30 MASS. EXPERIMENT STATION BULLETIN 354 



storage tests are being continued. These data are not significantly' different from 

 those of Daniel and Rutherford (1936) except in the effect of darkness on ascorbic 

 acid. Their storage in the dark, using containers wrapped in black photographic 

 paper, was detrimental to the potency of the tomato juice. 



Carotene {Vitamin A) Studies 



Paralleling the ascorbic acid storage experiments, carotene determinations 

 were made on samples stored up to 400 days at room temperature and in diffused 

 light. The carotene was determined by the method of Russell, Taylor, and Chi- 

 chester (1935) as modified by DeFelice and Fellers (1938). The well-mixed 

 contents of three containers were used for analysis. 



In general, the loss of carotene in glass-packed tomato juice during storage 

 was relatively small. From an original content of 20 international units per 

 gram, tomato juice packed in amber glass containers lost 10 percent in 400 days 

 and that in flint glass lost 19 peicent in the same period. 



Apparently, light has a deleterious influence on the retention of carotene in 

 tomato juice packed in glass bottles. However, ordinary storage periods of a 

 few months should not seriously affect the carotene in the canned or bottled 

 juice. 



Variation in Commercial Brands 



Nineteen brands of commercially canned tomato juice, from the crop of 1935, 

 were tested for ascorbic acid. Results are presented in Table 14, and varied from 

 40 international units per ounce to 100 units. The determination for ascorbic 

 acid was made on one sample of each brand. In order to determine the variation 

 within a brand, it was necessary to make a more detailed study. 



Table 14. — Ascorbic Acid Content of 18 Commercial Brands of Canned 



Tomato Juice 



Variation in Samples of Same Brand 



A sample of the 1935 pack of a commercial brand of tomato juice was pur- 

 chased in each of 14 retail grocery stores, 6 in Amherst and 8 in Northampton. 

 All samples were packed in tin cans of the same size. The samples varied from 



