A CHEMICAL STUDY OF CRANBERRIES 



By F. W. Morse,' Research Professor of Chemistry 



Introduction 



The value of the crop of cranberries produced in Massachusetts is around 

 four million dollars annually. Their production, moreover, increases the value 

 of land for the conununity in a striking degree. A peat swamp that is nearlj' 

 worthless for farming or forestry becomes valued at one thousand dollars 

 per acre when transformed into a cranberry bog. 



Cranberries have occupied very little space in the literature of foods and 

 nutrition. Wiley (13)- mentions them in a paragraph and gives a partial 

 analysis. They are included in tables by Sherman (12) and Rose (11). Not 

 many references to the American cranberry, Vaccmium macrocarpum, are to 

 be found in the literature of chemistry, and several of them originated at this 

 Experiment Station. European references usually mean either Vaccinium 

 vitis idaea or ^''acci7lium oxi/coccus, the Preisselbeere and Moosbeere respec- 

 tively. 



Griebel (6) gives two analyses of T^. mdcrucarpum stated to have been 

 grown in Germany. Bigelow and Dunbar (1) and Nelson (10) have deter- 

 mined the proportions of citric and malic acids occurring in cranberries. Ma- 

 son (8) and several others have measured the amount of benzoic acid which 

 they contain. Culpepper and Caldwell (5) included cranberries in their study 

 of discoloration of canned fruit. 



The chemical studies included in tliis article deal with the changes in 

 composition of the fruit as the berries develop on the vines before harvesting 

 and while held in storage for the market, and show the composition of many 

 of the numerous varieties grown in this State, New Jersey and Wisconsin. 



It is necessary to present first the studies of the ripening cranberry and 

 of the stored fruit, since the range in composition of the varieties may be in 

 part dependent on the maturity of the sample when picked from the vines or 

 the length of time it was in storage. 



Changes in the Composition of Cranberries during Ripening on the Vines 



The two most widely grown varieties of Cape Cod cranberries. Early 

 Black and Howes, were under observation during the ripening periods of 

 1926 and 1927. The berries that served for our studies were grown at the 

 cranberry experiment station in East Wareham. 



1 The aid of the cranberry growers who supplied samples of their pi'oduct, and the 

 financial contribution of the American Cranberry Exchange are gratefully acknowledged, 

 and their spirit of cooperation is highly appreciated. The author also acknowledges the 

 assistance of C. P. Jones of the Research Laboratories, who made the determinations of 

 total sugar and starch in the samples of 1926 and 1927, and of Philip H. Smith of the 

 Feed Control Laboratory, who supervised the fiber and protein determinations. The co- 

 operation of the Department of Pomology by putting its cold-storage facilities at our 

 service was an important factor in the studies. 



- Fig-ures in parentheses refer to literature cited on page 100. 



