Interference of Plant Polysaccharides and Tannin in the Coomassie Blue G250 Test for Protein
Article first published online: 25 AUG 2006
Journal of Food Science
Volume 48, Issue 4, pages 1346–1347, July 1983
How to Cite
GODSHALL, M.A. (1983), Interference of Plant Polysaccharides and Tannin in the Coomassie Blue G250 Test for Protein. Journal of Food Science, 48: 1346–1347. doi: 10.1111/j.1365-2621.1983.tb09227.x
- Issue published online: 25 AUG 2006
- Article first published online: 25 AUG 2006
- Ms received 3/18/83; accepted 4/1/83.
Coomassie Blue G-250, a quantitative color reagent used for protein analysis, reacts with tannin and polysaccharides found in cane juice and raw cane sugar. For this reason, the dye could not be used as a reagent for protein in these products. However, spectroscopic data showed that the complex formed with phenolic compounds possessed a different maximum than the protein complex. The spectrum of the complex between the dye and the nondialyzable fraction from raw sugar indicated the presence of phenolic moieties attached to this high-molecular weight fraction. The reaction of several common plant polysaccharides and tannins with the dye could constitute a serious source of error in its use to determine protein in plant extracts.