Prevention of Oxidation in Palm Oil Using Plants Extract

Abstract

Palm oil is one of the major edible oils widely consumed in Nigeria. Palm oil sold in the markets has been known to be high in free fatty acid which indicates oxidation and many synthetic chemical used to combat oxidation; though effective have been considered not safe. The effect of extracts from ginger rhizome and basil leaves on the lipid oxidation was studied. Ethanolic extract (70%) of ginger and aqueous extract of basil leave were added to fresh palm oil at concentration 100ppm, 200ppm and 300pppm and were stored under room temperature for 60 days. The antioxidant activities of the extract, the effect of the extracts on the peroxide value, free fatty acid value and the antioxidant effectiveness of the extracts were evaluated at interval 14 days using standard methods. The DPPH  radical scavenging activity, ferric ion reducing power, and total phenolic content  of the ginger and basil extracts  were 76% and 58.4%; 13.3 and 86 in100mg/g; 133 and 48 in 100mg/g respectively. The sample treated with 300ppm of ginger extract was the lowest in peroxide values of 14.5meq/kg compared with the untreated sample with 25meq/kg. It also showed the highest antioxidant effectiveness at the 60^th day of storage. Sample treated with 200ppm of basil extract shows the least of free fatty acid value of 8.58% at the end of 60^th day as compared to the untreated sample with 11.47%. There are significant differences (p ˂ 0.05) in the peroxide value, free fatty values, antioxidant effectiveness of the untreated and treated palm oil. It was concluded that ginger and basil extract reduced lipid oxidation in palm oil.

Keywords: Palm oil, Storage duration, Natural additives, Antioxidant