BUREAU OF CHEMISTRY. 437 



from various other fruits have been continued, their nature being 

 similar to those carried on with grapes. It is found, however, that 

 each fruit presents peculiarities requiring slight modifications in 

 treatment. These results were printed in the Journal of Industrial 

 and Engineering Chemistry for July, 1909. 



It has been found that freshly pressed apple juice, cooled imme- 

 diately after preparation, can be kept for a period of from six weeks 

 to throe months at 32° F. before it begins to ferment, after which the 

 fermentation is very slow and the flavor of the juice well maintained. 

 Investigations made during the past season along this line have veri- 

 fied those previously made and show in addition that cider held at 

 the freezing point on withdrawal from storage keeps well at refriger- 

 ator temperatures. 



Another study on the value of peaches as vinegar stock was made, 

 covering the composition of peach juices of different varieties, the 

 fermentation of ground peaches, the composition of the resulting 

 ciders, and the preparation and composition of peach vinegar. It 

 appeared from this work that peaches contain sufficient fermentable 

 sugar for use in this way and that they can be successfully handled 

 by the machinery used for making apple vinegar. 



Studies on the method of preparing dried, sugared pineapples have 

 been continued and a very palatable product which keeps well has 

 been produced. The samples held in cold storage retained to a 

 great degree their original golden j'ellow color and the rich pine- 

 apple aroma and flavor. These three investigations have been re- 

 corded in Circulars 48, 51, and 57 of the Bureau of Chemistr3^ 



Further investigations on Japanese persimmons have indicated 

 that the Japanese process of ripening by using sake or dilute alcohol, 

 as the liquid with which to saturate the walls of the vessel in which 

 the fruit is stored, can be successfully applied commercially if the 

 fruits are evenly ripened. Otherwise a considerable proportion of 

 the fruit may soften unduly. 



The study of the effect of low temperatures on the life processes of 

 fruits has been continued and extended to several varieties of small 

 fruit. In this study the rate of the evolution of carbon dioxid is 

 used as a measure of physiological activity. In all cases thus far 

 investigated cooling was found to cause marked retardations in the 

 life processes. 



In collaboration with the Bureau of Plant Industry a study is also 

 being made of the composition of oranges at different stages of 

 maturity with a view to elaborating, if possible, an analytical method 

 by which data may be secured for the comparison and selection of 

 types of oranges. 



A study has been made of the practice of picking immature oranges 

 and grape fruits and sweating them for the purpose of supplying the' 

 market in advance of the time of normal ripening. It appears that 

 fruit so treated is so far inferior to that permitted to attain a rea- 

 sonable degi-ee of ripeness before picking tliat the continuance of 

 the j)ractice would be likely to work great injury to the industry. 

 These fruit studies and the following food investigations are made 

 under the direction of W. D, Bigelow. 



Citrus oils and citrus by-products. — The examination of au- 

 thentic samples of citrus oils obtained in Sicily will soon be com- 



