The Impact of Incremental Alkali Dosages During Nixtamalization on Quality Characteristics of Crunchy Maize Cakes (Akara-Koro)

This study evaluated the impact of nixtamalization on the proximate, functional, phytochemical, mineral, and sensory attributes of Akara-koro, a traditional maize-based snack. Whole maize grains were processed using incremental slaked lime concentrations of 0%, 1%, 2%, and 3%. Proximate analysis revealed that increasing lime concentrations elevated moisture (11.36% to 14.13%), crude protein (9.45% to 11.25%), ash (1.68% to 4.32%), and crude fibre (3.15% to 6.14%), while decreasing fat (4.94% to 3.68%) and carbohydrate contents (69.43% to 60.50%). Functional testing showed concurrent increases in water absorption capacity (169.24 to 175.47 g/ml), bulk density (0.90 to 2.10 g/ml), oil absorption capacity (138.04 to 150.13 g/ml), solubility index (21.78% to 46.77%), and foaming capacity (23.13% to 38.93%), indicating enhanced matrix hydration. Furthermore, alkaline conditioning successfully mitigated anti-nutritional factors, reducing phytates (0.73% to 0.21%), tannins (0.56% to 0.17%), oxalates (3.88% to 2.13%), alkaloids (2.48% to 1.33%), and trypsin inhibitors (3.57% to 1.26%). Mineral profiles were significantly enriched, with calcium increasing from 19.62 to 28.25 mg/100 g, iron from 41.96 to 44.77 mg/100 g, zinc from 23.68 to 26.78 mg/100 g, copper from 2.25 to 8.78 mg/100 g, and sodium from 11.45 to 15.97 mg/100 g. Sensory evaluation indicated that while the unnixtamalized control achieved the highest baseline acceptability scores—color (9.00), aroma (8.30), crispiness (8.20), taste (8.10), flavor (8.00), and overall acceptability (8.50). The nixtamalized treatments scored slightly lower but remained highly acceptable. Ultimately, nixtamalization at 1% to 2% lime concentrations optimizes the nutritional, antinutritional and mineral profile of Akara-koro with minimal sensory degradation, offering a viable processing strategy to fight micronutrient deficiencies in maize-consuming populations. Future research should evaluate the inclusion of natural organic acids (such as citric acid rinses) or traditional spices during the final washing step to neutralize residual alkaline elements, minimizing potential bitter notes while preserving mineral gains.