Effect of Fermentation and Sprouting on the Proximate Composition, Anti-nutritional Properties, Minerals Content and Bioavailability of Breakfast Meal Composite from Yellow Maize, Black Kidney Beans, and Date Flours

Abstract

Background: Breakfast plays an important role in maintaining metabolic balance and providing essential nutrients for daily activities. However, cereal-based breakfast foods, particularly those derived from maize, are often nutritionally limited because of their relatively low protein quality and anti-nutritional factors, which may reduce nutrient bioavailability and absorption. Objective: This study evaluated the effects of fermentation and sprouting on the quality attributes of a composite breakfast meal formulated from yellow maize, black kidney beans and date fruit. Methods: Yellow maize grains were subjected to 72 h fermentation and germination/fermentation treatments. Black kidney beans were processed as sprouted or non-sprouted before incorporation into composite flours. Date fruit flour was prepared by drying and milling. Five breakfast meal formulations were developed through material balancing, targeting 16% protein/100 g: FM (fermented maize control), FMSBD (fermented maize + sprouted beans + date), FMNSBD (fermented maize + non-sprouted beans + date), GFMSBD (germinated/fermented maize + sprouted beans + date) and GFMNSBD (germinated/fermented maize + non-sprouted beans + date). Proximate composition, anti-nutritional factors (phytate, oxalate, saponin and tannin), mineral content (calcium, sodium, magnesium, potassium, iron, phosphorus and zinc), and mineral-to-mineral and mineral-to-anti-nutrient ratios were determined using standard analytical methods. Results: Fermentation reduced pH from 6.57 to 3.99 over 96 h, with a corresponding increase in titratable acidity. Proximate analysis showed significant (p < 0.05) improvements in composite samples: crude protein increased from 10.13% (FM) to 35.74% (FMSBD), crude fibre from 4.03% to 6.62%, fat from 4.11% to 10.18% and ash from 1.17% to 5.21%. Anti-nutritional factors were significantly reduced by sprouting and fermentation, with values within permissible limits (phytate: 4.99-12.14 mg/100 g; oxalate: 0.72-4.24 mg/100 g; tannin: 3.06-6.32 mg/100 g; saponin: 0.34-16.17 mg/100 g). Mineral content increased substantially in composite samples, with GFMSBD recording the highest values for calcium (48.37 mg/100 g), magnesium (183.64 mg/100 g), potassium (771.92 mg/100 g), iron (6.82 mg/100 g) and zinc (3.97 mg/100 g). Mineral-to-anti-nutrient ratios indicated favourable bioavailability, with phytate:calcium ratios below the critical threshold (0.20-0.23) in sprouted formulations. Conclusion: Fermentation and sprouting improved the nutritional quality, mineral profile and anti-nutrient reduction of the breakfast meal composite. The GFMSBD formulation (germinated/fermented maize with sprouted black kidney beans and date fruit) consistently exhibited the highest mineral values and favourable bioavailability indices. The developed flour composite has potential as a functional food for improving protein-energy intake and dietary diversity, particularly in developing regions where cereal-based diets predominate.