Microbiological And Organoleptic Changes Associated With Akpu Stored At Ambient Temparature

Abstract

Akpu was produced in the laboratory and used for the study. Spoilage was determined by changes in microbial population and diversity and organoleptic qualities of the food. Microbiological analysis revealed a progressive increase in the population of bacterial genera from 0 hr. (1.5 x 10² cfu/g) until 96 hr when the population began to stabilize (1.0 x 10⁶ cfu/g). The yeast reached its peak at 120 hr with a total population of 1.04 x 10⁴ cfu/g, while that of mould was 8.0 x 10³ cfu/g at the end of the study. Bacillus, Leuconostoc, Staphylococcus, Streptococcus, Klebsiella, Micrococcus, Flavobacterium, E. coli, Enterobacter, Saccharomyces, Aspergillus niger, Penicillium, Mucor and Rhizopus, were isolated. Succession was evident with 28.57%, 57.14%, 42.86%, 57.14% and 57.14% of the isolates obtained at 0 hr, 24 hr, 48 hr, 72 hr and 96 hr respectively, while 64.29% of the isolates were obtained at 120 hr. The pH equally decreased progressively but later decreased to 5.0 while the moisture content increased initially from 63.80% at 0 hr to 67.60% at 48 hr and decreased to 62.30% at 120 hr. Spoilage was observed after 48 hr. There was significant difference (p = 0.05) in the odour, slimminess, ropiness, texture, colour and taste between akpu at 0-48 hr and 72-120 hr. These results are important in the preparation of akpu especially as it is a popular food amongst Nigerians.

Global Journal of Pure and Applied Sciences Vol.11(2) 2005: 185-188