13 



nutrients than the other foods, and, so far as we may judge from their 

 mere chemical composition, are not superior in value. Taking all the 

 facts into consideration, we would naturally be led to conclude that, as 

 the oat products contain the most protein, or muscle-forming material, 

 and the largest percentage of fat, they are the most nutritious foods. It 

 is also evident that these foods are also superior to all others as heat 

 producers. 



Influence of Special Process of Manufacture on Solubility of Foods. 



The composition, as given above, does not show the changes that 

 cooking, parching and malting processes have effected in the ready-to- 

 serve foods, and, as it is because of these changes that so much is claimed 

 for them, we studied this point somewhat fully. The object of treating 

 these foods with malt is to increase the solubility, and, consequently, the 

 ease of digestion of the starch. As previously explained, the diastase of 

 malt converts starch into dextrin and maltose, — water-soluble compounds. 

 Cooking in water, or by dry heat, as in toasting or parching, also tends 

 to break down starch into simpler substances which are soluble in water. 

 If, then, we determine the amount of a food that will dissolve in water, 

 we must, to some extent, measure the efficiency of the malting and cook- 

 ing processes used in the preparation of that food. In order that we might 

 procure some data on this point, we determined the amount of the total 

 solids soluble in water in some uncooked, partially cooked, cooked, and 

 cooked and malted foods. We also analyzed the water extract to ascer- 

 tain how far the decomposition process had proceeded. 



The methods used in making the extractions and determinations 

 were based on those outlined by A. McGill in Bulletin No. 84, Inland 

 Revenue Department, Ottawa. Briefly, the methods were as follows . 

 100 grams of the material in its natural condition and 1,000 cc. of dis- 

 tilled water at room temperature were placed in a 2-litre bottle, and fas- 

 tened on a rotating machine which turned the bottles end over end at the 

 rate of 40 revolutions per minute for 24 hours. Previous experimental 

 work demonstrated that up to this length of time there was a sensible 

 increase in the amount of material brought into solution. The contents 

 of the bottle were then placed in a cup of 300 cc. capacity in a large 

 centrifuge and whirled at the rate of 2,000 revolutions per minute for one 

 hour, or until the insoluble matter was thrown down. After filtering 

 through close paper, to insure a clear solution, the per cent, of solids, 

 dextrin, sugar, and proteids were determined. The dextrin was estimated 

 by evaporating a portion of the clear filtrate nearly to dryness, and after- 

 wards taking up with alcohol, filtering off, drying, and weighing the 

 resulting precipitate. As such a precipitate would not be pure dextrin, 

 it is reported simply as "alcohol precipitate." The sugar was determined 

 in the usual way with Fehling's solution, and, as no effort was made to 

 separate the probable sugars present, it was reported as "cuprous oxide 

 precipitate." Approximately, 1 per cent, of cuprous oxide is equal to 



