Losses in boiling vegetables and the composition and digestibility of potatoes and eggs / by H. Snyder, Almah J. Frisby, and A.P. Bryant.

  • Snyder, Harry, 1867-1927.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: Losses in boiling vegetables and the composition and digestibility of potatoes and eggs / by H. Snyder, Almah J. Frisby, and A.P. Bryant. Source: Wellcome Collection.

    23/34 (page 21)
    500 parts of water. This solution dissolved 50 parts of liard-boiled egg albumen in six and one-half hours at a temperature of from 38° to 40o O. Eggs were cooked for 3 minutes at 100° C., giving a u soft-boiled v egg, and for 5 minutes and 20 minutes at the same temperature. One egg boiled 3 minutes and digested for 5 hours in about 200 cc. of pepsin solution as prepared above, compared with one boiled 20 minutes and treated in the same way, showed 8.3 per cent undigested nitrogen in the former, against 4.1 per cent undigested nitrogen in the latter. Under similar treatment the egg boiled 5 minutes gave 3.9 per cent undigested nitrogen. Another trial was then made, in which the eggs were cooked for periods of 5 and 10 minutes in water at 82.2° 0. (180° F.) In both of these cases the nitrogen was entirely digested in 5 hours. The results are given in the following table: Result of digesting boiled eggs 5 hours in pepsin solution. X o. of experi¬ ment. Length of time cooked. Tempera¬ ture at which cooked. Weight egg used (without shell). Total nitrogen in fresh eggs. Total undi¬ gested nitrogen. Total nitrogen digested. Pepsin solution used. Minutes. Deg. F. Grains. Grams. Grams. Per cent. Cc. 1 5 180 39. 34 .944 100.0 197 2 10 180 47. 02 1.128 100.0 235 3 3 212 38. 67 .929 0.0768 91.7 193 4 5 212 43. 80 1.050 .0408 96.1 219 5 20 212 40. 64 .960 .0408 95.8 203 From the above it seems probable that while the method of cooking has some elfect upon the rate of digestibility it does not materially affect the total digestibility. These results agree quite closely with those obtained by Rubner.1 In an experiment with man he found that 97.1 per cent of the nitrogen of hard-boiled eggs was digested. DIGESTION EXPERIMENT ON MAN WITH A DIET OF POTATOES, EGGS, MILK, AND CREAM. The subject of the digestion experiment was a healthy man, 22 years old. He was a laboratory assistant, and his work did not demand a great amount of muscular exercise. The experiment began with dinner May 14, 1896, and ended after dinner May 18, covering 13 meals, or 4J days. The weight of the subject (without clothing) at the beginning of the experiment was 62.5 kilograms (137J pounds) and at the end 62.6 kilograms (137f pounds). The daily dietary as finally adopted consisted of 1587.6 grams (3J pounds) of potatoes, 8 eggs, 710 cubic centimeters (1£ pints) of milk, and 237 cubic centimeters (Jpint) of cream. The latter was necessary in order to supply fat to raise the fuel value of the food to the desired 1 Ztschr. Biol., 1879, p. 128. U. S. Dept. Agr., Office of Experiment Stations Bui. 21, p. 61.