191 ] .] PUBLIC DOCUMENT — No. 31. 187 



the after-i'ipeniiiii,- stage is complete and before any signs of dete- 

 rioration appear. A variety in this condition is at the point of 

 highest dessert quality. Especial consideration will be given in 

 this discussion to the question of high quality in each variety. 



Before entering into this discussion, it may be well to con- 

 sider the relation between chemical composition and quality. 

 In the first place, it may be said that quality is used with sev- 

 eral different meanings. It may refer to the dessert quality of 

 the fruit or to its value for kitchen purposes. The apple of 

 high dessert quality is different from the apple of high kitchen 

 quality. We also speak of the shipping quality of fruit, and 

 high shipping quality is in a measure opposed to high kitchen, 

 and even more to high dessert quality. The apple which ships 

 well will usually be a fair keeper, but these two qualities are by 

 no means coincident. The chemical determinations which 

 throw the most light on quality are those of the sugars and acid 

 and of the insoluble solids, the latter being of greater impor- 

 tance than is usually considered to be the case. 



The apple of high dessert quality is low in its content of in- 

 soluble solids, this signifying a tender flesh and prol)ably thin- 

 walled cells. It is high in sugars, more particularly sucrose.' 

 The amount of acid is proportional to the quantity of sugars; 

 the higher the content of sugars the higher must be the content 

 of acid, in order to bring an agreealile blending of these two 

 constituents. If a large proportion of the sugars is sucrose, 

 the proportion of acid needs to be larger than if the proportion 

 of sucrose is low, in order to give the same quality. The ratio 

 of acid to total sugars most favorable to high dessert quality will 

 vary greatly with iutlividunl tastes. Some prefer a sweet a]i])le, 

 and, on the other hand, many like a fairly acid frnit. If the 

 sugars are in the proportion approximately of two-thirds reduc- 

 ing sugars to one-third sucrose, the following may be taken as a 

 -fair estimate of the varying ratio of total sugars to acid for 

 different flavored fruits. These ratios will not hold for fruits 

 that have eutci'cd into the stage of ]ihysiological decay. 



