THE MANUFACTURE OF FOODS 375 



What temperature does this correspond to (see Steam Tables, 

 Art. 155)? Under these conditions the conversion is rapid. 

 When the starch has disappeared, the liquid is blown by the 

 steam pressure into the NEUTRALIZER (Fig. 260) where soda is 

 added to neutralize the acid used in the conversion. The neu- 

 tralization forms salt as one product of the chemical reaction. 

 The salt remains in solution in the glucose, but there is so 

 little of it that it is not noticed in the final product. After 

 neutralization the liquid, which is cloudy because of impurities, 

 is filtered, first, through great suspended bags called bag filters, 

 then through BONE CHAR. Bone char, as its name indicates 

 is made by charring bones. When liquid is filtered through the 

 bone char, the impurities are absorbed into the pores of the 

 char while the clear liquid runs on through. The bone-char 

 filters are great tanks filled with the char, and through the 

 char, the liquid is forced. The glucose liquid comes from the 

 filter, bright and clear, but much thinner than the syrup used 

 on the table. The liquid is next concentrated by evaporating 

 a part of the water in EVAPORATORS. Here evaporation is 

 carried out at a low temperature so as to prevent the 

 darkening of the syrup. Evaporation at a low temperature is 

 accomplished by reducing the pressure of the steam within the 

 evaporator. (See Art. 155 for corresponding temperatures and 

 pressures.) After the required amount of evaporation, the 

 liquid is placed in barrels and cans for delivery to the consumer. 

 Grape sugar is made by evaporating the syrup still further and 

 subsequently crystallizing the sugar. 



Aside from its use as a table syrup, glucose is used in 

 making jellies, preserves, and candy. Large quantities are 

 used for the last-named purpose. Many medicines contain 

 glucose syrup as body. 



426. Sugar. Sugar is one of the most widely used foods. 

 There are but few manufactured foods found in the markets 

 which are as nearly pure as sugar. While the term "sugar" 

 is usually taken to mean the common article of food of the 

 table, it will be remembered that there are several kinds of 



