The refining and the oxidative stability of jatropha oil

Refined jatropha oil was obtained by alkali refining,bleaching,and deodorization of crude jatropha oil,the effect of refining process on the physicochemical property and fatty acid composition of oil,the oxidative stability of refined jatropha oil were studied by method of calefaction and acceleration with oven,and the shelf life of the refined jatropha oil was estimated. Results demonstrated that color of refined jatropha oil was reduced from(11.00±0.00)to(4.00±0.00),water and volatile matter contents was decreased from(7.50%±0.26%)to(0.50%±0.19%),acid value was decreased from(6.62±0.02) mg KOH·g^-1 to(0.26±0.01) mg KOH·g^-1,iodine value,saponification value,and average molecular weight had no significant changes which was(104.37±0.24) g·100 g^-1,(191.78±0.16) mg KOH·g^-1,and(877.57±2.43) g·mol^-1 g·mol^-1 respectively for refined jatropha oil. Fatty acid composition had no significant changes which was composed mainly of palmitic acid(13.36%±0.15%),stearic acid(4.25%±0.03%),oleic acid(32.61%±0.10%),and linoleic acid(43.36%±0.26%),and the unsaturated fatty acids content was up to(75.97%±0.36%). The results of oxidation stability demonstrated that the higher storage temperature of refined jatropha oil the higher POV,and the addition of antioxidant such as tertiary butylhydroquinone(TBHQ),butylated hydroxyanisole(BHA)and Vitamin E(V_E)was decreased the POV,and the most longest shelf-life of 208 d could be extended by adding 0.02% TBHQ as antioxidant with storage temperature was 20 ℃.