Composition of Caviar.—
| Water, | 66.05 | percent |
| Protein, | 14.37 | „ |
| Fat, | 8.97 | „ |
| Ash, | 7.26 | „ |
| Undetermined, | 3.35 | „ |
Of the ash, 6.16 parts of the 7.26 present are common salt.
Composition of the Eggs of Fish.
—Attention has been called to the valuable food properties of the eggs of fishes. The roe of a number of fishes is celebrated both for flavor and food value. The two most important roes are those of the sturgeon, used in the manufacture of caviar, and the roe of shad, used principally in the fresh state.
Composition of Roe.
—The composition of shad roe, fresh sturgeon caviar, and pickled caviar is given in the following table:
| Water. | Protein. | Fat. | Ash. | |
|---|---|---|---|---|
| Percent | Percent | Percent | Percent | |
| Shad roe, | 71.25 | 23.44 | 3.78 | 1.53 |
| Fresh caviar, | 56.97 | 27.87 | 2.85 | 2.31 |
| Pickled caviar, | 50.92 | 27.92 | 13.59 | 7.57 |
The above data show a marked difference between the composition of shad roe and sturgeon roe, the latter being very much richer in fat and also containing a greater quantity of ash. The large quantity of ash in the pickled caviar is doubtless due to the common salt used in the curing. There is not a very great difference between the composition of the roe and that of the flesh of fish. The roe is essentially a nitrogenous food, also with a considerable quantity of fat and with a certain amount of mineral matter. It contains less water than the flesh of fish, and, therefore, pound for pound in the fresh state has a larger quantity of nutrients. Otherwise, for food purposes, there is but little difference. It is doubtless true, however, that the mineral matters of the roe are somewhat different from those of the flesh of fish in containing a larger quantity of organic phosphorus in the form of lecithin.