ANNUAL REPORT, 1939 75 



acetic acid was more toxic than either lactic or hydrochloric acid to Salmonella 

 aertrycke, Saccharomyces cereviseae, and Aspergillus niger. These organisms were 

 inhibited in growth or destroyed at a higher pH value when acetic acid was used 

 as the toxic agent than when lactic or hydrochloric acid was used. The mold 

 utilized relatively high amounts of lactic acid to develop a luxurious growth 

 heavier than that obtained from the acetic acid or the hydrochloric acid series. 

 The toxicity of acetic acid to various microorganisms is not due to the hydrogen- 

 ion concentration alone, but seems to be a function of the undissociated acetic 

 acid molecule also. 



Nutritional Studies on Spinach. (C. R. Fellers and C. F. Dunker.) These 

 studies were reported in a paper entitled "Vitamin C Content of Spinach," pub- 

 lished in the Proceedings of the American Society for Horticultural Science 36 

 (1938):500-504, 1939 (Contribution 339). 



Factors Influencing Nutritive Value of Snap Beans. (C. R. Fellers and K. T. 

 Farrell.) The vitamin Bi content of snap beans was 3.5 I. U. per gram, on a 

 moisture-free basis. Freezing apparently had little effect on this vitamin unless 

 the blanching process was omitted, when there was a 40 percent loss. Snap 

 beans canned in glass or tin suffered a 20 percent loss. While frozen blanched 

 beans lost very little vitamin Bi in 12 months' storage, the canned products 

 showed a 40 percent decrease. 



Freezing and canning had little effect on the vitamin B2 content of snap beans. 

 The average value was 7 Bourquin-Sherman units per gram. 



Vitamin C in the fresh snap beans averaged 2.8 I. U. per gram, on a moisture- 

 free basis. A 32 percent loss occurred during freezing, whereas canning resulted 

 in a 75 percent loss. There was no significant loss in the canned or frozen product 

 after 12 months' storage at 45° F. 



If the juice from the cans is discarded, 20 to 50 percent of the water-soluble 

 vitamins go with it. The type of container, i. e., glass or tin, showed no marked 

 effect in any of the assays. 



Fruit, Vegetable, and Other By-Products. (C. R. Fellers, K. G. Shea, and 

 Wm. B. Esselen.) In order to determine the possible feed value of dried tomato 

 pomace, a waste product from the manufacture of juice and pulp, chemical and 

 biological analyses were made. A report of the work was published in Poultry 

 Science 18:45-47, 1939 (Contribution 310). 



A study of dried corn distillers grains and concentrated slop was also reported 

 in Poultry Science 18:89-95, 1939 (Contribution 311). 



Active work now under way indicates that cocoa shell meal is approximately 

 one-third as valuable as cod liver oil as a source of vitamin D for rats. The 

 riboflavin content is also appreciable. It seems possible that this waste product 

 of the cocoa industry may become a useful component of poultry rations. 



Food Value of Potatoes. (C. R. Fellers and Mary E. Lyons.) This investiga- 

 tion has been continued and the results published in American Potato Journal 

 16:169-179, 1939 (Contribution 346). 



Use of Corn Sugar in Foods. (C. R. Fellers, A. S. Levine, and L. Tarkow.) 

 Results are reported in a paper, "Dextrose in the Food Industries," published in 

 American Journal of Public Health 29:135-138, 1939 (Contribution 322). 



Iron Availability Investigation. (C. R. Fellers and W. H. Hastings.) The 

 availability of iron in such foods as haddock, peas, asparagus, and broccoli is 

 uninjured by commercial freezing methods. The effect of the canning process 

 is variable, and work is under way to study further the availabity of iron in 

 canned foods. 



