A critical evaluation of the vanillin reaction as an assay for tannin in Sorghum grain
Price, M.L.
A critical evaluation of the vanillin reaction as an assay for tannin in Sorghum grain - Washington, DC (USA) : American Chemical Society, 1978.
Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0021-8561 Peer review
Several parameters of the vanillin assay were examined to determine which must be most closely controlled to ensure accuracy and reproducibility. A 20-min extraction in methanol was found to be adequate. When corrected for background color, the modified vanillin assay was found to give nearly identical values with those obtained with the regular vanillin assay, except with group I1 sorghum. The reactions of tannin and catechin, the usual standard, with vanillin were found to differ markedly in reaction kinetics. Assays of purified tannin showed that use of catechin equivalents overestimates tannin content. The assay was found to be extremely temperature dependent. Revised procedures for the vanillin assay are presented which give excellent reproducibility.
Text in English
0021-8561 1520-5118 (Online)
https://doi.org/10.1021/jf60219a031
Vanillin
Tannins
Sorghum
A critical evaluation of the vanillin reaction as an assay for tannin in Sorghum grain - Washington, DC (USA) : American Chemical Society, 1978.
Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0021-8561 Peer review
Several parameters of the vanillin assay were examined to determine which must be most closely controlled to ensure accuracy and reproducibility. A 20-min extraction in methanol was found to be adequate. When corrected for background color, the modified vanillin assay was found to give nearly identical values with those obtained with the regular vanillin assay, except with group I1 sorghum. The reactions of tannin and catechin, the usual standard, with vanillin were found to differ markedly in reaction kinetics. Assays of purified tannin showed that use of catechin equivalents overestimates tannin content. The assay was found to be extremely temperature dependent. Revised procedures for the vanillin assay are presented which give excellent reproducibility.
Text in English
0021-8561 1520-5118 (Online)
https://doi.org/10.1021/jf60219a031
Vanillin
Tannins
Sorghum