Microbiological, Nutritional and Organoleptic Changes Associated with Fermented Oil Bean (Pentaclethra macrophylla Benth) Seed (ugba) Stored at Ambient Temperature

Ugba is the Igbo name of the fermented African Oil bean seeds (Pentaclethra macrophylla Benth). It is a traditional food condiment generally produced by natural fermentation and is an important and cheap source of protein for people whose staple foods are deficient in protein. The study was carried out to determine the microbiological, nutritional and organoleptic changes associate with ugba when stored at ambient temperature. The oil bean seeds were processed traditionally and subjected to a four day spontaneous fermentation to produce the ugba. One gram of the fermenting and fermented samples was serially diluted and 0.1 ml aliquots was plated by spreading on appropriate media for the isolation of bacteria and fungi. The isolates were purified and then characterized. The ugba sample was then stored in an air-tight container for 7 days. Each day, the sample was examined for sensory properties and acceptability by a team of panelists. The bacterial isolates recovered during the fermentation were Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Bacillus and Lactobacillus species while Aspergillus niger, Saccharomyces cerevisiae, Rhizopus species, Candida and Fusarium spp were the fungal isolates recovered from the sample. Only Bacillus spp and Lactobacillus spp were isolated at the end of the fermentation while Saccharomyces cerevisiae was the only fungus isolated at the end of the fermentation. The food borne pathogens and spoilage organisms were eliminated from the final product making the ugba safe for consumption. The ugba was found to be high in protein (27.64 %) and fat (24.93 %) but low in ash, fibre and carbohydrate. Acceptability of ugba was best on the 2nd and 3rd days of storage with acceptability scores of 79.22 and 78.9% respectively. Beyond the 4th day of storage, the ugba was not found acceptable for consumption. In conclusion, the production of ugba is by a mixed microbial flora. However, only health organisms GRAS (Generally Regarded As Safe) (Bacillus and Lactobacillus species) remained at the end of the fermentation as the contaminating food borne pathogens and spoilage organisms were eliminated from the final product making the ugba safe for human consumption. Fermentation also increased the protein and fat contents of the ugba thereby making it a good supplement for animal protein especially in rural areas where animal protein is very expensive to provide.