EFFECT OF BENZOATE OF SODA AS A PRESERVATIVE. U> 



and displacing the air above the juice by the gas. This bottle was 

 also tightly stoppered and the two were kept side by side in the 

 laboratory. The following observations were made : 



After three days a slight growth was observed on the surface of 

 the juice which was untreated with carbon dioxid; no growth was 

 apparent on the juice treated with gas. 



On the following day thirteen colonies, several of which showed 

 greenish groups of spores, were found on the untreated apple juice; 

 none was found on the surface of the other. On June 8, three days 

 later, there was a much greater development of spores and mycelia 

 on the surface of the untreated apple juice, which had a flavor sug- 

 gesting rotten apples. On the surface of the other juice there were 

 found several filmy growths, but no development of organisms 

 giving a disagreeable flavor. On removing the stopper there was a 

 slight gas evolution and the liquid evolved carbon dioxid slowly, 

 indicating that alcoholic fermentation was starting. No unpleasant 

 flavor was apparent. A repetition of the experiment gave similar 

 results, namely, the suppression of mold growths. It would probably 

 be possible, in case the product is sold at soda fountains from small 

 kegs, to saturate the juice and fill the air space above it with carbonic- 

 acid gas, thus suppressing the development of the mold for a limited 

 time. 



Another method of eliminating mold on the surface of the liquid, 

 or preventing fermentation, would be to open the package under 

 sterile conditions and insert a sterile faucet such as has been described 

 by Dodson a of the Louisiana experiment station. This spigot is 

 so arranged as to allow the entrance of air during the outflow of the 

 liquid, the incoming air being filtered through cotton. If such a 

 faucet is used for apple juice, however, it must be made of porcelain 

 or wood. 



EFFECT OF BENZOATE OF SODA AS A PRESERVATIVE. 



Apple juice at present is largely sold in bulk, using a small amount 

 of benzoate of soda to retard fermentation, one-tenth of 1 per cent 

 being tolerated by regulation in the United States. An experiment 

 was carried on to determine the effect of sodium benzoate when added 

 in varying amounts to apple juice, with a view to finding out how 

 long such juice would keep and what quality of juice resulted after 

 standing for different lengths of time. For this purpose five 10- 

 gallon kegs which contained sterile apple juice were opened and a 

 a culture of a pure yeast, supplied by W. B. Alwood, was added to 

 each keg. Varying amounts of benzoate of soda were added and the 

 kegs were kept nearly full and closed by tightly fitting cotton plugs. 



Louisiana Agr. Exper. Stat., 1903, second series, Bui. No. 75, p. 256. 



