60 PLANT COMPOUNDS 



With alkalies and alkaline earths sucrose forms saccha- 

 rates, or "sucroxides," those of calcium being the most im- 

 portant. There are three compounds with calcium : Mono- 

 calcium saccharate, Ci2H 2 iOn.CaOH; dicalcium saccharate, 

 Ci 2 H 2 oOn.2CaOH; tricaleium saccharate, Ci 2 Hi 9 On.3CaOH. 

 The monocalcium compound is readily soluble in water, the 

 tricaleium compound difficultly soluble. The latter is used 

 commerically in the separation of sucrose from beet molasses. 

 The molasses is treated with freshly burned lime. The 



1/ 



resulting precipitate of tricaleium saccharate is filtered, 

 washed with cold water and decomposed by carbon dioxide 

 in aqueous suspension. The reaction is as follows: 



Ci 2 Hi 9 On.3CaOH + 3C0 2 = C 12 H 2 20ii + 3CaC0 3 . 



Many other saccharates are also formed, such as those of 

 iron, aluminium, nickel, and copper. Those of iron are used 

 medicinally. 



Pure sucrose is prepared by precipitating it from a solu- 

 tion of commercial sucrose with cold, absolute alcohol, and 

 washing the fine crystals with absolute alcohol. Commerical 

 sucrose is made from sugar cane by squeezing out the juice 

 in mills, clarifying with lime to remove impurities, evapo- 

 rating the filtrate, and finally crystallizing out the sucrose. 

 Fig. 14 shows the interior of a sugar factory where the cane 

 juice is being evaporated. Further solution, treatment 

 with lime and bone black, and recrystallization yields the 

 pure granular sugar (sucrose) of commerce. Brown sugar 

 is obtained by evaporating to dryness the mother liquor 

 from which no sucrose will crystallize. Brown sugar origin- 

 ally contained some caramel because the evaporation of the 

 syrup was carried on in vats heated by a free flame, and part 

 of the material, being overheated, caramelized. Modern 

 evaporators are steam-heated vacuum pans, and thus 

 caramelization is avoided. 



From the sugar beet, sucrose is made by slicing the beets 

 and soaking them in water, thus allowing the sucrose to 

 diffuse gradually out of the beet cells. The concentrated 

 juice is clarified and purified much as in the case of sugar 



