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The World's Commercial Products 



RICE STARCH 



The grains of the rice plant, which is grown in enormous quantities in irrigated fields in 

 tropical and sub-tropical countries, (see special article on " Rice ") are very rich in starch, 

 containing over seventy-five per cent, of the material. It is one of the principal sources of 

 laundry starch. In this case, soaking the grain and afterwards subjecting it to a bruising 

 process is not sufficient to separate the starch, and the rice is therefore previously treated 

 with a weak solution of caustic soda, which softens the grain and causes it to swell. It is then 



washed with clean water, and subsequently ground 

 between millstones and brushed through ■ sieves 

 to remove foreign particles. The fine rice flour 

 is again treated with the alkaline solution, in 

 which it is vigorously agitated for some twenty- 

 four hours. It is allowed to settle, when the 

 supernatant liquid containing the gluten in solution 

 is drawn off, and the starch collected and washed 

 in water.. It is allowed to settle and is finally 

 dried. 



An acid process is also employed in the manu- 

 facture of rice starch. The grain is soaked and 

 ground between rollers, and treated with a dilute 

 solution of muriatic or hydrochloric acid, which 

 dissolves away the non-starchy constituents, 

 leaving the starch only to settle in the tanks. 



WHEAT STARCH 



Wheat Starch is largely used in the textile 

 industries as a thickener for applying dyes to the 

 fabric. Three principal methods have been em- 

 ployed for obtaining the starch, which exists in 

 the grain to the extent of from fifty to seventy- 

 five per cent. In one method the starch is 

 obtained from the flour, which is kneaded into a 

 stiff dough with water, and after a short period, 

 about one or two hours, washed in a sieve with 

 water until all the starch has escaped through the 

 meshes as a milky fluid. The starch is allowed to 

 settle in tanks and after being purified by several 

 washings, is ready for drying and packing. This 

 process possesses an advantage over the next, 

 inasmuch as the gluten of the dough is not de- 

 stroyed but is available for commercial purposes. 

 In the second process this is not the case, for the starch is obtained by allowing 

 the wheat to ferment, resulting in the destruction of the gluten. The grain is first 

 soaked in water for a few days, the period being longer in winter than in summer, 

 and then the foul water is drawn off and clean supplies admitted. The grain is crushed 

 between rollers and allowed to ferment for about a fortnight, the process involving the destruc- 

 tion of the gluten and the liberation of the starch grains. The starchy mass is afterwards 

 transferred to a revolving drum through the perforations of which the starch escapes, as a result 

 of continual stirring, into tanks placed underneath. - The purification of the starch is effected 

 by repeated washings with pure water. 



BANANAS 



