10 MASS. EXPERIMENT STATION BULLETIN 354 



juice may be effectively de-aerated by warm vacuumization before canning. 

 Kohman, Eddy, and Gurin (1933) showed that when the freshly expressed juice 

 is quickly heated to boiling in shallow layers, the inert gases present scrub out 

 the oxygen. Naturally, destruction of ascorbic acid by oxidation is diminished. 

 Barnby and Eddy (1932) and Fellers, Clague, and Isham (1935) were unable to 

 demonstrate any losses in tomato juice due to mechanical dispersion by homo- 

 genization. The juices obtained by straining either home-canned or commercially 

 canned tomatoes through a sieve compared favorably with the best commercially 

 canned tomato juices according to Fellers, Clague, and Isham (1935). The 

 Marglobe variety of tomato yielded juice of a somewhat higher potency than the 

 Stone variety. These investigators correlated a pleasirtg taste with the ascorbic 

 acid content of commercially canned tomato juices, all but one of which were 

 satisfactory antiscorbutics. They also found considerable annual variation in 

 the brands. A Connecticut Experiment Station Food Products Report (Bailey, 

 1937) indicated a variation of from 0.12 to 0.32 mg. of ascorbic acid per gram in 

 12 samples of commercially canned tomato juice. A report by Bailey (1938) 

 showed the same variation in 25 samples of commercially canned tomato juice. 

 Barnby and Eddy (1932) found no differences in the ascorbic acid content of 

 the same batch of tomato juice canned in tin and glass containers. Husseman 

 (1936) reported that tomato juice in bottles, sealed with corks and paraffin, lost 

 a part of its potency to prevent scurvy. The shape of the bottle and type of 

 glass did not influence losses. Hauck (1938) and Daniel and Rutherford (1936) 

 found that ascorbic acid losses were greater when the juice was canned in glass 

 than when canned in tin. Also storage loss was greater in glass jars than in tin 

 containers. 



METHODS USED IN DETERMINING ASCORBIC ACID 

 IN TOMATOES AND TOMATO PRODUCTS 



Biological 



Following the method of Sherman, La Mer, and Campbell (1922), young 

 guinea pigs, weighing from 250 to 350 grams each, were fed the basal diet and 

 water ad libitum. This diet, generally accepted as adequate except for ascorbic 

 acid, consisted of the following ingredients: 



Baked skimmed milk powder , 15.00 parts 



Rolled oats 14.75 " 



Bran 14.75 " 



Butter 4.50 " 



Cod liver oil (not included in the Sherman diet) .... 0.50 



Sodium chloride 0.50 



The animals were housed in individual cages with raised bottoms made of J^-inch 

 sand screen to allow the droppings to pass through into trays below. 



The material to be tested for ascorbic acid was fed daily, six times a week, for 

 a period of 90 days. Three animals were placed on each level of feeding as a check 

 in case one animal became ill from causes other than ascorbic acid deficiency. 



Autopsies were performed on all animals at death. If the animal survived the 

 90-day feeding period, it was chloroformed and the autopsy then performed. 

 The severity of the scurvy lesions was scored according to an arbitrary system 

 proposed by Sherman et al. (1922). This numerical score is based on autopsy 

 findings of weakness in the bony system (joints, ribs, jaw, and teeth) and hemor- 



