A STUDY OF QUALITY IN POTATOES. 



Present Estimates of Quality. 



The chemists have given no little attention to the study of potatoes 

 both as a human and as an animal food product. Recognizing that 

 the food value of potatoes is almost entirely dependent upon their 

 starch content, extensive analyses have been made to determine 

 the amount of starch in the potato and its proportion to other 

 substances and to water. The protein, starch and fat content 

 and the presence of other substances which influence flavor and 

 color, have been investigated. These studies have been of great 

 value to the potato interests, for they have not onFy shaped and 

 added to our knowledge of the potato tuber as a plant organ, but 

 they have stimulated efforts to improve the plant to the end that 

 it may yield more abundantly and give a more acceptable product 

 for human food. From both of these points of view great advances 

 have been made, for the potatoes of colonial times gave poor yields 

 and were not so acceptable for food as they are now. Through 

 the knowledge of the potato and its composition, farmers have been 

 educated to better practices and methods of tillage, storing and 

 marketing, considerations which have been extended to other 

 crops. 



It is upon the considerations of starch content and other chemical 

 properties that the estimation of quality has usually been made. 

 The standard of chemical composition is fairly adequate when 

 only the utility of potatoes for the manufacture of starch is con- 

 sidered, and perhaps also when potatoes are used only for stock 

 food. But the proportion of the country's production of potatoes 

 for starch manufacture as compared with the quantity produced 

 for food is very small; and, in addition to this, as a general rule, 

 it is the unripe and unmarketable tubers which are used for starch 

 manufacture. From the view point of the starch manufacturer, 

 the starch content of the potato would be a good and a logical basis for 

 estimating the quality; but of the 332| million bushels (332,830,300) 

 produced in the United States in 1904, only a little more than five 

 millions (5,166,666) were used in the manufacture of starch. As a 

 general rule, it is only those potatoes which are worth less than fifty 

 cents per barrel that find their way to the starch factory. The same 

 may be said also of those used for stock food. These facts apply 



