Microbiological and Sensory Evaluations of Fermented Rice Snack (masa) Supplemented with Soybean

The microbiological and chemical quality of rice masa with or without (control) 20% w/w soybean supplement were analyzed during production and ambient (28±2°C) storage. The aroma, visual appearance, firmness of the supplemented (SBS) and unsupplemented (USP) stored samples were also investigated. The Total Viable Counts (TVCs) of SBS decreased from 8.30 to 5.49 log10 cfu g-1 while that of USP increased from 5.38 to 8.93 log10 cfu g-1 during fermentation. Eleven microbial genera were identified during fermentation with Lactobacillus, Aspergillus and Saccharomyces spp predominating. Stored samples showed unacceptable sharp population increases after 24 h with maximum load occurring in the SBS. Significant difference (p = 0.05) existed in TVCs and pH of SBS and USP during production and storage. The aroma and visual appearance of SBS and USP differed significantly with aroma of SBS being more preferred. No significant difference existed in the firmness of both products.