Quality Evaluation of Fermented Pre Gelatinized Unripe Plantain and Soybean Based Complementary Foods 1: Physicochemical, Sensory and Rheological Properties

Abstract

Aims: This study aimed at evaluating the effect of the degree (%) of starch gelatinization (G) and fermentation (F) on the physicochemical characteristics of the flours and also the sensory and flow properties of the gruels of unripe plantain fruits and soybean seeds based complementary foods. Study Design: Completely randomized design Place and duration of the Study: This study was carried out in Makurdi, Benue State, Nigeria, between January and November 2023. Methodology: Plantain slices heated to obtain 10% to 100% starch gelatinization were subjected to accelerated natural fermentation followed by drying and milling to yield fermented (F) flours. Non-gelatinized (NG) and nonfermented (NF) lots served as controls. The flours were each combined with soybean flour to obtain 16 g protein/100 g of each mixture based on the proximate compositions of the inputs using material balancing technique. The flours’ oil absorption capacities (OAC), water absorption capacities (WAC), packed bulk densities (PBD), sensory attributes (taste, mouth feel, appearance, overall acceptability) and flow properties of their gruels were evaluated using standard methods. Significant differences and separation of the data means were achieved by Duncan multiple range and Turkey’s tests using an SPSS package, respectively. Results: Gelatinization and fermentation increased WAC and OAC, but decreased packed bulk density (PBD) of the flours with concomitant reduction in pH, viscosities and improved sensory attributes of the gruels. Generally, viscosities increased with increase in slurry concentration and decreased with increase in temperature and shear rates. The flow behavior indices ranged from 0.27 to 0.64, with lower values in gelatinized and fermented samples, showing more pseudoplastic behavior in pretreated samples. Conclusion: Gelatinization and natural fermentation are therefore adaptable technologies, especially at rural levels, to improve acceptability and bulk reduction of resistant starch-based complementary foods.