title: Separation of vitamin E (tocopherol, tocotrienol, and tocomonoenol) in palm oil.
abstract: Previous reports showed that vitamin E in palm oil consists of various isomers of tocopherols and tocotrienols [alpha-tocopherol (alpha-T), alpha-tocotrienol, gamma-tocopherol, gamma-tocotrienol, and delta-tocotrienol), and this is normally analyzed using silica column HPLC with fluorescence detection. In this study, an HPLC-fluorescence method using a C30 silica stationary phase was developed to separate and analyze the vitamin E isomers present in palm oil. In addition, an alpha-tocomonoenol (alpha-T1) isomer was quantified and characterized by MS and NMR. (alpha-T1 constitutes about 3-4% (40+/-5 ppm) of vitamin E in crude palm oil (CPO) and is found in the phytonutrient concentrate (350+/-10 ppm) from palm oil, whereas its concentration in palm fiber oil (PFO) is about 11% (430+/-6 ppm). The relative content of each individual vitamin E isomer before and after interesterification/transesterification of CPO to CPO methyl esters, followed by vacuum distillation of CPO methyl esters to yield the residue, remained the same except for alpha-T and gamma-T3. Whereas alpha-T constitutes about 36% of the total vitamin E in CPO, it is present at a level of 10% in the phytonutrient concentrate. On the other hand, the composition of gamma-T3 increases from 31% in CPO to 60% in the phytonutrient concentrate. Vitamin is present at 1160+/-43 ppm, and its concentrations in PFO and the phytonutrient concentrate are 4,040+/-41 and 13,780+/-65 ppm, respectively. The separation and quantification of alpha-T1 in palm oil will lead to more in-depth knowledge of the occurrence of vitamin E in palm oil.
authors.affiliation: Malaysian Palm Oil Board, Selangor, Malaysia.
authors.forename: Mei Han
authors.initials: MH
authors.lastname: Ng
authors.forename: Yuen May
authors.initials: YM
authors.lastname: Choo
authors.forename: Ah Ngan
authors.initials: AN
authors.lastname: Ma
authors.forename: Cheng Hock
authors.initials: CH
authors.lastname: Chuah
authors.forename: Mohd Ali
authors.initials: MA
authors.lastname: Hashim
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004951:Esterification; D000073878:Palm Oil; D010938:Plant Oils / Q000737:chemistry*; D024505:Tocopherols / Q000302:isolation & purification; D024508:Tocotrienols / Q000302:isolation & purification; D014810:Vitamin E / Q000302:isolation & purification*
chemical_list: D010938:Plant Oils; D024508:Tocotrienols; D014810:Vitamin E; D000073878:Palm Oil; D024505:Tocopherols