MICROBIOLOGICAL PROFILE OF<i>MURCHA</i>STARTERS AND PHYSICO-CHEMICAL CHARACTERISTICS OF<i>POKO</i>, A RICE BASED TRADITIONAL FERMENTED FOOD PRODUCT OF NEPAL

Abstract

ABSTRACT Poko is a traditional rice based fermented food of Nepal prepared using murcha as the starter. The microbiological evaluation of eleven murcha starters showed that the lactic acid bacteria and yeast were dominant at 5×105 to 1.0×109 cfu g−1 range while fungi were present at 2×105 to 1.0×107 cfu g−1. Coliforms (1×102 to 1.4×105 cfu g−1), E. coli (1×103 cfu g−1), and. S. aureus (1×102 g−1) were present in some of the murcha starters. Bacillus cereus was absent in all the starters. The microbial succession during poko fermentation suggested that it was primarily a mixed fermentation of yeasts, molds and lactic acid bacteria. The quality poko product obtained after two days and three days of fermentation at 30°C had a pH, acidity, reducing sugar, total sugar, and alcohol in the range of 3.2–3.0, 1.1–1.3 (% LA), 14.4–15.6 (%), 14.6–18.2 (%) and 1–1.6 (%) respectively. These critical ranges of biochemicals in the poko, due to the fermentation process imparted desirable organoleptic characteristics to the product. Saccharomyces cerevisiae, Candida versatilis, Lactobacillus spp, Pediococcus spp and Rhizopus spp were the dominant microorganisms identified from the poko fermentation. The results suggest that the quality of poko depends upon the microbial flora of the traditional murcha starters.