Optimisation of a Nonalcoholic Malted Beverage (Pyer-kushu) Produced from Blends of Sorghum Varieties Using a Mixture Design Technique

Purpose: Global concern over diet health effects is increasing, especially in Africa, where traditional dishes deeply rooted in cultural practices and beliefs are popular among the population. Thus, the production of a nonalcoholic malted beverage ‘pyer-kushu’ from the blends of sorghum varieties was investigated.
Research Method: A D-optimal mixture design (constraining malted ‘koyanga’ red (MRS) and ‘moskwa’ white (MWS) sorghum to 10–20% each, unmalted ‘koyanga’ red (URS) and ‘moskwa’ white (UWS) to 30–40%) generated 12 formulations. Each formulation was produced via traditional malting and brewing, then analysed for key physicochemical properties, mineral content, microbial load, and sensory qualities (50-member panel hedonic evaluation). Statistical analysis (ANOVA and mixture regression models) identified significant formulation effects and optimal sorghum blend ratios.
Findings and Values: The physicochemical and mineral contents were pH (3.84–5.62), total solid (8.80–19.16%), total soluble solid (5.33–6.06 °Brix), titratable acidity (0.22–0.35%), specific gravity (1.00–1.06), foaming capacity (10.00–40.00%), viscosity (4.68–5.57 cP), sodium (21.00–23.66 mg/100g), calcium (3.60–6.10 mg/100g), manganese (28.66–40.00 mg/100g), iron (5.93–9.13 mg/100g), and phosphorus (2.00–3.66 mg/100g). The total plate count was between 5.9×104 and 1.12×105 cfu/ml. The optimum formulation is 20.00% MRS, 12.90% MWS, 30.00% URS, and 37.10% UWS, achieving high desirability, balanced nutrition, and acceptability. This study provides a scientific approach to improve the nutritional profile and consistency of traditional African beverages, specifically 'pyer-kushu', to combat malnutrition and boost local economies.