Biochemical, nutritional, and health-promoting characteristics of amahewu along production stages

Fermentation induces a range of transformations in food products; therefore, understanding these changes is essential. This study examines the changes that occur during the production of amahewu from white and yellow maize, utilizing malted sorghum as the inoculum, with a focus on pH, titratable acidity (TTA), total soluble solids (TSS), organic acids, minerals, and phenolic compounds at various stages of production. The results revealed a significant decline in pH, from 5.9 to 3.5 in white maize and from 5.8 to 3.4 in yellow maize, accompanied by a concurrent increase in TSS and TTA in both maize types. Shikimic acid (0.0036–2.56 mg/g) and ferulic acid (19.35–425.43 µg/g) were the most consistently detected organic and phenolic acids, respectively, occurring in all treatments of both white and yellow maize, including raw, cooked, inoculated, and final amahewu product. Shikimic acid levels decreased throughout production (from 2.56 ± 0.09 mg/g in raw white maize to 0.34 mg/g in white maize amahewu and from 0.022 mg/g in raw yellow maize to 0.0036 ± mg/g in cooked yellow maize), while ferulic acid levels fluctuated with an increase-decrease trend. In yellow maize, for example, ferulic acid levels exhibited a fluctuating increase–decrease pattern during processing, ultimately declining from 425.43 µg/g in the raw material to 105.86 µg/g in the final product. Among the minerals, potassium, phosphorus, and magnesium were the most abundant in both maize types, and their levels declined after cooking, followed by increases during inoculation and fermentation. These findings highlight subtle differences between yellow and white maize and their resultant amahewu products. Overall, this study provides valuable insights into the physicochemical properties and composition of amahewu at various production stages, serving as a valuable reference for refining amahewu production, guiding improvements from formulation to quality, and informing potential alterations to create a better product.