Ugwu Chidiebere Emmanuel^1,, Nduka C², Maduka Hugh Clifford Chima^{1, 2}, Okpogba Aloysius Ngozi¹, Ogueche Peter Nnamdi¹

Lipases are glycerol ester hydrolases which hydrolyze esther linkages of glycerides at water-oil interface. The activities of lipase in fermented oil bean seeds (ugba), fermented castor oil seeds (ogiri) and kunu were determined with respect to the levels of free fatty acids produced from each sample. The samples were prepared by local adoption of processing oil bean and castor seeds. The seeds were cooked (100°C) in cooking pot for 4hr, chopped into pieces, washed with clean tap water and covered in a stainless pot and allowed to ferment at room temperature. The lipid peroxidation and lipase activity were also determined on the fermented products using standard methods. The total free fatty acid determined were 349± 7, 1026± 5 and 94± 5mg/ml for ugba, ogiri and kunu respectively. The level of lipid hydroperoxide concentrations of fermented ugba, ogiri and kunu were (2.5 ±0.3) ×10^-4, (1.57 ±0.05) ×10^-4 and (4.5 ±0.3) × 10^-4 mg/ml malondialdehyde respectively. It was observed that the higher the peroxidation or concentration of malondialdehyde in a given sample, the least the lipase activity as determined by the level of free fatty acids. The findings of this research indicate that fermented ugba, ogiri and kunu could be good sources of lipase for industrial application.

lipase activity, malondialdehyde, free fatty acid, fermentation, lipid peroxidation