ASCORBIC ACID IN TOMATOES 3 



determined; but when it became necessary to interpret data, every effort was 

 made to do this consistently and logically. 



The description and identification of the tomato or tomato product in Table 1 

 is that given in the report from which the data were taken. In a large majority 

 of cases, however, little information other than the product used was given and 

 in the processed tomato lack of standardized procedures makes interpretation 

 difficult. 



Unless otherwise stated, the methods employed in the work reviewed here 

 are the biological assay method of Sherman, La Mer, and Campbell (1922) or the 

 chemical titration method using 2, 6-dichlorophenolindophenoI. 



Raw Tomatoes 



The influence of chromosome number on the ascorbic acid content of the 

 tomato has been the subject of considerable discussion in the literature. Key 

 (1933) found that tomatoes of the same genetic constitution, whether of diploid 

 (12 pair) or tetraploid (24 pair) chromosome number, contained equal quantities 

 of ascorbic acid. Sansome and Zilva (1933, 1936) found that tomatoes with 

 tetraploid number of chromosomes have approximately 40 percent more ascorbic 

 acid than those of the diploid chromosome number. McHenry and Graham 

 (1935) stated that chromosome number does not influence the ascorbic acid 

 content of tomatoes. They claimed that the differences found by other authors 

 were due to fruit size, as the tetraploid tomatoes are usually smaller than the 

 diploid tomatoes. Consequently, the ascorbic acid is more concentrated per unit 

 of weight in the smaller tomatoes of the same genus. Lindstrom,! in a personal 

 communication, stated that all cultivated varieties of tomatoes are of the diploid 

 type, having 12 pairs of chromosomes. He also noted that, although it is not 

 difficult to obtain a tetraploid of any variety, they are not practical as the fruit 

 or seed set is poor. 



Tripp, Satterfield, and Holmes (1937) studied the ascorbic acid content of 10 

 varieties generally produced in North Carolina. The varieties in which the 

 ascorbic acid content was highest were Pritchard (0.218 mg. per gram) and the 

 Louisiana Pink (0.217 mg. per gram). In descending order of ascorbic acid content 

 the other varieties tested were: Greater Baltimore, Break-o'-Day, Scarlet Dawn, 

 Grothen, Louisiana Gulf State, Walter Richards, and Marglobe. The John Baer 

 variety showed the smallest amount of ascorbic acid (0.148 mg. per gram). 

 These investigators found no constant relation between the size of the tomato 

 and its ascorbic acid value. 



Krauss, Washburn, and Hoffman (1937), and Hoffman^ tested 71 varieties 

 and strains for ascorbic acid but gave no data in their preliminary reports. They 

 stated that rather wide differences were found among the varieties regardless of 

 color; this confirmed their observations of the previous year, that color, per se, 

 is not associated with ascorbic acid. Stage of maturity and acidity were found 

 to be closely correlated with ascorbic acid potency. Acidity increased rapidly 

 as the fruits reached full size, but decreased somewhat during the ripening process. 

 Ascorbic acid increased with acidity within the variety. During the ripening of the 

 fruit there was a small reduction in the quantity of ascorbic acid, accompanying 

 a small loss in acidity, but during the final softening of the ripe fruits the ascor- 

 bic acid content again increased rapidly. These investigators also found that 

 different soil types produced little or no change in ascorbic acid content if well 



•Lindstroni, E. W., 1936. Personal communication. 

 'Hoffman, I. C, 1937. Persona! communication. 



