Role of bacteria isolates in the spoilage of fermented African oil bean seed ugba

Abstract

Study was carried out to determine the spoilage association of traditionally fermented ugba, product of African oil bean seed. Samples were collected from three markets within Enugu metropolis in Eastern Nigeria. Microbial population of ugba was isolated, characterized and identified. Effect of time on product quality, total viable cell count and individual growth pattern of isolates was evaluated. Microorganisms isolated were Proteus sp., Klebsiella sp., Staphylococcus epidermidis, E. coli Bacillus licheniformis and Bacillus subtilis. Initial viable cell count increased from 4.6×l08-6.2×l08, 6.0×l09-6.9×l09 and 3.9×108-5×l08 cfu g-1 by the 4th day for samples from Mayor, Kenyatta and Garki markets, respectively. Organoleptic changes in texture and colour were seen to be a factor of time of storage. A decline ingrowth of Proteus sp., ii. coli, Klebsiella sp. and S. epidermidis by the 4th day of storage was observed for all samples. Viable cells ofS. licheniformis increased from 6.1 ×107-17.7×107cfu g-1,13.9×l08-20.0×l08 and 8.7×l07-15.5×l07 by the 4th day of storage for samples from Mayor, Kenyatta and Garki markets respectively. Growth of B. subtilis increased from 9.2×l07-19.9×l07, 14.9×l08-21.2×l08 and 11.5×l07-17.2×l07 cfu g-1 for samples from Mayor, Kenyatta and Garki markets respectively. Our results indicate that ugba spoilage is primarily a result of the continued activity of African oil bean seed fermentative organisms B. subtilis andS. licheniformis. © 2010 Asian Network for Scientific Information.