Q2 STORRS AGRICULTURAL EXPERIMENT STATION. 
TABLE ‘6! 
Average determined heat of combustion of proteids and non-pro- 
teids and calculated heat of combustion of protein. 


HEAT OF COMBUSTION 




PER GRAM. 
KIND OF MATERIAL. 
; Assumed 
Determined: | or calculated. 
J Calories... | Calories, 
Beef, fat-free muscle, - “ 35 - s 5.65 — 
Beef, fat-free muscle, extractives removed, - Ck —— 
Veal, fat-free muscle, us te bal ud i a 5.65 : == 
Mutton, fat-free muscle, - - - - - 5.60 — 
Protein of meat, - - 4 é - ‘ — 5.05 
Egg albumin, - - - - - : - 595 — 
Egg, protein of yolk, - - : - s 5.84 — 
Vitellin, - 2 = eh s = Z 3 5.76 ate 
Protein of egg, - - - ih ae ay ieee 5.76 
Milk casein, - ~ z - - “ - 5.63 to 5.86 — 
Milk protein, - rat car 2 - “ 2 5.67 ~ 
Protein of dairy products, te ‘ : z mes | 5.65: 
Ghadin. == - 2 = a fe 2 5.92 a 
Glutenin, - - - - : - = - 5.88 hans 
Gluten of wheat, ~ “ é - 2 < 5.95 | Seas 
Legumin, - - : - - : ¢ B70 Foes 
Plant fibrin, Mpa acne = = - é £ 5.89 ps 
Protein of cereals (96 % proteids), = 5 ‘ = 5.80 
Protein of legumes (96 % proteids),  - 3 - — | 5. 7o 
Protein of vegetables (60 % proteids), ; — 5.00 
Protein of fruits (70 % proteids), i - : a 5.20 
Gelatin, é - 3 z z Z ce oF oa 
Creatin, as type of non-proteids of animal foods, 4.27 — 
Asparagin, as type of non-proteids of vegetable 4 
foods, - ~ = = 2. = = 3.45 — 


HEAT OF COMBUSTION OF FATS OF DIFFERENT FOOD MATERIALS. | 
In determining the amount of fat in a food material the sub- 
stance is commonly extracted with ether. The ether extract, 
_ however, is apt to contain more or less material not actually — 
fat and with a lower calorific value. On the other hand, with 
some food materials, ¢. ., meats, with a large proportion of 
fat, the extraction by ether is sometimes incomplete, so that 
the fat obtained is less than the actual amount in the material. 
The heat of combustion of the pure fats (triglycerids) of 
ordinary meats has been found to vary little from 9.5 calories 
per gram, while that of butter-fat averages not far from O725— 
calories per gram, and that of the fats and oils of ordinary veg- 
etable foods about 9.3 calories per gram. ‘The values for the 

