Effect of processing on the microbiological, proximate, antinutritional and mineral profile of selected yellow cassava varieties and sorghum malt as potential raw materials for alcoholic beverage production

Sorghum and yellow cassava can be regarded as the top two raw materials in the production of value-added food products due to their rich nutritional and food properties. Thus, this study was carried out to study the effect of these processing methods on the microbiological, proximate, antinutritional, and mineral composition of these raw materials. The raw materials involved two cassava varieties and one sorghum variety. Steeping, germination, and malting decreased the aerobic plate count from values of 2.40 × 106 ± 0.22 cfu/g and 1.53 × 106 ± 0.32 cfu/g in the sorghum to values of 2.51 × 103 ± 0.05 cfu/g and 1.21 × 103 ± 0.02 cfu/g respectively (p < 0.05). For both cassava varieties, the values ranged between 5.37 × 104 ± 0.26 cfu/g and 9.40 × 104 ± 0.17 cfu/g in the fresh roots to values of 2.49 × 102 ± 0.35 cfu/g and 1.31 × 102 ± 0.23 cfu/g in the cassava flours. Significant differences were observed for the values (p < 0.05). Malting increased the crude protein to values of 13.51% ± 0.25% and 14.84% ± 0.42% respectively in the sorghum (p < 0.05). Processing of cassava roots into flour reduced the protein content from values of 3.12% ± 0.33% and 3.36% ± 0.15% to 2.20% ± 0.18% and 2.44% ± 0.13% respectively. Steeping, germination, and malting decreased the phytate (from 42.37% ± 0.89% to 7.2% ± 0.28%), oxalate (76.97% ± 1.63% to 20.54% ± 0.92%) and tannin (2.85% ± 0.02% to 0.4% ± 0.02%) (p < 0.05). It was concluded from the results that steeping, germination, malting, milling, and drying could be used singly or in combination as a processing regime to affect the nutritional profile as well as reduce the antinutritional factors of sorghum and cassava which could be utilized as potential raw materials in the provision of nutritious value-added food products especially in alcoholic beverage production.