Isolation, identification and characterization of predominant microorganisms in Swazi traditional fermented porridge (incwancwa) and optimization of fermentation conditions

Abstract

ABSTRACT The objective of the study was to isolate, identify and characterize the predominant microorganisms during the fermentation of incwancwa and optimize fermentation conditions. The lactic acid bacteria (LAB) load from fermented uncooked samples ranged from 4.6 ± 1.46 to 6.56 ± 0.2 log CFU/g whereas the load for yeast and coliforms ranged from 1.5 ± 0.39 to 2.12 ± 0.43 log CFU/g and 2.14 ± 0.22 to 4.09 ± 0.57 log CFU/g, respectively. LAB were the dominant microorganisms in incwancwa where Lueconostoc lactis was the main. Fermentation time and temperature had significant (p < .05) effect on the sensory perception of the product. The best temperature and time was found to be 32°C to 35°C for 8 to 24 hours. Numerical optimization predicted that the preferred temperature and time combination was 35°C for 15 hours. Thus, it is feasible to produce an acceptable incwancwa product under temperature/time conditions of 35°C for 15 hours using starter cultures derived from the original indegonuos flora of traditional incwancwa.