1{ 



MASS. EXPERIMENT STATION BULLETIN 354 



method for determining ascorbic acid is used in all the following tomato inves- 

 tigations as it corresponds more closely to the biological values. When the 

 modified iodine method is used, all figures must be multiplied by the factor 0.7. 



Table 2. — Comparison of Dye and Modified Iodine Methods for 

 Determining Ascorbic Acid in Recanned Tomato Juice 



Storage Period 

 Days 



1-30 



31- 60.... 



61- 90 



91-121 



Average . 



♦Ascorbic Acid, Average Mg. per Cc. 



♦Titrations were made daily, and 3 determinations were made on each sample. 



300 



40 60 



Time in Days 



Figure 1. Biological Assay for Ascorbic Acid in Recanned Tomato Juice. 

 Weight gains and scurvy scores of guinea pigs. 



Tomato luice Fed Scurvy Score 



A 7.50 cc. 



B 7.00 cc. 



C 6.50 cc. 1.8 



D ■ 5.75 cc. 3.2 



E.' .'.'.'! 5.00 cc. 4.2 



F (negative control) none 11 



G (positive control) fed 3 cc. canned grapefruit juice 



