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.

The Effect of Unsaponifiable Fraction from Palm Fatty Acid Distillate on Lipid Profile of Hypercholesterolaemia Rats

“…The bioactive compounds of USF are vitamin E of 0.80%, phytosterols of 9.16%, squalene of 1.14% [6]. The difference of PFAD as vitamin E containing material form other vitamin E sources is rich in tocotrienols [10,11]. Lewis (2001) indicated that tocotrienols have hypocholesterolaemic property and have the ability to reduce LDL cholesterol level [12].…”

Ionic Liquid-Mediated Liquid-Liquid Extraction

“…However, the separation of mixed tocopherol homologues has been very challenging because of their high structural similarity. The available methods for this problem mainly include various chromatographic technologies, such as high performance liquid chromatography (Ng et al, 2004;Pyka & Sliwoik, 2001), capillary electrochromatography (Chaisuwan et al, 2008), microemulsion electrokinetic chromatography (Chang et al, 2006), nano-liquid chromatography (Fanali et al, 2002), supercritical fluid chromatography (Jiang et al, 2003) and low pressure column chromatography (Wan et al, 2008). Although these technologies could give effective separation for the tocopherol homologues, they are almost only applied at a laboratory scale on account of the low throughput capacity and large consumption of absorbents and solvents or the requirement for special equipment.…”

Vitamin E and Beta Carotene Composition in Four Different Vegetable Oils

“…Tocopherols differ from tocotrienols in that there are three double bonds in the side chain of the tocotrienols. There is a possibility that vitamin E isomers with only one or two double bonds in the side chain are present in palm oil (Ng et al, 2004). Tocopherol and tocotrienol have different biological activities towards free radicals and may play significant role as signaling molecule in cellular activities (Sue-Mian et al, 2010).…”