ASCORBIC ACID IN TOMATOES 33 



weather during the growing season. Husseman (1937) in 1936 found little ascorbic 

 acid in Wisconsin tomatoes but presents no data. 



No correlation was found between size of a tomato and its ascorbic acid content. 

 These results are not in agreement with those of McHenry and Graham (1935). 

 These authors explained the difference in ascorbic acid content of diploid and 

 tetraploid number tomatoes as the result of fruit size. 



The ascorbic acid concentration was consistently higher in the locule section 

 of the one variety tested than in any other part of the fruit. However, the out- 

 side flesh and skin contributed the greatest quantity of ascorbic acid to the 

 tomato as a whole. Krauss, Washburn, and Hoffman (1937, 1938), and Hoff- 

 man 3 reported that varieties differed in their quantitative distribution of ascorbic 

 acid. 



Six varieties showed no significant increase in ascorbic acid content during the 

 ripening process from the hard green stage to the hard ripe stage. Clow and 

 Marlatt (1930), House, Nelson, and Haber (1929), Krauss, Washburn, and 

 Hoffman, (1937, 1938), and Hoffman^ found a close correlation between the 

 stage of maturity and the ascorbic acid potency. 



Parchment wrappers evidently do not influence the ascorbic acid content of 

 shipped tomatoes. Storage of ripe tomatoes of two varieties for 240 hours at 

 room temperature caused no apparent loss of ascorbic acid. No definite data 

 have been reported previously on this subject of storage of fresh, ripe tomatoes. 



The manufacture and canning of tomato juice was found to be destructive to 

 ascorbic acid only in a step of the procedure not common to commercial practice, 

 concentration of the pulped juice. Homogenization, a process often used in the 

 commercial manufacture of tomato juice, was found by Barnby and Eddy (1932) 

 and Fellers et al. (1935) to cause no destruction of ascorbic acid. Theoretically, 

 then, commercially canned tomato juice should be as antiscorbutically active 

 as the tomatoes from which it was extracted. Actually, the large quantities 

 prepared commercially necessitate a slow canning process, which results in de- 

 struction of ascorbic acid from prolonged contact with the air. The problem of 

 increasing the ascorbic acid content of commercial tomato juice may lie in the 

 direction of a tomato breeding program rather than in a revamping of the canning 

 procedure. 



Considerable variation was found in the ascorbic acid content of commercial 

 brands of tomato juice. These results are in agreement with those of Fellers, 

 Clague, and Isham (1935) and Connecticut Experiment Station Food Products 

 Reports (Bailey, 1937, 1938). Variations in samples of the same brand again 

 indicate that representative samples are difficult to obtain. 



Storage of tomato juice in three types of containers for 400 days at room tem- 

 perature resulted in a loss of not more than 25 percent of its ascorbic acid content. 

 The data do not indicate significant differences between storage in tin or glass 

 containers. Daniel and Rutherford (1936) and Hauck (1938) found less loss on 

 storage of tomato juice in tin cans than in glass containers. Hauck showed that 

 storage in glass containers under light or dark conditions resulted in no variation 

 of ascorbic acid content, thereby agreeing with the data in Table 13. Daniel and 

 Rutherford, however, found storage in containers wrapped in black photographic 

 paper to be detrimental. 



Opened containers of tomato juice were stored at cold and at room temperatures. 

 More destruction occurred at room temperature than at 5° C. Hauck confirmed 

 the 10 to 15 percent loss of ascorbic acid found after 44 hours storage at refrig- 

 erator temperature. 



'Hoffman, I. C, 1937. Personal communication. 



