Characterization of Oil from Bran of Rice Varieties Grown in Ebonyi State

Abstract

The present work evaluated some physicochemical properties of oil extracted from the bran of three rice varieties: Nwangeilla, Adanaama, and CP, grown across Ebonyi State, southeast Nigeria. Oil was isolated from rice bran using solvent extraction, and analyzed for peroxide, saponification, iodine, and free fatty acid (FFA) values; smoke, flash, and fire points; oil yield; density; and fatty acid profile, using standard methods. Results revealed that CP rice bran oil recorded the highest FFA (2.83%) and peroxide (3.57 meq/kg) values. The highest oil yield (13.45%) was recorded for Adanaama oil while the highest smoke (257oC), flash (280oC) and fire (310oC) points were recorded for Nwangeilla oil. The smoke point, fire point, FFA and peroxide values of Nwangeilla oil were similar to those of Adanaama oil. Saponification and iodine values ranged from 185-188 mgKOH/g and 98-107g l2/100g respectively and were within Codex Standard for rice bran oil. In terms of fatty acid composition, Nwangeilla oil had the highest level of saturated fatty acids (27.37%) while CP and Adanaama had the highest and similar amounts of MUFA (42.52 and 42.31% respectively) and PUFA (33.17 and 33.31% respectively). In all three-rice bran oil studied, oleic acid was the predominant fatty acid, ranging from 39–41%; followed by linoleic acid (30–31%), and lastly by palmitic acid (21%). Linolenic acid (C18:3) was also identified in all samples and ranged from 1.23–2.08% with CP oil recording the highest C18:3 value, and Nwangeilla oil the lowest. Findings of this work point to the untapped opportunities within Nigeria’s rice bran oil sector.