Quality characteristics and volatile compounds of oil extracted from njangsa seed

Abstract

AbstractUnconventional and underutilized plant oils are increasing popular and helping to meet demand for food, health and other industrial application. In recent years, the search for alternative sources that deliver healthful benefits, low‐environmental impact and ethical responsibility have become a priority to both scientists and industry. Oil from njangsa seed (Ricinodendron heudelotti) was recovered using four selected enzymes—hemicellulase, protease, pectinase, and amylase in an enzyme‐assisted aqueous extraction (EAE) and the recovery, quality indices and fatty acid composition was compared to solvent extraction using hexane (HE). Njangsa seed oil (NSO) recovered from the EAE ranged between 29 and 36% and were significantly (p < 0.05) lower than HE (46%), and the quality indices (free fatty acid, peroxide, para‐anisidine, and thiobarbituric acid values) were consistently lower and better than HE‐NSO. The fatty acid profile of EAE‐NSO was qualitatively and quantitatively comparable to HE‐NSO, with differences among the enzymes used. Alpha‐eleostearic acid was the most abundant fatty acid and was consistently ca 41% among the samples. Among the volatile compounds analyzed on the polar and nonpolar columns, 13 (2 alcohols, 9 aldehydes, and 2 esters) were detected in EAE‐NSO using hemicellulase, and 35 (4 aldehydes, 1 ester, and 30 hydrocarbons) in HE‐NSO. The most abundant flavor compounds identified were pentanal, methylcyclopentane, cyclohexane, 3‐methylpentane, (E,E)‐2,4‐nonadienal, (E)‐2‐heptenal, hexanal, 1‐butanol, and butanal. This study suggests that the amount, quality, and content of oil and volatile compounds in NSO can be influenced by the choice of extractant.