ENOLOGICAL STUDIES. 



THE OCCURRENCE OF SUCROSE IN GRAPES. 



OPINIONS FROM THE LITERATURE ON THE COMPOSITION 



OF GRAPES. 



It has been generally stated throughout the literature that sucrose 

 does not occur in grapes. While no actual data have been found on 

 investigations made in foreign enological laboratories dealing specifi- 

 cally with the point, the following statements on the subject of the 

 composition of grapes and wine are of interest in this connection. 



J. L. W. Thudichum 1 says that cane sugar (sucrose) has never been 

 found in grapes. Babo and Mach 2 say that while the presence of 

 sucrose in grape must has been claimed, these observations are to be 

 considered incorrect. Again, it was stated in 1910 that sucrose is 

 not found in the grape. 3 Lucien Semichon, 4 director of the enological 

 station of the Aube, enumerates the sugars present in the must of 

 grapes as glucose, levulose, and invert sugar, but does not mention 

 sucrose. J. Laborde, 5 professor of the institute of viticulture of the 

 Gironde, discussing the nature of the sugars in grapes, mentions the 

 researches of Mach, Bouffard, Dougast, and Pousset, and of Aime 

 Girard and Lindet, and notes the presence of dextrose and levulose 

 only in the sugar content of grapes. Victor Sebastian 6 says the 

 juice of the grape does not contain saccharose (sucrose). H. C. Gore, 7 

 in an article on the composition of Scuppernong, Concord, and Ca- 

 tawba grape juices, etc., notes the occurrence of sucrose in two of 

 the three kinds of Scuppernong 8 grapes analyzed. His data shows 

 0.07 per cent in one variety and 1.90 per cent in another when 



1 A Treatise on Wiues, London, 1S90, p. 95. 



2 Weinbiru und Kellerwirtschaft, Berlin, 1896, 3d ed., v. 2, p. 2. 

 ' Kellerwirtschaft, 1910, 4th ed., v. 2, p. 3. 



< Traite" des maladies des vins, Montpellier, France, 1905, p. 2. 



5 Cours d'oenologie, Paris, 1907, pp. 9-10. 



6 Traite" pratique de la preparation des vins de luxe, Montpellier, France, 1909, p. 84. 

 i J. Ind. Eng. Chem., 1909, 1 (7) : 436. 



8 " Scuppernong" is, strictly speaking, a variety of the Rotundifolia species but the term is applied to 

 all lighter colored varieties of Rotundifolia; the other two varieties examined were the Jain es and the 

 Mish, sucrose being found also in the latter. 



7 



