determination of tocopherols and tocotrienols in palm oils

Determination Of Tocopherols And Tocotrienols In Palm Oils.

Name : Ifianly Bin Karim 156496Supervisor : Dr. Mohd. Nazrim Marikar

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What is actually palm oil ?

• Palm oil is natural oil extracted from the fleshy orange-red mesocarp of the fruit from the oil palm (Elaeis guineensis).

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3Figure 1 – General flow of production of Palm Oil.

What is tocopherols and tocotrienols ?

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Both are known as tocols (vitamin E)

• Amphipathic and lipid-soluble compounds• a polar chromanol ring • hydrophobic 16-carbon side chain• Each consist of 4 isomers -α-, -β-, -ϒ-, -δ-• palm oil – only 5 (α-T) , (α-T₃) , (ϒ-T) , (ϒ-T₃) , (δ-T₃) T = tocopherol T₃ = tocotrienol

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Figure 2 - Chemical structures of tocopherols and tocotrienols.

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Importance of Tocols

• Chemical property – antioxidant activity• The ability to protect polyunsaturated lipids

from oxidation.• The palm’s tocol isomers are known for their

antioxidant properties which make them popular ingredients in pharmaceuticals, cosmetics formulations and health supplements.

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How to determine tocols ?

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Gas chromatography High performance liquid chromatography

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Tocols can be analysed by gas chromatography, both with flame-ionization and mass spectrometric detection, but the methods that are usually recommended involve high-performance liquid chromatography with fluorescence detection.

High performances liquid chromatography

• both normal-phase (NP) and reversed-phase (RP) chromatography.

• All eight tocols have been base-line separated by NP-HPLC using silica columns.

• Using 4–5 % (v/v) of 1,4-dioxane in hexane as the mobile phase with several silica columns, tocols were always eluted in the following order: α-tocopherol < α-tocotrienol < β-tocopherol < γ-

tocopherol < β-tocotrienol < γ-tocotrienol < δ-tocopherol < δ-tocotrieno

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Continued…

• RP-HPLC has the advantage over using NP-HPLC that less hazardous mobile phases e.g. methanol or ethanol.

• Saponification - removal of acyl lipids to avoid contamination of the RP column.

• By using a C30-bonded silica column and methanol as the mobile phase, it was possible to separate α-tocopherol and all tocotrienols in palm oil.

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Detection of tocols

• Tocols absorb UV light at λ=290-300 nm• Fluorescence detection (FLD)• Better sensitivity and higher selectivity of

HPLC analysis• Excitation wavelength of 290-296 nm and an

emission wavelength of 325-330 nm are commonly used

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Continued…

• Mass spectrometry (MS) has also been used to detect tocols.

• Negative ion APCI (atmospheric pressure chemical ionization) was found the best choice among negative and positive ion electrospray and APCI ionization modes to detect and quantify tocopherols.

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References

1. Kamal-Eldin, A. and Appelqvist, L. The chemistry and antioxidant properties of tocopherols and tocotrienols. Lipids, 31, 671-701 (1996).

2. Eitenmiller, R.R. and Lee, J. Vitamin E, Food Chemistry, Composition, and Analysis. Pages 540. Marcel Dekker Inc., New York, NY (2004).

3. Kamal-Eldin, A., Gorgen, S., Pettersson, J. and Lampi, A.M. Normal-phase high-performance liquid chromatography of tocopherols and tocotrienols - comparison of different chromatographic columns. J. Chromatogr. A, 881, 217-227 (2000).

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4. Bustamante-Rangel, M., Delgado- Zamarreno, M.M., Sanchez-Perez, A. and Carabias-Martinez, R.. Determination of tocopherols and tocotrienols in cereals by pressurized liquid extraction-liquid chromatography-mass spectrometry. Anal. Chim. Acta, 587, 216-221 (2007).

5. Ng, M.H., Choo, Y.M., Ma, A.N., Chuah, C.H. and Hashim, M.A. Separation of vitamin E (tocopherol, tocotrienol, and tocomonoenol) in palm oil. Lipids, 39, 1031-1035 (2004).

6. Abidi, S.L. Tocol-derived minor constituents in selected plant seed oils. J. Am. Oil Chem. Soc., 80, 327-333 (2003).

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Summary

• Palm oil ( Elaeis guineensis ) • Tocols consist of tocopherols and tocotrienols• Important of tocols as in the antioxidant

activity.• Highly recommended to determine tocols by

using high performance liquid chromatography and fluorescence detection.

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