32 FRUITS AND FRUIT PRODUCTS 



widely. Man}" samples of the better classes of goods contained not 

 more than from 10 to 15 per cent, while some of the cheapest jellies 

 were made up almost entirely of glucose, and many of the jams and 

 marmalades had only small proportions of fruit and apparently no cane 

 sugar. While glucose may be considered as an article of food, and as 

 such has no deleterious properties, its use in substitution for a more 

 expensive sugar must be considered a fraud unless its presence is indi- 

 cated in some way to the purchaser. If low-priced goods are pur- 

 chased it is not expected that the}^ will be made up of first-class materials, 

 and the use of glucose is the most efficient means of producing a cheap 

 article. At the same time all goods should be of the quality repre- 

 sented on the label. Many of the high-priced fruit products bought 

 upon the market were found to contain glucose. While the amount 

 of glucose used in the better grade of goods was usually small, there 

 was nothing upon the label to indicate that any glucose had been used 

 in their preparation. 



Considering the importance of glucose in the interpretation of the 

 results given in this bulletin, a brief account of methods of manu- 

 facture practiced in the United States is given. According to Saare*" 

 the raw product is always cornstarch. In the process of manufacture 

 of sirups hydrochloric acid is used almost entirely as an inverting 

 agent, but with sugars sulphuric acid may be used instead. The starch 

 is mixed to a milk of about 22^ to 23° Baume and 0.75 part of concen- 

 trated hydrochloric acid per 100 parts of dry starch added. The mix- 

 ture is then heated under from 2 to 2i atmospheres pressure for a time 

 sufficient to obtain the product desired. After inversion the material 

 is drawn off into mixing tanks and the acid is nearly neutralized with 

 sodium carbonate or a mixture of sodium and calcium carbonates. The 

 salts obtained by neutralizing the above amount of acid would be about 

 0.25 to 0.30 per cent in the finished product. This thin sirup is filtered 

 through presses and through charcoal, concentrated to about 30° 

 Baume, again filtered through charcoal, and finally concentrated to the 

 desired consistency in vacuum pans. During the final concentration 

 small amounts of acid sodium or calcium sulphite or sulphurous acid 

 may be added to produce a light-colored product. The methods of 

 procedure vary with the product to be obtained. Confectioner's glu- 

 cose must give a decided starch reaction, and the percentage of reducing 

 sugar must not be more than 48 per cent of the total solids indicated 

 by the specific gravity. With brewer's glucose a high percentage of 

 maltose is desirable; hence the dextrose will be low and the dextrin 

 also high. Mixing glucose must give no starch reaction and the per- 

 centage of reducing sugars must be between 50 and 53 per cent of the 



''Oscar Saare, Industrie der starke, und der Starke-fabrication in der Vereinigen 

 Staaten vom Amerika und ihr Einfluss auf den englischen Markt. 



