Fortified Cereal Innovation: Vitamin Retention, Antinutritional Factors, Physicochemical Properties, and Storage Stability

Abstract

Despite the nutritional advantages of ready-to-eat breakfast cereals, challenges in nutrient retention during processing and storage persist. This study developed 12 nutrient-dense, ready-to-eat breakfast cereal formulations using a mixture centroid augmented design, combining sorghum flour (X₁), soybean flour (X₂), and fruit slurry (1:1 mango and banana pulp) (X₃), all inoculated with Lactobacillus plantarum (NRRL B-787). The mixtures were cold-extruded and then dried at 50°C for 5 h before undergoing analyses for vitamins, antinutritional factors, and physicochemical properties. A special quartic model was used to describe the formulations, and numerical optimization identified the optimal blend based on target nutrient profiles. The storage stability of the optimized formulation was evaluated over 12 weeks at room temperature, in an incubator, and under cold storage conditions. Statistical analysis (Design Expert 11) showed that fruit slurry significantly enhanced vitamins A and C, while soybean flour increased vitamins B1 and B9 (p < 0.05). Antinutritional factors decreased with higher fruit slurry content, whereas sorghum flour increased phytate, oxalate, alkaloid, and tannin levels. Measured physicochemical properties ranged as follows: pH (5.31–6.03), water activity (0.60–0.85), water absorption capacity (116.62%–148.16%), and bulk density (0.29–0.39 g/mL). The quartic model accounted for over 80% of the data variability and was significant for most responses. Storage studies revealed that cold and incubator conditions better preserved vitamin C and carotenoids than ambient storage. These findings support the formulation and storage optimization of nutrient-rich cereals that incorporate sorghum, soybeans, fruit slurry, and probiotics.