62 MASS. EXPERIMENT STATION BULLETIN 327 



Microbiology of Dried Foods. (J. A. Clague in cooperation with the 

 Department of Bacteriology. ) The number of microorganisms on dried foods 

 varies from a few thousand per gram as a maximum on dried fruits up to 

 several millions per gram on dried vegetables. 



Tests conducted with a small tunnel drier showed that artificial drying 

 effectively eliminated yeasts and materially reduced the numbers of bacteria 

 and molds on dried fruits. Reduction of the numbers of microorganisms on 

 vegetables during the drying process was not so marked as with fruits; in fact 

 dehydration alone did not completely eliminate Escherichia coli which was 

 inoculated on the vegetables, although the blanching process was efficient in 

 this respect. 



Solid media suggested for a study of dried foods are: plain nutrient agar as 

 recommended in Standard Methods of Water Analysis, and tomato agar for 

 yeasts and molds. 



The methods used in the commercial dehydration of foods should produce 

 a safe product, especially when it is considered that most of these foods are 

 cooked before being consumed. 



A paper on this study is now in press. {Food Research 1: 45-59.) 



Nutritive and Technological Studies on Fishery Products. (C. R. 



Fellers, J. A. Clague, F. P. Griffiths, W. S. Conway Jr., and V. K. Watson.) 

 Additional experiments have confirmed our previous report on the Atlantic 

 whiting as suitable for canning, flaking and chowders. This study will be ex- 

 tended to include further technological and nutritional investigations on this 

 fish. 



Part of the study of fish meal in poultry feeding has been published in Trans. 

 Fisheries Soc. 64: 293-303. 



Bio-assays of mackerel oil showed that the body oil contained about 7 U.S. P. 

 units of vitamin A per gram while the liver oil contained 25 units per gram. The 

 mackerel body oil contained no significant amount of vitamin D, while the 

 liver oil had about 25 U.S. P. units per gram. The mackerel oil when fed to 

 rats with casein or with fat-free mackerel flesh had an apparent toxic effect on 

 the rats. 



Nutritional and chemical studies on the sand crab, Platyonichus ocellatus 

 and the blue crab, Callinectes sapidus showed them to be very similar in com- 

 position and food value. The crab meat protein was found to have approxi- 

 mately the same biological value as beef protein. 



Ascorbic Acid (Vitamin C) Content of Raw, Cooked, and Canned 

 Rhubarb. (C. R. Fellers, J. A. Clague, and Walter Stepat. ) Rhubarb is a 

 good source of vitamin C. The protective level for guinea pigs is 3 to 4.5 grams 

 daily. Cooking the rhubarb into sauce causes a loss of 30 to 40 percent of the 

 anti-scorbutic factor. Rhubarb canned in water does not protect guinea pigs 

 from scurvy when fed at a daily level of 7 grams (5.3 grams of rhubarb). 

 Titration studies with 2, 6 dichlorophenolindophenol show that the titration 

 and the animal assay methods yield comparable results. This paper is now in 

 press. (Amer. Soc. Hort. Sci. Proc, Vol. 33.) 



Home Canning Research. (C. R. Fellers, A. S. Levine and W. A. 

 Maclinn.) Internal pressures in glass jars during thermal treatment in both 

 water bath and pressure cooker were determined by means of specially con- 

 structed equipment. Similarly, two methods of accurately measuring vacuum 

 in sealed glass jars have been devised, and the manuscript has been accepted 

 for publication. (Food Research 1: 41-44.) 



Two years of laboratory work and cooperative home canning in which all- 



