EFFECTS OF STEEPING PERIODS ON THE QUALITY OF SWEET POTATO FLOUR (IMPOMOEA BATATAS L.) IN YOLA ADAMAWA STATE

This study evaluated the effects of different steeping durations (8, 16, and 24 hours) on the quality of sweet potato (Ipomoea batatas L.) flour produced under controlled processing conditions. Fresh tubers were washed, peeled, sliced, steeped at specified times, oven-dried, milled, and analysed for proximate composition, microbial load, and sensory attributes. The experiment followed a Completely Randomized Design (CRD) with triplicate samples, and the data were subjected to one-way ANOVA at a 5% significance level. Results showed that microbial loads across all treatments were low and within safe consumption limits, with total coliform counts remaining below 1.2 log₁₀ CFU/g. Although yeast count was highest at 16 hours of steeping, the differences among treatments were not statistically significant. Steeping period significantly affected certain proximate parameters: crude fibre increased markedly with longer steeping (P = 0.007), while dry matter significantly decreased at 24 hours (P = 0.008). Crude protein, lipid, and ash contents were not significantly influenced by steeping duration. However, carbohydrate content (NFE) showed a sharp numerical decline at 24 hours, indicating substantial leaching and fermentation losses. Sensory evaluation revealed that porridge prepared from flour steeped for 16 hours was the most acceptable in colour, aroma, taste, texture, and overall acceptability, while the 24-hour treatment received the lowest scores due to over-fermentation characteristics. In conclusion, a steeping duration of 16 hours provided the best balance of microbial safety, nutrient retention, enhanced fibre content, and superior sensory quality. Steeping beyond 16 hours offered no nutritional or sensory advantage and contributed to undesirable carbohydrate loss and higher moisture retention. The findings provide practical, location-specific guidance for small- and medium-scale sweet potato flour processors seeking optimal processing techniques for improved product quality.