The food value of sea mussels / by Irving A. Field.

  • Field, Irving Angell, 1870-1921.
Date:
1911
Catalogue details

Licence: In copyright

Credit: The food value of sea mussels / by Irving A. Field. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    discomfort. One man with whom meat does not ordinarily agree states that he can eat freely of mussels and digest them without difficulty. Many persons have declared that in their opinion mussels are more digestible than either clams or oysters, a fact due to the character and properties of the flesh which by cooking is rendered tender and mealy, whereas the oyster and clam become very tough. But the problem of really determining the digestibility of a given food material is surrounded with great difficulties. It is an easy matter for one to eat the food and learn by experience how it agrees or disagrees with him; but to determine the rate of diges- tion and the proportion of nutriment which the body absorbs from a given quantity of the food involves a series of very complex chemical studies. EXPERIMENTS TO SHOW AVAILABLE PROTEIN. By artificial methods it is possible, however, to determine approximately the pro- portion of protein which is rendered soluble and absorbed by the animal body. Diges- tion experiments of this sort were made by Dr. C. L. Alsberg. His method and results are as follows: Mussels, hard-boiled eggs (yolk and white together), and thoroughly boiled beef were each ground up in an ordinary kitchen sausage machine. Each chopped-up sample was thoroughly mixed to make it as uniform as possible. Then 5-gram samples were weighed out. Each sample was placed in a flask containing 100 c. c. of artificial gastric juice. This juice was prepared by dissolving 0.5 gram pepsin in 1 liter 0.15 per cent hydrochloric acid. All the flasks were placed in a thermostat at a temperature of 38° C. At stated intervals they were all shaken by hand. After two hours one-half the flasks were removed from the thermostat. The remainder were removed after four hours. Imme- diately after taking them out of the thermostat each flask was brought to a boil in order to destroy the enzymes. Each was then filtered through an ash-free quantitative filter, and when all the liquid had passed through the filter the undissolved residue was washed with 100 c. c. of distilled water. When all the wash water had passed through the filter, the amount of nitrogen was determined by the Kjeldahl method in the combined filtrate and wash water as well as in the undissolved residue. From the relative amounts of nitrogen in the filtrate and undissolved residue an opinion may be formed as to how much protein has been rendered soluble by the action of the gastric juice. This method is not accurate, but it is believed to be more accurate than the methods commonly employed, in which the various digestion products are precipitated out and weighed. The washing and drying of such proteins upon filters presents great difficulties. It is believed that the determination of the nitrogen rendered soluble gives a better index of the effect of the digestion. The figures obtained were multiplied by 6.25 to indicate the amount of protein corresponding to them. The resulting figures are given in the following table, each figure representing the average of several experiments: Table i.—Results of Experiments to show Available Protein in Mussels. Substance. For two hours’ digestion: Mussels Egg Beef For four hours’ digestion: Mussels Egg Beef Protein in filtrate. Protein in residue. Per cent dis- solved. Grams. Gram. 0.5783 0. 2012 74- 1 .6168 . 1866 76.0 1.1656 . 2705 81. 1 . 6107 . 1522 80. 0 • 74SS . 2104 77- 9 I.2930 • 1450 96.7