METHOD FOR THE EVALUATION OF THE AROMA OF TOBACCO SMOKE AND CLASSIFICATION BY AROMA OF TYPES AND VARIETIES OF TOBACCOS

摘要

The method is used for objective numerical evaluation of the aroma of tobacco smoke of Oriental tobaccos and offers a chance for the classification by aroma of the types and varieties of Oriental and Virginia type tobaccos. A sample of dry, ground tobacco is subjected to analysis for the content of isovalerianic acid and the neutral fraction of essential oil by means of capillary gas chromatography, after which the aroma (A) is determined according to the formula A = 0.0946 x [Kisoval.] + 15.547, and the pleasure of aroma (A') by formula A' = 0.0156 x [Kisoval.] + 5.7448 wherein [Kisoval.] means the isovalerianic acid concentration in the sample, expressed in microg.g -1. The numerical values produced are related to reference scales expressing the aroma, as follows: highly aromatic tobacco smoke - mark over 20, medium aromatic tobacco smoke - mark 20, low aromatic tobacco smoke - mark under 20; and for the pleasure of the aroma, as follows: highest pleasure of the tobacco smoke aroma - mark 10; the lowest tobacco smoke aroma - marks 1 to 5, and intermediate pleasure of the tobacco smoke aroma - marks between 5 and 7. The aroma classification is made by processing of the chromatographic profiles of the chromatographic analysis of the neutral fraction of the essential oil based on the time of retention of each peak (tR) and the percentage participation of the height (H) of each peak from the sum of heights of the selected peaks in the processing of all chromatogrammes. The results are expressed by indexes of similarity (Is, %) between the compared samples. The classification is made on the aroma of tobacco smoke selected for reference value, the Is of which is taken for 100%, or by the comparison of the different tobaccos amongst them.