COMPARATIVE EVALUATION OF SENSORY ATTRIBUTES AND MICROBIAL SAFETY OF TIGER NUTS (CYPERUS ESCULENTUS L.) PROCESSED BY DIFFERENT DRYING METHODS

Abstract

This study investigates the sensory and microbial contents of fresh tiger nuts processed with three drying methods: sun drying, oven drying, and the Nigerian Stored Products Research Institute Parabolic Shaped Solar Dryer (NSPRI PSSD), while dried tiger nuts from the market serve as a control, to evaluate their sensory performance and effectiveness in minimizing microbial loads. Before sensory, thirty trained panelists evaluated five sensory attributes (appearance, aroma, taste, color, texture) using a 9-point hedonic scale. One-way ANOVA with Tukey’s post-hoc test at a 95% confidence level revealed significant differences (p < 0.05) among all samples. Microbial analysis through serial dilution using the pour plate method. NSPRI PSSD had the highest overall acceptability (8.67, CI:8.43–8.91), showing a 16% improvement over Sample C (7.45) and a 102% improvement over Sample D (4.30). NSPRI PSSD (8.65) and market dried (4.25, 3.50) revealed the widest variation in taste and aroma. Various drying techniques significantly lowered microbial loads, with NSPRI PSSD proving to be the most effective. Critical pathogens such as Escherichia coli and Salmonella spp. were identified and isolated. These results underline the importance of implementing controlled drying methods to improve the safety and sensory quality of dried tiger nuts, providing essential evidence-based guidelines for food processing and consumption.