THE CUBA REVIEW 



31 



from the cane, beet, etc., treated to remove the nonsaccharin sub.stances which prevent crystal- 

 lization, and evaporated in vacuum apparatus to prevent burning; the sugar is then crj'stal- 

 lized, and the crystals separated from the molasses in centrifugals. Modified methods of 

 manufacture may produce white granulated sugar direct from the beet or the cane. When 

 these are not used, the product is "raw sugar" which must be passed through some refining 

 process before it is white sugar. The methods of manufacturing sugar from the beet are 

 described in a previous bulletin of this series. (<') 



The average composition of raw sugar from a number of different sources is as follows: 



Average composition of raw sugar. 



Raw sugar from the.se various sources takes on in each case the chaiacter of the impuri- 

 ties from which it has not yet been freed. Thus, the raw products of the sugar cane, maize, 

 and the sugar maple, are pleasant in flavor, that of the beet is acrid and di.sagreeable, while 

 the raw palm sugar or jaggary is of low sweetening power, because of the large amount of 

 invert sugar (dextrose and levulose) that has resulted from fermentation and too high a de- 

 gree of heat used in evaporation. From all these raw sugars the pure cane sugar, or sucrose, 

 as known to the chemist, can be crystallized out, and in every ca.se the sugar is identical in 

 chemical compo.sition, appearance, and properties. By no chemical test can the pure crystal- 

 lized sugar from these different .sources be distinguished. There is a popular impression to 

 the contrary, however, and it is often as.serted that beet sugar has less sweetening power, 

 or that fruits preserved with it do not keep as well, but this can be true only of specimens 

 that have been imperfect Ij' purified. 



Tests made at the California E.xperiment Station (/) led to the conclusion that the two 

 sorts of sugar were equally valual)le for canning, and identical in their behavior when of the 

 same finene.ss of crystallization. 



Methods of refining raw sugar have been so improved in the last few years that it may 

 be truly said that few food substances are so nearly pure chemically as the best granulated 

 or lump sugar. 



PURITY OF SUGAR 



Of 500 samples of sugar examined several years ago by the Bureau of Chemistry of this 

 department,((/) not one was found to be adulterated. The low price of cane sugar, in comparir 

 son with the price of substances that might be used for adulteration, protects it from such 

 attempts. 



A more recent pubUcation of the Bureau of Chemistry {h) states that sugars as a class, 

 both the high and low grades as now found on the market, are practically free from adultera- 

 tion. This is particularly true since the Federal pure-food law of 1906 went into effect. 



There is a popular belief that granulated .sugar is often adulterated with white sand or 

 finely ground rock, and that pulverized sugar is commonly adulterated with starch or lime dust. 

 Cases of such adulteration, however, have rarely been found by the Bun^au of Chemistry, 

 though starch has been detected in a very few^ samples of powdered sugar. It is a very .simple 

 matter to test suspicious sugar for the presence of such materials. Sugar is readily soluble 

 in water, and the sand and mineral adulterants are insoluble. If a spoonful of sugar is added 

 to a gla.ss of water and stirred, it wuU completely dis.solve, while any sand or similar material 

 will remain undissolved. If the w^ater is warm the sugar will dissolve more quickly than 

 otherwise, and care must be taken to continue the stirring for considerable time, as some of 

 the very crystalline sugars dis.solve rather slowly. 



e U. S. Dept. Agr., Farmers' Bui. 52. / California Sta. Circ. 33. 

 pt. 0. h U. S. Dept. Agr., Bur. Chern. Bui. 100. 



a U. S. Dept. Agr., Div. Chem. Bui. 13, 



