Preliminary studies on the microbiological and physico-chemical characteristics of fermented pounded yam.

摘要

Purpose: The aim of the paper is to evaluate the microbiological and physicochemical characteristics of fermented pounded yam, a unique and popular food of the Igbominas of Nigeria. Design/methodology/approach: Fresh pounded yam was prepared in the laboratory by a modification of the traditional method, and then fermented for varying periods of time (0-96 hours), also essentially by the traditional method. Analysis was carried out on the products following documented and established procedures. Findings: Data obtained indicated noticeable increases in the populations of all the groups of microorganisms investigated with increases in fermentation time, except coliforms which declined in population after 24 hours. Heating of the samples after each fermentation interval resulted in significant reductions in microbial populations such that coliforms could not even be detected after 24 hours of fermentation. Lactic acid production, an indication of flavour development, and pH drop were highest at 48 hours of fermentation. The samples also became softer with increases in fermentation period. The heated samples were considered safe microbiologically, since they contained neither coliforms nor faecal coliforms. Research limitations/implications: The consumption of fermented pounded yam is encouraged since it is safe microbiologically and develops a desired flavour, while further research should be carried out on the nutritional benefits. Practical implications: The findings here suggested that adequate heating after fermentation is necessary to eliminate any potential microbial contamination, and for full flavour development. Originality/value: The results of this research contribute to the knowledge of fermented foods, especially those that are indigenous to Nigeria and West Africa..