A semi-micro gravimetric method for the determination of 3-β sterols in free and combined forms is described. Preliminary methodological studies are also summarized. A number of green, aged or fermented samples of tobacco leaves and midribs was analyzed with the developed procedure. The approximate total sterol levels of all samples varied between 0.1 and 0.5 per cent. Aged samples of flue-cured, burley and Maryland leaves showed the highest sterol concentrations. These three types gave approximately similar levels. Turkish, fire-cured and cigar types contained progressively less total sterols. The midribs of commercial samples of aged or fermented tobaccos showed significantly less sterols than the leaf tissue. Although an accurate comparison between the sterol levels of green and aged leaves was difficult to make, it appears that curing and aging do not drastically alter the sterol contents of green leaves. All samples contained free, esterified and glycosidated sterols but no rigid correlation between the proportions of each and tobacco type was observed.

(Full article published with kind permission from "Tobacco International")