14 



UNFERMENTED APPLE JUICE. 



is so made that no solder comes in contact with the interior. Some 

 makers have gone a step farther and provide cans covered inside with 

 a lacquer in order to protect the goods from contamination with tin, 

 this being desired by the manufacturers not only for hygienic reasons 

 but because tin has a deleterious effect on the color of many canned 

 goods. 



Two kinds of cans were used as containers for the several varieties 

 of apple juice in this experiment. Both were of the type which prac- 

 tically excludes all metals except tin from contact with the juice. In 

 the case of those designated in Table III as "plain" cans, the juice 

 was exposed to the action of the tin; those designated as "coated" 

 were covered on the inside with a lacquer. The amounts of tin found 

 in various samples of juice and the time the sample had been in the 

 can are given in Table III. These results indicate that while the 

 lacquer was not a perfect protection it materially lessened the amount 

 of tin dissolved, the decrease being nearly 50 per cent. 



TABLE III. Tin found in canned apple juices. 



SPOILAGE. 



It has been stated (page 11) that the conditions of processing 

 were not absolutely established, since some varieties spoiled in the 

 cans, whereas others, sterilized under the same conditions, remained 

 perfectly sound. The facts observed are as follows: The cans of 

 Tolman some weeks after processing began to swell, and on opening 

 there was a considerable evolution of gas. A butyric acid odor was 

 present, and the juice had become ropy. The cans of the Shockley 

 variety began to swell, some weeks after canning, but on opening 

 showed no ropiness or bad flavor. The Rails became ropy very 

 slowly, but the flavor did not change materially, and there was no 

 evolution of gas. The Ben Davis juice also became ropy, but no 

 further evidence of fermentation was apparent, and the Gilpin juice 

 showed the same phenomenon. The canning was done in a room 

 which was used at times by others for experiments with dairy prod- 

 ucts, and it is quite possible that the juice was exposed to contami- 

 nation not usual in ordinary work. Still, the results would indicate 



