Abstract: In this study, ogiri, a Nigerian fermented food condiment was prepared from castor oil bean using Bacillus subtilis as a monoculture starter for the production of three different fermented castor oil bean condiment samples: B1 (0% NaCl/Lime), B2 (2% NaCl), B3 (3% Lime). Variations in the composition of the castor oil bean with fermentation >96 h period were evaluated for organic acids and amino acids using high performance liquid chromatography. Organic acids were detected in the fermented castor oil bean samples as fermentation period increased to 96 h. At 96 h fermentation higher values were recorded in most of the samples. Organic acids identified were oxalic, citric, tartaric, malic, succinic, lactic, formic, acetic, propionic and butyric acids. The production of these organic acids are undoubtedly the determining factor in which the shelf-life and safety of the final production depends while the inhibition of pathogenic and spoilage flora is also dependent on a rapid and adequate formation of these organic acids. The three fermented castor oil bean samples also contained sufficient amount of amino acids. Sample B1 had the highest values in isoleucine, glycine and histidine while sample B2 had the highest value in leucine content with 0.915 μg mL-1 at 96 h fermentation, closely followed by sample B3 and B1 with 0.798 and 0.205 μg mL-1, respectively. The results of amino acid analysis indicated a high concentration of all amino acids at 96 h of fermentation which contributes to the flavour and aroma of the ogiri condiment.
M.C. Ojinnaka and P.C. Ojimelukwe, 2012. Effect of Fermentation Period on the Organic Acid and Amino Acid Contents of Ogiri from Ricinus communis. Journal of Food Technology, 10: 140-150.