The Chemical Changes That Occur During the Curing of Tobacco Leaves

Publisher Website
Google Scholar
Abstract
Five 50-kgm. lots of leaves (8th-11th leaf) were picked from plants of Connecticut shade grown tobacco on the same day. One lot was immediately extracted with boiling water; the other 4 were cured in the customary manner. Lots were removed at the expiration of 12 days (yellow stage), 18 days (brown stage), and 51 days (fully cured). From each lot a representative sample was dried and the remainder was exhaustively extracted with boiling water. The extracts, press cake, and dry leaf samples were analysed for total solids, ash, crude fiber, soluble carbohydrates, ether extractives, and total, ammonia, amide, amino, and nitrate N. After completion of the curing process, 96.4% of the water originally present in the fresh leaf had evaporated, and 19.8% of the organic solids of the leaf disappeared; about 1/2 of this loss had its origin in protein. During the same period 39% of the ether soluble extractives, 81% of the soluble carbohydrates, and 38 gm. of N, of which only 4 gm. could be accounted for as nicotine N, disappeared. Far reaching chemical changes set in very shortly after leaves are detached, since 3/4 of the loss of water and of soluble carbohydrates, and more than 1/2 of the loss of organic solids and of ether soluble constituents, occurred during the first 12 days. During this same period at least 1/2 of the potential amino N of the protein that underwent enzymatic hydrolysis was converted into amino and amide N, indicating that the essential sequence of reactions was protein N[forward arrow]amino N[forward arrow]ammonia N[forward arrow]amide N.

This publication has 6 references indexed in Scilit: