NICOTIANA 



M anuf acture 



THE TOBACCO PLANT 



Changes 

 during 

 Manufac- 

 ture. 



Fermenta- 

 tion. 



Enzymic 

 Action. 



Oxidase. 



Peroxidase. 

 Catalase. 



Sugar. 



Spanish Cigar-filler Leaf," the " Florida Cigar-filler Cuban Seed." [Of. 

 Floyd, World's Exhib. Leaf Tobacco at Paris Expos. 1900, in U.S. Yearbook, 

 Agri. Dept., 1900, 157-66; McNess and Mathewson, Dark Fire-cured Tobacco 

 of Virginia, etc., U.S. Yearbook, Agri. Dept., 1905, 219-30.] Much depends, 

 apparently, on the care in handling and the skill in making up the bundles. 

 There would accordingly seem every prospect of limitless expansions of the 

 Indian tobacco trade, through the simple bestowal of greater care in the 

 manufacture and in the methods of bundling and handling the leaf. Al- 

 though the past century has witnessed a great advance there is still much 

 room for improvement. Any one who will take the trouble to inspect the 

 chief tobacco area of India will readily discover that the fault is not so 

 much the climate, soil and plant, as the defective methods of curing that 

 consign the Bengal tobacco to the humble position it- usually occupies in 

 the markets of the world. 



Changes occurring during Manufacture. Dr. Harold H. Mann, in a 

 communication with which I have been favoured, discusses the modern 

 opinions on this subject : " It has been repeatedly pointed out by writers 

 on this subject that dry Nicofiana Tabacum leaf is not tobacco. Dela- 

 croix (Bull. Scient. Pharm., Feb. 1905, No. 2) remarks, for example, that 

 the quantity of albuminoids present in the normal leaf gives a disagreeable 

 odour to the smoke that recalls that of burning wool or horn. The fer- 

 mentation which the leaf undergoes during manufacture is, in fact, essential 

 to the preparation of tobacco, and if not carried out properly, the finest 

 leaf may be rendered entirely worthless. Many theories have been held at 

 various times as to the nature and cause of the great changes which take 

 place, and it has been successively believed that they were due simply to 

 the oxidising action of the atmosphere at the high temperature which 

 was produced (100 to 120 F.), (Schloesing, Nessler) ; that definite mi- 

 crobes or bacteria were the necessary agents in producing the flavour of 

 tobacco (Suchsland, Koning, Vernhout), and even that each class of 

 tobacco had its own special bacterium ; and that such changes as occur 

 are principally, if not entirely, due to the presence and action of oxidising 

 enzymes or unorganised ferments (Loew). It is now almost universally 

 recognised that oxidising enzymes are the principal agents in producing 

 the development of the colour and aroma characteristic of prepared 

 tobacco leaf. 



" These enzymes, which were first isolated and examined by Oscar 

 Loew in America, appear to be at least three in number. The first of 

 these (oxidase) is an exceedingly active ferment, but very susceptible to 

 noxious influences, being destroyed by heating to the very moderate 

 temperature of 150 F. ; the second (peroxidase) is not nearly so active, 

 but is more resistant, and is only destroyed at 190 F. ; the third (catalase) 

 is of a different character, more resistant than either, but the part it takes 

 in the processes of manufacture is not yet understood. The processes of 

 curing (drying) and sweating (fermentation) of the tobacco leaf are ac- 

 companied by a destruction of these enzymes present in the leaves ; the 

 oxidase and peroxidase generally survive the curing process but the former 

 of these finally disappears in the sweating (fermentation), leaving the more 

 resistant peroxidase. 



'" The changes induced by these ferments are very considerable. During 

 the drying (curing) of the leaves, the starch is transformed, and the greater 

 part of the sugar which results disappears. The albuminoids decrease 



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