FOOD VALUE OF SEA MUSSELS. 
IOI 
discomfort. One man with whom meat dqes 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. 
Protein in 
filtrate. 
Protein in 
residue. 
Per cent dis- 
solved. 
For two hours’ digestion: 
Grams. 
Gram. 
Mussels 
0. 5783 
0. 201 2 
74 - 1 
Beef 
1 . 1656 
■ 2705 
81 . 1 
For four hours’ digestion: 
Mussels 
. 6107 
. 1522 
80. 0 
■ 7455 
. 2104 
77 - 9 
1. 2930 
• 1450 
96. 7 
