Vanillin-HCl method for condensed tannins: Effect of organic solvents used for extraction of tannins
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Tannins are generally extracted using aqueous organic solvents, mainly methanol and acetone. The presence of various concentrations of methanol in the sample containing catechin or tannins did not alter the kinetics of their reaction, but the absorbance depended on the amount of methanol in the sample; the higher the methanol, the higher was the absorbance. Acetone reacted with acidified vanillin to produce a chromogen with λmax at 548 nm, which produce a substantial error in the determination of condensed tannins. In the presence of acetone, the time courses of the reaction for catechin and tannins were different, which depended on the acetone concentration and the reaction temperature. Reaction conditions for catechin and tannins that enable their measurement in the presence of acetone are presented.
- Broadhurst, R.B., andJones, W.T. 1978. Analysis of condensed tannins using acidified vanillin.J. Sci. Food Agric. 29:788–794.
- Deshpande, S.S., Cheryan, M., andSalunkhe, D.K. 1986. Tannin analysis of food products.CRC Crit. Rev. Food Sci. Nutr. 24:401–449.
- Cork, S.J., andKrockenberger, A.K. 1991. Methods and pitfalls of extracting condensed tannins and other phenolics from plants: Insight from investigations onEucalyptus leaves.J. Chem. Ecol. 17:123–134.
- Hagerman, A.E. 1988. Extraction of tannins from fresh and preserved leaves.J. Chem. Ecol. 14:453–461.
- Makkar, H.P.S., Singh, B., andNegi, S.S. 1990. Tannin levels and their degree of polymerisation and specific activity in some agroindustrial byproducts.Biol. Wastes 31:137–144.
- Makkar, H.P.S., Singh, B., andDawra, R.K. 1991. Tannin levels in the leaves of some oak species at different stages of maturity.J. Sci. Food Agric. 54:513–517.
- Price, M.L., Scoyoc, S.V., andButler, L.G. 1978. A critical evaluation of the vanillin reaction as an assay for tannin in sorghum grain.J. Agric. Food Chem. 26:1214–1218.
- Strumeyer, D.M., andMalin, M.J. 1975. Condensed tannins in grain sorghum: Isolation, fractionation, and characterization.J. Agric. Food Chem. 23:909–914.
- Vanillin-HCl method for condensed tannins: Effect of organic solvents used for extraction of tannins
Journal of Chemical Ecology
Volume 19, Issue 4 , pp 613-621
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- Kluwer Academic Publishers-Plenum Publishers
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- Condensed tannins
- vanillin-HCl method
- organic solvents
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