THE MANUFACTURE OF OTHER FERMENTED PRODUCTS SS7 



ing to Suchsland they are due to bacterial activities and by the use 6i 

 pure cultures he claims to have much improved ordinary tobacco. 



According to Nessler and Schlossing, the bacteria are useful only in 

 raising the temperature of the mass which is thus made more subject 

 to the action of atmospheric oxygen. This is the immediate cause of 

 the chemical changes. 



The third theory is that of Loew who ascribes the changes to the 

 action of enzymes, oxidases, peroxidases and catalases existing in the 

 leaves of the tobacco. 



It seems probable, according to many investigators, that the changes 

 are due in the first place to hydrolyzing, proteolytic and oxidizing 

 enzymes, and that these diastatic transformations are supplemented 

 by the bacteria which destroy nitrates and produce ammonia; variations 

 in these various factors account for variations in the characteristics of 

 tobacco. 



Prepaiiation and Conservation of Miscellaneous Products 



Indigo. — ^This dye was formerly made only from certain species of 

 Indigofera, principally /. tinctoria. This plant contains a glucoside, 

 indican, which by fermentation and oxidation yields indigo. 



The plants are placed in water at a temperature of 25° to 35° and 

 undergo a spontaneous alkaline fermentation which splits up the indican 

 into a sugar (indiglucin) and indigo white which remain in the solution. 

 This solution is then thoroughly aerated and the indigo white oxidized 

 into indigo blue which is insoluble and forms a sediment. This sedi- 

 ment is dried and constitutes the old indigo of commerce. 



Many bacteria are found in the fermenting liquid, but the cause of 

 transformation has been shown to be a specific form. Bacillus indigo- 

 genus, closely related to Friedlander's pneumonia bacillus. It is 

 strongly aerobic and surrounded by a gelatinous envelope. 



Retting. — ^The separation of the fibers of flax, hemp, ramie and 

 similar plants is brought about by a complex spontaneous fermentation. 

 The plants are either left on the surface of grassy meadows exposed to 

 alternate wetting and drjdng or immersed in water. In either case, 

 the tissues are gradually disintegrated by microbial action, more rapidly 

 in the wet process. 



The fermentation, principally bacterial, is due to many species. 

 Several have been described as being the principal agent in the process 



