Determination of saponins in legumes by direct densitometry.
Research has shown that dietary saponins may have health benefits. A simple, rapid method for the determination of saponins in legumes, using densitometry, is described. Saponin preparations, after pretreatment to remove nonsaponin components, are spotted in rows on a thin-layer chromatography plate, along with soyasaponin standards. The plate, without solvent development, is directly treated with sulfuric acid and heated. Violet spots develop which have a density proportional to the amount of saponin present. The standard curve has a correlation coefficient of 0.99 and is linear over the range of 1.25 to 10 microg of soyasaponins applied. The method has a coefficient of variation of less than 3% and compares favorably with quantitative thin-layer chromatography. Using this method the saponin contents of defatted soy flour (0.58%), dried navy beans (0.32%), and dried kidney beans (0.29%) were determined, and these results were found to be consistent with previous reports in the literature.
Gurfinkel
D M
DM
Department of Nutritional Sciences, University of Toronto, 150 College Street, Toronto, Ontario, Canada, M5S 3E2.
Rao
A V
AV
D002855:Chromatography, Thin Layer / Q000379:methods; D003720:Densitometry / Q000379:methods*; D007887:Fabaceae / Q000737:chemistry*; D012503:Saponins / Q000032:analysis* / Q000302:isolation & purification; D012680:Sensitivity and Specificity
D012503:Saponins