12 BULLETIN 859, U. S. DEPARTMENT OF AGRICULTURE. 



Relatively few investigations have been reported showing the pro- 

 gressive changes in composition of the tomato. Differences in com- 

 position between green and ripe fruit are given in several instances, 

 but the researches of Albahary (2) and Bigelow (11) seem to be the 

 only systematic studies of the changes occurring during development. 



Passerini (35) reports a partial analysis of both green and ripe 

 fruits of two varieties. The data, which are expressed in terms of wet 

 weight, seem to indicate that as the tomato matures there is an in- 

 crease in water and sugar and a decrease in total solids and acid. 

 Formenti and Scipiotti (19) found that the water content of the entire 

 fruit was greater in the ripe fruit than in that half ripe. Thompson 

 and Whittier (51) reported a slightly larger percentage of total 

 sugar in ripe than in green tomatoes. 



Congdon (15) reported the specific gravity of ripe and green 

 tomatoes as 1.0216 (average of eight) and 1.0230, respectively; also 

 the citric acid content as 0.528 (average of eight) for ripe and 0.990 

 for green fruit. Bigelow (11) studied the composition of tomatoes 

 (expressed juice) at different stages of maturity, but did not arrive 

 at any very definite conclusions. He states that in general the per- 

 centage of solids and sugars increases and the percentage of acid 

 decreases as the tomato becomes more mature. 



Albahary (2) has given the most complete account of the chemical 

 transformations in tomatoes during ripening. He used three succes- 

 sive stages of ripening: (1) Green fruit before seed development, 

 (2) green fruit at the time seeds were completely formed, and (3) 

 fruit which was fully ripe, and he concluded that with ripening there 

 is a progressive increase in acids, sugars, starch, and nitrogenous 

 nonprotein constituents, while proteins and cellulose diminish greatly, 

 remaining practically stationary toward the end of ripening. 



From the preceding resume of former work on the chemical com- 

 position of the tomato at different stages of its growth, it is seen that 

 there is little consistency in the results obtained. 



* The red pigment of the tomato is not estimated in any of the 

 routine analyses. It has been isolated by several workers, who found 

 that the amount recoverable was 0.2 per cent of the dry weight of 

 the fruit or less. Its preparation in pure crystalline condition was 

 first accomplished in 1876 by Millardet (31), who named it solanoru- 

 bin. After it had passed into the synonymy of carotin, it was again 

 isolated, in 1903, by Schunck (45), who renamed it lycopin. Mon- 

 tanari (32) made the first analysis and proved that it was a hydro- 

 carbon. The final identification of lycopin as an isomer of carotin 

 was made by Wills tatter and Escher (58). In 1913 Duggar (17) 

 studied the effect of conditions upon the development of the tomato 

 pigmentation and found the color of the ripe fruit to depend (1) 

 upon the presence or absence of lycopin in the flesh (in the absence 

 of red lycopin the nesll is yellow, due to carotin and possibly xantho- 



