13. What does heat do to the foodstuffs ? Protein. There are several forms of protein, with differences that we can understand only after a thorough study of chemistry. 300 FOOD AND HEALTH The most important proteins in meat, fish, eggs, milk, old beans, and peas coagulate, or become slightly harder or firmer at a tem- perature below the boiling point of water. There is no marked chemical change; that is, the protein is not changed to another isubstance. Fats. Solid fats are liquefied by heat, and freed from the tissue that contains them in animal fats like suet. When a fat begins to smoke with heat, a chemical change is taking place. If intense heat is continued, all the hydrogen and oxygen are driven off and pure carbon remains. When the fat is " brown," giving the flavor we like, a part of the oxygen and hydro- gen have been driven off. The " boiling " of fat in a kettle is ordinarily due to the boiling of the water contained in the fat. Starch. Starch occurs in the form of granules. See Fig. 56. In boiling water, the granule expands and finally bursts, and frees the content, the pure starch, and the whole mass thickens. Boiled with an acid the starch is changed to dextrin, a substance resembling a gum, and the mixture becomes thin ; and this process continued changes the dextrin to dextrose. With intense " dry " heat, as in toasting, the granule expands and opens, and the contents change to dextrin. Continued heat reduces the starch to pure carbon. The brown color and pleasant flavor in toast are a stage on the road to carbon. Sugar. Sugar first melts with heat, then begins to decompose, giving off water. This is also a stage on the road to pure carbon. Caramel, a familiar flavor, is sugar in the brown stage, with the water partly driven off. The art in applying intense heat to fat, starch, and sugar is to know the stopping point, — to reach the " brown taste " and stop short of the " burnt taste." Mineral matter. The " ash " remains for the most part un- changed by heat, but may be lost in the water in which vegetables and meat are cooked if the water is thrown away. Vegetable fiber is softened by heat and moisture, and the pro- MARJORIE ALLEN'S NOTEBOOK 301 tein, starch, fat, and sugar are freed, making them available for our digestion and nutrition. Meat fiber softens at a low temperature, that is, below the .boiling point of water, with moisture; continued intense heat shrinks and hardens it. A tender steak fried with fat in a hot pan will soon resemble sole leather. 14. Suggestions for the basket lunch. I copied this from Farmers' Bulletin No. 712, by Miss Caroline L. Hunt : Paper napkins or paper towels of much the same size are very useful for packing lunches, and, like paraffin and parchment paper, may now be bought at a low price. Napkins can be made also out of cotton crepe at a cost of a very -few cents each. The crepe may be bought by the yard, and should be cut into squares and fringed. Such napkins do not need to be ironed. In packing the lunch basket put at the bottom the things least likely to crush, and wrap the sandwiches, etc., into neat parcels, not all in one. Paper cups; jelly tumblers with covers, which can now be bought in several sizes; bottles with screw tops, such as those in which candy and some other foods are sold; and small jars such as those in which some goods are sold by druggists, can all be used for packing jellies, jams, and honey, and other foods. A Few Bills of Fare for the Basket Lunch 1. Sandwiches with sliced tender meat for filling; baked apple, cookies, or a few lumps of sugar. 2. Slices ofmeat loaf or bean loaf; bread and butter sandwiches ; stewed fruit; small frosted cake. 3. Crisp rolls, hollowed out and filled with chopped meat or fish, moistened and seasoned, or mixed with salad dressing ; orange, apple, a mixture of sliced fruits, or berries ; cake.

AI-modernized reading of the original text

13. What does heat do to the foodstuffs ? Protein. There are several forms of protein, with differences that we can understand only after a thorough study of chemistry. The most important proteins in meat, fish, eggs, milk, old beans, and peas coagulate, or become slightly harder or firmer at a temperature below the boiling point of water. There is no marked chemical change; that is, the protein is not changed to another substance. Fats. Solid fats are liquefied by heat, and freed from the tissue that contains them in animal fats like suet. When a fat begins to smoke with heat, a chemical change is taking place. If intense heat is continued, all the hydrogen and oxygen are driven off and pure carbon remains. When the fat is " brown," giving the flavor we like, a part of the oxygen and hydrogen have been driven off. The " boiling " of fat in a kettle is ordinarily due to the boiling of the water contained in the fat. Starch. Starch occurs in the form of granules. See Fig. 56. In boiling water, the granule expands and finally bursts, and frees the content, the pure starch, and the whole mass thickens. Boiled with an acid the starch is changed to dextrin, a substance resembling a gum, and the mixture becomes thin ; and this process continued changes the dextrin to dextrose. With intense " dry " heat, as in toasting, the granule expands and opens, and the contents change to dextrin. Continued heat reduces the starch to pure carbon. The brown color and pleasant flavor in toast are a stage on the road to carbon. Sugar. Sugar first melts with heat, then begins to decompose, giving off water. This is also a stage on the road to pure carbon. Caramel, a familiar flavor, is sugar in the brown stage, with the water partly driven off. The art in applying intense heat to fat, starch, and sugar is to know the stopping point, — to reach the " brown taste " and stop short of the " burnt taste." Mineral matter. The " ash " remains for the most part unchanged by heat, but may be lost in the water in which vegetables and meat are cooked if the water is thrown away. Vegetable fiber is softened by heat and moisture, and the pro- tein, starch, fat, and sugar are freed, making them available for our digestion and nutrition. Meat fiber softens at a low temperature, that is, below the .boiling point of water, with moisture; continued intense heat shrinks and hardens it. A tender steak fried with fat in a hot pan will soon resemble sole leather. 14. Suggestions for the basket lunch. I copied this from Farmers' Bulletin No. 712, by Miss Caroline L. Hunt : Paper napkins or paper towels of much the same size are very useful for packing lunches, and, like paraffin and parchment paper, may now be bought at a low price. Napkins can be made also out of cotton crepe at a cost of a very -few cents each. The crepe may be bought by the yard, and should be cut into squares and fringed. Such napkins do not need to be ironed. In packing the lunch basket put at the bottom the things least likely to crush, and wrap the sandwiches, etc., into neat parcels, not all in one. Paper cups; jelly tumblers with covers, which can now be bought in several sizes; bottles with screw tops, such as those in which candy and some other foods are sold; and small jars such as those in which some goods are sold by druggists, can all be used for packing jellies, jams, and honey, and other foods. A Few Bills of Fare for the Basket Lunch 1. Sandwiches with sliced tender meat for filling; baked apple, cookies, or a few lumps of sugar. 2. Slices ofmeat loaf or bean loaf; bread and butter sandwiches ; stewed fruit; small frosted cake. 3. Crisp rolls, hollowed out and filled with chopped meat or fish, moistened and seasoned, or mixed with salad dressing ; orange, apple, a mixture of sliced fruits, or berries ; cake.

Food and health