57$ MICROBIOLOGY OF FOODS 



of lactic organisms during the mashing process. In some factories, 

 the lactic fermentation is carried out in a special tank separate from 

 the general mash tank; this acidified liquid is then added to the sacchar- 

 ified liquid from the mash tank. This method greatly simplifies the 

 mashing of the malt used for the main bulk of the syrup, making pre- 

 liminary mashing at 50 to 52 unnecessary. 



"Malt glucose" or refined malt syrup is a colorless syrup resembling 

 ordinary refined corn syrup in appearance but is sweeter and of richer 

 flavor. It is usually prepared by saccharifying gelatinized corn or 

 rice starch with barley malt; followed by decolorizing the sugary 

 liquid with bone "coal" or vegetable decolorizing carbon and concen- 

 trating under a high vacuum. The use of starch with the barley malt 

 reduces the amount of protein in the syrup and renders the liquid more 

 easily decolorized than straight malt syrup. 



Malt syrup containing in concentrated form an extract of hops as 

 well as the maltose and other compounds from malt has been produced 

 for small scale beer-making purposes or for export for beer making. 

 It is made by mashing barley malt in the usual manner as for brewing, 

 followed by boiling with hops and concentration in vacuo to a heavy 

 syrup. 



Partially refined malt syrup diluted to about 70 Brix makes a 

 satisfactory table syrup. 



TOBACCO* 



The curing of tobacco results in the evolution of considerable heat 

 and rather profound changes in the composition, appearance, aroma, 

 and flavor of the product. It was thought at one time that most of the 

 changes were bacteriological but it now appears that enzymatic activi- 

 ties of the plant are also responsible for the transformations noted. 

 From 12 to 40 per cent, of the dry matter of the leaves is lost in the 

 various curing processes. The principal changes are the disappearance 

 of starch and reducing sugar; a decrease in pro terns, nicotine, pentosans, 

 and malic acid; and an increase in citric acid. Ammonia is formed. 

 After drying, the leaves are piled in masses, moistened, and allowed to 

 undergo a fermentation which raises the temperature to 50 to 55. 

 In some cases the leaves are sprinkled with a solution containing sugar, 



* Prepared by W. V. Cruess. 



