANFs and phenolic content (40).…”

“…Amahewu, or mahewu, is a popular fermented drink traditionally made by fermenting sorghum or maize flour. It is non-alcoholic and is sometimes used as a weaning food (44). However, it is nutrient poor and is often characterized as lacking essential amino acids (67).…”

“…However, it is nutrient poor and is often characterized as lacking essential amino acids (67). Substituting the conventional ingredients with Bambara groundnut reduced phytate content while improving its protein quality and sensory acceptability (44,67).…”

Non-Alcoholic Fermentation of Maize (Zea mays) in Sub-Saharan Africa

“…Increased protein and lysine contents Increased protein digestibility Improved colour, aroma and taste [117] Watermelon pulp powder Increased protein, ash, titratable acidity, vitamin C and total carotenoid contents [118] Ogi Okra seed flour Increased proximate composition (moisture, ash, protein and fat contents) and minerals (iron, calcium and potassium) [119] Defatted and roasted okra seed meal Increased ash, protein and fat contents Higher viscosity and sensory scores for colour and taste [120] Pigeon pea flour Increased protein content and dietary fibre, B complex vitamins and essential amino acids Reduced anti-nutritional factors [121] Whey Increased protein, ash and fat contents and essential amino acids [122] Groundnut seed powder Increased protein, ash and fat contents [123] Other areas that can be investigated to increase the utilisation of maize-based fermented products include the use of whole maize grains, since they furnish desirable health benefits, as well as beneficial components in the products compared to products from processed grains [124,125]. Whole cereal grains contain nutrients such as vitamins, unsaturated fatty acids, dietary fibre and polyphenolic compounds with antioxidant properties that are likely to be cardioprotective.…”

Understanding biodiversity in sorghums to support the development of high value bio-based products in sub-Saharan Africa

“…Sorghum mealie meal can also be fermented to produce a non-alcoholic drink known as Mahewu. This can also be blended with Bambara groundnut to improve its nutritional quality (Qaku et al, 2020).…”