EFFECT OF LYE PRETREATMENT ON PROXIMATE COMPOSITION OF BENTONITE BLEACHED OIL

Abstract

Poor oil quality is a major problem in the food industries, responsible for product shelf life due to oxidative rancidity. This study explores the use of bentonite bleaching earth to improve palm oil quality after 0.1 N lye pretreatment. Palm oil was purchased from a local market in Sokoto metropolis. Exactly 100 g of oil was subjected to 0.1 N lye pretreatment and the percentage oil recovery was calculated. Afterwards, 5% and 10% bentonite clay were used to bleach the recovered oil at 80–90 °C for 15 minutes with constant stirring. The cooled oil was then filtered and proximate composition determined. The results revealed that 75% oil recovery in the 5% bentonite treated oil. The acid and peroxide value dropped significantly in the bleached oil when compared with the raw oil. The saponification value suggest an increased concentration of short chain fatty acids in the bleached oil. In conclusion, combination of lye pretreatment followed by 5% bentonite bleaching efficiently improved the quality attributes of red palm oil and attained 75% oil recovery.