Glucose does not crystallize, as does cane-sugar (sucrose), A chemical process was devised by Dr. Arno Behr for the crystallization of glucose, but it is regarded as impracticable by reason of being too expensive. Dr. Behr added to the liquid glucose a very small quantity of crystallized anhydrous dextrose. The mixture is filled into molds, and in 72 hours will be a solid mass of crystals of commercial dextrose. The blocks are next placed in a centrifugal machine to throw out the still liquid syrup, and the anhydrous dextrose remains as a crystalline mass.
Varieties of Because glucose does not crystallize it is used extensively in the pre serving industry. • Fruit put up in a syrup wholly or partially made of glucose has a more plump and natural appearance. than if pteserved in sugar. Comb-honey, when put into glass jars, is surrounded by strained honey to which has been added a proportion of glucose which pre vents its candying, and therefore the honey always remains pleasing to the eye. It is very largely used for mixing with cane-sugar mo lasses; as a substitute for extract of malt in brewing; and very freely in the manufacture of candy. It is said to have two-thirds the sweetening power of cane-sugar. The extent to which glucose is used in the making of jams, jellies, marmalades, preserves and canned fruit, together with tables showing the composition of commercial glucose and the composition of the ash of glucose, are given in Bulletin No. 66, Bureau of Chemistry, United States Depart ment of Agriculture; also with extensive tables showing the composition of the jams and other preserves in comparison with such as con tained no glucose. As a food it is very largely consumed as table syrups which are 85 per cent glucose and 15 per cent sugar-house syrup. These syrups are well liked and much purer than molasses. Glucose is also used as a filler for cheap soap, and in leather and tanning extracts.
Some candies are nearly all glucose, partic ularly such as are sold at the lowest prices. In the high-grade confections the finest grade is used, not as a substitute for sugar, but in the place of acids to prevent the cane-sugar from graining, for which purpose only a small is used. In the brewing of ale and beer it is claimed that a lighter liquor results when a proportion of glucose is added to the malt and that it is more palatable. It is as sumed that commercial glucose is the same as the glucose which comes from the action of diastase in changing the starch in malt into maltose sugar. As glucose is flavorless, all of the malt cannot be dispensed with. It is claimed that 100 pounds of glucose or grape sugar is equal to 123 pounds of barley-malt, and is much cheaper.
The Wholesomeness of Glucose.— This is really the most important question connected i with glucose, and one that is still unsettled. It
is a problem for the -physiologist rather than the chemist. Owing to many improvements made in the last 30 years, the conclusion ren dered by the government's experts in 1884 could be made much more emphatic in 1916. It was as follows: "The starch-sugar thus made and sent into commerce is of exceptional purity and uniformity of composition, and contains no in jurious substance. Though at best having only about two-thirds the sweetening power of sugar, yet starch-sugar is in no way inferior to cane-sugar in healthfulness, there being no evi dence before the committee that maize starch sugar, either in its normal condition or fermented, has any deleterious effect upon the system, even when taken in large quantities.° Dr. H. W. Wiley, formerly chief chemist of the United States Department of Agriculture, testified before a committee of the United States Senate as follows: °I have had occasion to make careful examinations of almost every variety of food that has ever been exposed upon our markets for sale. In •my opinion glucose is not deleterious to health. It, is wholesome, somewhat sweet, readily 'digested. I have al ways found, from the time I first began to in vestigate food products, that the series of foods known as glucose or grape-sugar, when properly made, are valuable food material and not in jurious." It is conceded by all thatglucose is as readily digested as maltose, which is esteemed as a food for convalescents. It is sufficient to add here that the industry adds materially to the revenue of the corn-producer, is a great boon to the farmer. The total production of glucose and syrups alone was valued at $18,541, 429 in 1914 and at $17,922,514 in 1909, the in crease being 3.5 per cent. The total quantity of glucose manufactured during 1914, including that consumed in establishments where pro duced, was 847,180,968 pounds. The output of grape-sugar increased from 159,060,478 pounds, with a value of $3,620,816, in 1909 to 174,368, 818 pounds, valued at $3,765,515 in 1914, or 9,6 per cent in quantity and 4 per cent in value. • Bibliography.— Armstrong, F. F., < The Simple Carbohydrates and the Glucosides' (London 1910) ; Dubrunfaut, (Sucrage des Vendages avec les Sucres raffines de Canne de Betterave); Frankel, J., (Practical Treatise on the Manufacture of Starch, Glucose, Starch sugar and. Dextrine) (Philadelphia. 1881); Na tional Academy of Sciences, on Glu cose,' prepared in response to a request made by the Commissioner of Internal Revenue, with bibliography of starch-sugar arranged chrono logically, 1790-1883 (Washington 14); (Glu cose in Confectionery,' a statement from the National Confectioners' Association of the United States (Philadelphia 1898).