THE DIGESTION OF PROTEIN.—It was mentioned previously that proteins are made up of many different substances. The materials composing proteins are called amino acids. There are 18 common amino acids. All proteins are not made up of the same amino acids. Amino acids in the various proteins differ not only in kind, but in quantity.

When proteins are digested, they undergo certain changes and are finally separated into their amino acids. As amino acids proteins are finally absorbed and carried to all parts of the body.

The digestion of protein begins in the stomach and continues in the intestines. The digestive juices [Footnote 47: The pepsin and hydrochloric acid of the stomach, the trypsin of the pancreatic juice, and the erepsin of the intestinal juice digest proteins.] of these organs change protein into soluble forms.

POACHED EGG

Fill a shallow pan about two thirds full of boiling water. Add 1/2 teaspoonful of salt to each pint of water; place buttered muffin rings in the pan. Break separately each egg into a saucer and carefully slip it into a buttered muffin ring. Cover the pan and place it where the water will keep hot but not boil. Pour a spoonful of the hot water on each yolk occasionally.

Let stand (about 5 minutes) until the white is coagulated and a film covers the yolk. Take up with a skimmer, drain, place on slices of toast, and serve at once.

An egg poacher may be used in place of the muffin rings, or the water in the pan may be stirred in a circular motion and the eggs dropped at once into the "whirlpool." This tends to keep the white of egg from separating into pieces.

Eggs are thought by some to be much more tasty when poached in milk rather than in water.

GOLDENROD EGGS

3 or 4 hard-cooked eggs 2 tablespoonfuls flour 1/8 teaspoonful pepper 3/4 teaspoonful salt 1 1/2 tablespoonfuls butter or substitute 1 1/2 cupfuls milk 6 pieces of toast Parsley

Separate the yolk and white of the cooked eggs and chop the whites. Make a White Sauce of flour, seasoning, fat, and milk. Add the chopped egg whites to the sauce and pour it over the toast. Press the yolks through a strainer or crush them with a fork and sprinkle them over the top of the toast. Garnish with parsley and serve at once.

If the crusts are not cut from bread in making toast, it is well to dip the edges of each slice of toast for an instant in hot, salted water before adding the sauce (see Cream Toast).

QUESTIONS

Why is it advisable to pour occasionally a spoonful of hot water over the yolks of eggs that are being poached?

Explain why the chopped hard-cooked eggs in Goldenrod Eggs should be more easily digested than plain hard-cooked eggs (see Experiment 12, and Solution and Digestion).