Fermentation induced changes in volatile components of African oil bean ( Pentaclethra macrophylla Benth ) seeds

摘要

Abstract Fermented African oil bean ( Pentaclethra macrophylla Benth ) seed also referred to as ?￠????Ugba?￠???? is a known delicacy, mainly consumed by Africans. Human migration has also led to the introduction of this delicacy into most European and American countries. This study shows the changes in volatile components of African oil bean ( P. macrophylla Benth ) seed at different stages of fermentation. A quantity of 0.3 kg each of dehulled and sliced raw sample and cooked unfermented sample were separately ground, while 2 and 4 days fermented samples obtained by inoculating 0.6 kg of cooked, sliced and washed sample with 0.5 g of 4 days fermented seed was divided into two of 0.3 kg each and ground at the second and fourth day of fermentation. GC-MS analyses of the volatile components showed 9,12-Octadecadienoic acid (Z,Z)- and its esters as highest in raw seed, with total percentage concentration of 96.301, while 9-Octadecenoic acid, methyl ester, (E)- was highest in cooked unfermented seed, with percentage concentration 55.204. Phenol, 2-methoxy-3-(2-propenyl)- and its esters were the highest observed in cooked 2 days fermented seed, with total percentage concentration of 50.596, while 9-Octadecenoic acid (Z)-, methyl ester was highest in cooked 4 days fermented seed with percentage concentration of 67.788. Aside from softening the delicacy, a 4 days chance fermentation of cooked P. macrophylla Benth seed also reduces the eight component lipids present in the cooked unfermented seed to a more nutriceutical three component lipids (Hexadecanoic acid methyl ester, 9-Octadecenoic acid (Z)-methyl ester and Methyl stearate).