UNITED STATES DEPARTMENT OF AGRICULTURE 



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% BULLETIN No. 952 fcm 



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Contribution from the Bureau of Plant Industry 

 AVM. A. TAYLOR, Chief 



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Washington, D. C. 



PROFESSIONAL PAPER 



June 4, 1921 



COMMERCIAL UTILIZATION OF GRAPE POMACE 

 AND STEMS FROM THE GRAPE-JUICE INDUS- 

 TRY/ 



P>y Frank Rabak, Chemical Biologist, and J. H. Shradeb, Chemical Tech- 

 nolOf/ist, Office of Drug, Poisonous, ami Oil Plant Investigations. 



CONTENTS. 



Page. 

 The conservation of fruit-product 



wastes - 1 



Accumulation and present disposal 



. of grape waste 2 



Available quantity of grape waste 4 



Commercial products obtainable from 



grape waste 4 



Cream of tartar from grape stems •"> 



Preparation of grape pomace for the 



manufacture of jelly and oil 6 



Making jelly from grapi^ skins 10 



Page. 



Quantity and value of jelly and 



residue i:} 



Manufacture of oil from grape 



seeds 15 



Extracting tannin from the hulls 17 



Quantity, uses, and valu(> of the oil, 

 oil cake, and tannin extract from 

 grape seeds 18 



Gross returns and net profits from 



the undertaking 20 



Summary 22 



Literature cited 23 



THE CONSERVATION OF FRUIT-PRODUCT WASTES. 



FOR MANY YExVRS the cultivation of grapes for the produc- 

 tion of grape juice has been an industry of hirge and growing 

 proportions, and with the increasing popularity of the juice as a 

 beverage the industry has received added impetus. In the process 

 of preparing the juice for market large quantities of stems and 

 pomace result, which at present are practically waste material. 



In several publications of the Ignited States Department of Agri- 

 culture (13, 1-i, 15, IG)- it has been shown that in preparing products 

 for market from such fruits as cherries, raisins, peaches, apricots, 

 and tomatoes the waste resulting from the various processes is capa- 



1 The writers wish to express their thanks to Mr. .1. I). Mclntyre, Chemical Lal)ora- 

 torian of the Office of Drug. I'oisonous, and Oil riant Investigations, for valual>le assist- 

 ance rendered during- tlie couise of this investigation. 



^ The scnial numbers in parentheses reifer to " Literature cited " at the end of this 

 bulletin. 



308-120—21 1 



