CHANGES DURING THE SPOILAGE OF TOMATOES. 



acid was added gave a strong precipitate with calcium acetate. 

 There is, therefore, less than 0.01 per cent of oxalic acid in tomatoes. 



(2) Tomato juice tested for malic acid by the optical method with 

 uranvl acetate (Circular 76, Bureau of Chemistry) gave a negative 

 result. As this method is easily capable of detecting 0.02 per cent 

 of malic acid, there must be less than this quantity present hi tomato 

 juice. 



(3) The acids in the juice of fresh tomatoes were precipitated with 

 a lead acetate solution, the precipitate was well washed with hot 

 water, decomposed with hydrogen sulphid, the lead sulphid removed, 

 and the barium salts of the acids prepared; 0.6870 gram of the barium 

 salt, dried at 110 C., gave 0.6100 gram of barium sulphate, barium 

 found, 52.3 per cent; calculated for Ba 3 (C 6 H 5 O 7 ) 2 , barium equals 52.15 

 per cent. 



(4) The acids extracted from a tomato juice acidified with sulphuric 

 acid by long extraction with ether gave in a 0.01 per cent solution in 

 water a very strong precipitate with the Deniges reagent. The acids 

 so extracted when in 10 per cent aqueous solution give no tests for 

 malic or tartaric acids. 



(5) Sound tomatoes contain no volatile acids. This question was 

 tested on a very large number of samples of tomatoes of different 

 origin, always with negative results. 



Some idea of the general cause of tomato spoilage may be obtained 

 by the following experiments: 



Determinations on fresh and spoiled tomatoes. 



The volatile acids were converted into the barium salt; barium, 

 43.6 per cent; calculated for barium butyrate, Ba(C 4 H 7 O 2 ) 2 , 44 per 

 cent. The volatile acids in the first case contained large amounts of 

 butyric acid, and in the second case they consisted almost entirely of 

 butyric acid, as was evident from the odor and from the odor of the 

 ethyl ester which was prepared from these volatile acids. It appears 

 that butyric acid is a rather common decomposition product when the 



