1916] FOODS HUMAN NUTRITION. 267 



[Food and dinig anlyses], E. P. Ladd and Axma K. Johnson (North Dakota 

 Sta., Spec. Bui., 4 (1916), No. 3, pp. 72-80).— This part of the bulletin contains 

 a report on prepared mustard by R. E. Remington, which includes analytical 

 data. Information is also given regarding some proprietary medicines ex- 

 amined, and the results are reported of the analysis of several samples of foods 

 and beverages. 



The economics of electric cooking, P. W. Gumaer (Univ. Missouri Bui., 16 

 (1915), No. 21, pp. 62, figs. 37).— The object of the investigation here reported 

 was to ascertain some of the factors which increase the economy of electric 

 cooking. Tests were made with three commercial and several especially con- 

 structed experimental ovens, in order to determine the amount of energy con- 

 sumed in cooking, and the best methods of prepnring different foods for the elec- 

 tric oven. The details of construction of the ovens are described in the bulletin, 

 as are also the method of measuring by means of copper-constantan thermo- 

 couples, the temperatures of the ovens and the internal temperature of the foods 

 during cooking. The experiments furnished considerable information as to the 

 losses of energy in electric ovens due to convectioH and radiation, preheating, and 

 the opening of the oven door. 



" The energy lost when the door of an electric oven is opened for 15 seconds 

 was determined for various oven temperatures. For an oven temperature of 

 200° C. (392° P.) used in baking bread, biscuits, etc., the loss due to opening a 

 12-inch by 18-inch oven door for 15 seconds amounted to 12 watt hours. At 

 5 cts. per kilowatt hour for electric current this would mean a cost of 0.06 ct. 

 each time the door was opened for a period of 15 seconds. 



" Since the purpose of cooking food is not to put as many heat units as 

 possible into the food, but is rather to improve its flavor, and to increase its 

 digestibility, the steam boiler method of determining efficiency is not applicable 

 to electric ovens." 



Considerable space is devoted to a discussion of the general efficiency of 

 electric ovens. " In order to compare the cost of cooking in various electric 

 ovens, a method proposed for indicating the relative efficiency of the electric 

 ovens is to specify the amount of the preheating and the radiation losses at 

 the required oven temperatures." 



Experiments were undertaken to determine the most satisfactory and eco- 

 nomical temperatures for roasting beef. Twenty-two rib roasts of like size 

 and quality were boned, rolled, and roasted at 100, 120, 140, 160, and 180° C, 

 the time required for the cooking, the loss in weight, and the amount of 

 energy consumed at each temperature being measured. To secure uniform 

 results in the degree to which the meat was cooked, each piece was removed 

 from the oven when the interior reached a definite temperature. An inner 

 temperature of 55° was taken to indicate meat that was rare, 65° medium 

 rare, and 75° well-done meat, since these figures conformed to the usage of 

 other experimenters. A table is given which shows the temperatures of the 

 roasts on removal from the oven which gave the most satisfactory results as 

 regards quality of the meat. The searing of the meat previous to roasting was 

 accomplished in an open aluminium dish over a heating coil, this method being 

 found to result in a saving of 5 cts., on the basis of 5 cts. per kilowatt hour 

 for electric current, over the method of heating the whole oven up to 250° for 

 10 to 15 minutes in order to sear the outside of the meat. 



Figures are given which show the time temperature curves for the inside 

 of the roasts for different oven temperatures, which are of especial interest 

 in cooking studies. " The shortest time of roasting was at 160°. 



" The percentage loss of weight of the roasts was found to increase with the 

 oven temperature used." 



