ANNUAL REPORT, 1938 37 



half was cooked and then dried. At intervals of ninety days for three hundred 

 and sixty days, samples of both canned and frozen peas were brought out of 

 storage. Half of each sample was dried at low temperatures while the second 

 half was dried after cooking as indicated above. 



Results obtained from the proximate analysis gave onl\- general information 

 regarding these samples. The amounts of moisture, nitrogen, ether soluble 

 material, and crude fiber did not vary a great deal. The percentages of nitrogen 

 were somewhat lower in the canned product, either raw or cooked; but these 

 differences were not to be regarded as really significant. For the purpose of this 

 problem, cooking waters were not included in the work being reported here. 

 Since it is probably a home practice to keep cooking waters this may account for 

 these differences. An unexplained fact is that the ash content of the samples 

 after storage, either in cans or frozen, was higher than in the original sample. 

 This cannot be a difference in the samples as they had the same origin. 



The second method of analysis (Horwitt, Cowgill and Mendel) considered 

 soluble nitrogen, insoluble residue and the insoluble ash, using H.jO, N/10 HCl, 

 0.50 percent Na •> CO3 , N/10 HCl + 20 mgs. pepsin, and 0.50 percent Na ., CO3 +50 

 mgs. trypsin as solvents. It was interesting to note that in the uncooked samples, 

 either canned or frozen, the first three solvents (H.jO, N/10 HCl, and 0.5 percent 

 Nag CO 3) gave much higher results than the cooked ones. When the acid and 

 carbonate were used with the enzymes, the nitrogen of the cooked samples was 

 the more soluble (or digestible) in all but five out of eighteen samples. The dif- 

 ferences in these five samples were not large enough to be significant. 



The residue insoluble in these solvents, as well as the ash insoluble in them, 

 was higher in the cooked than in the raw samples regardless of storage. If sol- 

 ubility means digestibility, this would indicate that a larger amount of the organic 

 and inorganic residue is available in these raw samples. 



This study is to be the basis for further work with other kinds of foods. 



Changes in Meat Stored in Frozen Condition. (W. S. Ritchie.) The samples 

 originated with feeding trials at Purdue University, in which a standard corn 

 ration (corn and tankage) was fed to hogs and compared with one where the 

 corn was replaced by hominy. Samples were made available as follows: 



1. Immediately after slaughtering. 



2. After the customary storage for ten days. 



3. After being stored frozen for three months. 



4. After being stored frozen for six months. 



5. After being stored frozen for nine months. 



The samples were frozen and stored by the Birds Eye Frosted Foods, of Boston, 

 and sent to this laboratory at intervals of three, six and nine months. 



In order to indicate and perhaps evaluate any changes either in their chemical 

 composition or in their nutritive value, the samples were all subjected to the same 

 procedures of chemical analysis, vitamin bio-assays (B^ and G), and such other 

 determinations as might throw light not only on the value of the product as a 

 food but on any possible changes occurring during the long period of storage. 



Lean, raw pork has been found to be a good source of the antineuritic factor, Bj . 

 The control samples, sent to the laboratory immediately after the slaughtering 

 of the animals contained 3.8 international units of Bj per gram for the corn 

 ration and 5.9 units for the hominy ration. After nine months of storage these 

 values remained practically unchanged (4.0 and 6.0 units respectively). 



As a source of vitamin Bg (G), lean pork seems to have much the same value 

 as lean beef, a fair source. The original samples of the pork contained 2.1 and 1.8 

 Bourquin-Sherman units per gram for the corn and hominy rations respectively. 

 After six months of storage, the samples had not changed in any significant 



