摘要
Palm fatty acid distillate （PFAD）, a by-product of deodorization in palm oil refining, contains about 0.7%-1% vitamin E. The advantage of PFAD over other vitamin E sources is higher amount of tocotrienols than that of tocopherols. Vitamin E purification of unsaponiable matter of PFAD was aimed to remove other impurities to obtain high vitamin E concentration, mainly tocotrienols. This research used low temperature solvent crystallization to purify vitamin E. To optimize response of vitamin concentration, a response surface method was applied with three factors, i.e., the ratio between solvent and unsaponifiable matter （A）, crystallization temperature （B）, and crystallization time （C）. The relation of three factors was quadratic with equation Y = -128.54361 ＋ 41.33904A - 0.87995B ＋ 1.58941C ＋ 0.00290AB - 0.044324AC ＋ 0.00120BC - 3.33113A2 - 0.039535B2 - 0.02710C2. The optimum crystallization condition was obtained at ratio of solventto unsaponifiable matter of 6.04：1, crystallization temperature of-10.54 ℃, and crystallization time of 24.16 hours. Vitamin E enriched fraction from optimum crystallization conditions contained vitamin E of 20.13% （w/w）.
