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Selective separation of tocol isomers by liquid−liquid extraction using choline−based deep eutectic solvents
  • Nu'man Abdul Hadi,
  • Mei Han Ng
Nu'man Abdul Hadi
Malaysian Palm Oil Board
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Mei Han Ng
Malaysian Palm Oil Board
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Abstract

In this paper we examined the potential for choline-based deep eutectic solvents (DESs) for selective extraction of tocol isomers from crude palm oil (CPO) through liquid-liquid extraction. The effect of increasing DES amount on the distribution and selectivity of tocol isomers (α-tocopherol, α-β, γ-, and δ- tocotrienol) were investigated. It was found that tocol isomers are distributed in the order of the hydrophilic power of the tocols, with more tocols of higher polarity distributed more into the stripping phase compared to the less polar tocols. Distribution coefficients for α-tocopherol, α-β, γ-, and δ- tocotrienol were 7.8, 13.1, 19.8, 22.1 and 29.6, respectively, when equal weight of CPO and choline chloride-malonic acid eutectic mixture (DES1) was used. With increasing DES1, the distribution of each tocol isomers also increased, due to the increasing polarity of the stripping phase that attracted more tocols. Selectivity of δ- tocotrienol which is the most polar, were always higher than other isomers (α-tocopherol: 3.81, α-tocotrienol: 2.22, β-tocotrienol: 1.50, γ-tocotrienol: 1.34). This confirmed the role of hydrophilic power of the tocols in selective separation of tocol isomers using DES in this study