Nutrient changes during the fermentation of African oil bean (Pentaclethra macrophylla Benth) seeds

Abstract: The prepared seedslices of African oil bean (Pentaclethra macrophylla Benth) were subjected to a 72-hour traditional fermentation to produce ‘ugba ’ a popular food condiment consumed in the rain forest areas of West tropical Africa. The fermentation brought about slight increases in crude protein and ash contents, and a slight decrease in the oil content of the seeds. Amino nitrogen increased steadily from 1.23 mgNg DM prior to fermentation to 13.68 mg Ng DM after 72-hours, showing a strong indication of-1 -1 appreciable protein hydrolysis. Gas chromatographic analysis of the seed oil showed the principal fatty acid, linoleic acid, increasing from 60.68 to 67.57 % of total fatty acids while oleic acid decreased from 26.95 to 22.59%. Palmitic acid and other saturated fatty acids in the seed oil were also slightly affected by the fermentation; while palmitic increased steadily, others decreased markedly. Total titratable acidity increased gradually as fermentation progressed. A further analysis using thin-layer chromatography revealed the accumulation of formic, acetic, lactic and butyric acids in the fermenting seedslices. At the end of 72 hours, ‘ugba ’ contained 0.41 mgg butyric acid, 0.35mgg lactic acid, 0.18 mgg acetic acid and 0.20 mgg formic-1 -1 -1 -1 acid, on dry weight basis. Key words: Oil bean seeds, fermentation, chemical composition, fatty and organic acid