28 CASSAVA. 



PRESERVATION OF CASSAVA FOR MANUFACTURING PURPOSES. 



For the manufacture of starch from cassava" the fresh tubers are 

 delivered to the starch factory, and as they deteriorate rapidly after 

 being harvested it is necessary that they should be grown in the vicinity 

 of the mill. Thus the marketing of the crop is dependent upon the 

 location of the mills as well as the demand for starch, with the excep- 

 tion of the small amount that may be grown for home consumption. 

 For this reason it is desirable that some practical treatment of the 

 tubers be developed which will eliminate the necessity for immediate 

 utilization after harvesting. Experiments were conducted to demon- 

 strate the feasibility of desiccating the ground tubers in small quan- 

 tities and } r et with commercial profit. It is, of course, perfectly prac- 

 ticable to prepare cassava meal, as has been done, if a suitable form 

 of d lying kiln be available, but to erect such a kiln would require too 

 great an outlay for a farmer producing cassava on a small scale. The 

 experiments were conducted, therefore, with a view to sun-drying 

 with a minimum expenditure for equipment. 



A 2-horsepower gas engine was used for grinding, the mill consist- 

 ing of a revolving drum covered with a sheet of roofing tin punctured 

 to make a grating surface. Over this a hopper was arranged, the 

 whole resting on a suitable frame. This mill cost when complete, 

 with shaft, boxings, and pulley, $10, and would grind 1 ton of tubers 

 in one and one-half hours. Drying trays were made, consisting of a 

 framework 2^ by 5 feet with a canvas bottom, at a cost of 25 cents each. 

 As the trays were filled they were pushed out over a suitable runway, 

 after which the ground cassava was occasionally stirred with a hoe or 

 other tool. 



The actual cost of preparation as determined by the experiment was 

 $2.25 a' ton, after the laborer thoroughly understood the work, his pay 

 being $1.25 per day. At the time of the experiment the weather was 

 exceptionally unfavorable, being cloudy and threatening. Only in one 

 instance was it possible to grind roots and get the product dry enough 

 to bag it in the same day. When the drying was not completed at the 

 close of the day the trays were stacked under shelter to be put out jigain 

 the next morning. When dried under the most favorable conditions, a 

 fine white meal was obtained, but if the drying was prolonged the meal 

 was discolored. When used for stock feeding, this discoloration is not 

 objectionable. The greatest shrinkage in weight which occurred was 

 60 per cent, the meal then containing 8 per cent of moisture, and the 

 average reduction in weight was 50 per cent. 



Meal prepared in this manner and kept for eight months has shown 

 no signs of deterioration, which means that the product can be stored 



U. S. Dept. Agr., Bureau of Chemistry, Bui. No. 58, The manufacture of starch 

 from potatoes and cassava, 1900. 



