SOME CHANGES IN FLORIDA GRAPEFRUIT IN 

 STORAGE 1 



Lon A. Hawkins, Plant Physiologist, and J. R. Magness, 2 Scientific Assistant, Office 

 of Horticultural and Pomological Investigations, Bureau of Plant Industry, United 

 States Department of Agriculture 



INTRODUCTION . 



Zoller (n), 3 in his paper on the constituents of the grapefruit (Citrus 

 decumana) , has pointed out that very little attention has been paid to tht 

 chemical constituents of this important fruit. This statement might 

 also be made concerning the physiology of the fruit and the changes 

 which go on in it after it is removed from the tree and held at storage 

 temperatures. Some analyses of grapefruit have been made, however, 

 by various investigators. 



Chace, Tolman, and Munson (4) in their work on tropical fruits analyzed 

 several different varieties of grapefruit. Rose (8) and others connected 

 with the Florida Agricultural Experiment Station have made many 

 analyses of citrus fruits in working out a basis for the regulation of the 

 shipping of them. These last-mentioned analyses were for the most 

 part determinations of the acid and sugar content of the pulp or juice and 

 of the soluble solids present in the juice. 



Collison (5) determined the acids and sugars in the juice of several 

 varieties of grapefruit picked at various times during the season. He 

 found, in general, that there was a decrease in acidity and an increase in 

 sugar content as the season advanced and that after the fruit matured the 

 sucrose was gradually broken down to reducing sugars. The fruits were 

 analyzed shortly after removal from the tree. 



Shamel (9) quotes a number of analyses of Florida and California 

 grapefruit by E- M. Chace. Zoller (11) found that the acid of the pulp 

 decreased during storage and records a marked increase in sugars after 

 the fruit is removed from the tree. He found also that the content of 

 the glucoside naringin, which is the bitter principle of grapefruit, was 

 less in the peel after storage. This writer apparently used only a small 

 number of fruits in his storage experiments, the work being for the most 

 part a chemical study of the various constituents of the fruit. 



Chace and Church (j) recently made a chemical study of some different 

 types of grapefruit grown in California and Arizona. They determined 



1 This paper gives the result of a portion of the work carried on under the project " Factors Affecting the 

 Storage Life of Fruits." 



2 The writers' thanks are due Mr. L. B. Scott, formerly Pomologist, Office of Horticultural and Pomologi- 

 cal Investigations, for advice and helpful criticism while this work was in progress. 



3 Reference is made by number (italic) to " Literature cited," p. 372-373. 



Journal of Agricultural Research, Vol. XX, No. 5 



Washington, D. C Dec. 1, 1920 



vs Key No. G-213 



(357) 



