g. Legumin, as contained in peas and beans. 2. Carbohydrates, which inctude^ a. Starch, as contained in potatoes and cereals. b. Sugar; as, cane, beet, and fruit sugars. c. Cellulose, the fruit and vegetable fiber. 3. Fats, including — a. Animal fats; as, butter, lard, fat meat. b. Vegetable oils; as, olive oil, cottonseed oil. (B) Inorganic foods, or those not having animal or vegetable origin, include — 4. Mineral matter, as found in the ash of foods. 5. PFa/^r.— Water is usually not thought of as a food ; it is used in tissue building, but it does not give heat or energy. Composition and Functions of the Food Classes. — Proteins contain nitrogen, carbon, oxygen, hydrogen, sul- phur, and often phosphorus. Because they contain nitrogen, proteins build and repair tissues, and are called nitrogenous or tissue-build- ing foods. The protein of the body, as contained in the muscles, blood, and other tissues, can be built up only from the protein of food. Proteins may also be used in the body to produce heat and energy. But carbohydrates and fats, especially the former, are much cheaper as a source of heat and energy, and are much more easily used for this purpose in the body. If less pro>tein is eaten than is re- quired, the protein of the body itself will be consumed. If more protein is eaten than is needed for tissue building, the excess is thrown off as waste, the process forming 20 DOMESTIC SCIENCE Fig. 3. Food chart of comparative composition and fuel value of food materials. (U. S. D. A. Bui.) ES8ENTIAL8 TO LIFE 21 harmful products in the body and enforcing greater work on the excretory organs. Excessive consumption of pro- tein food is harmful. Carbohydrate is the general name for a large class of familiar food materials that do not contain nitrogen. In order to maintain its temperature and to do work, the body must obtain energy, and this is supplied very largely by the carbohydrates. Starches and sugars are produced in plants on a very generous scale for our use. When eaten in excess, carbohydrates are stored in the body as fatty tissue. Fats and oils are composed of the same elements as car- bohydrates; namely, carbon, hydrogen, and oxygen, and are used in the body for the same purpose. The propor- tion of carbon is much greater than in carbohydrates, for which reason they give about twice as much heat and energy. The fats, however, are harder to digest. They also add to the fatty tissue. Mineral matter, consisting of compounds of sodium, lime, iron, potash, sulphur, phosphorus, etc., are found principally in cereals, milk, meat, fish, and fruits. Min- eral substances enter into the composition of all tissues of the body, especially bone and blood, and are very neces- sary to young and growing persons. Water. (Composition and function given on page 16.) Table of Abbreviations For the sake of convenience in cookery, a few abbre- viations are used. Those used throughout this text are: tsp. for teaspoon oz. for ounce tbsp. for tablespoon f. g. for few grains ssp. for salt spoon r. for rounded c. for cup hp. for heaping pt. for pint sc. for scant qt. for quart min. for minute lb. for pound hr. for hour 22 DOMESTIC SCIENCE Table of Measures 3 tsp. are equivalent to 1 tbsp.

AI-modernized reading of the original text

g. Legumin, as contained in peas and beans. 2. Carbohydrates, which include— a. Starch, as contained in potatoes and cereals. b. Sugar; as, cane, beet, and fruit sugars. c. Cellulose, the fruit and vegetable fiber. 3. Fats, including — a. Animal fats; as, butter, lard, fat meat. b. Vegetable oils; as, olive oil, cottonseed oil. (B) Inorganic foods, or those not having animal or vegetable origin, include — 4. Mineral matter, as found in the ash of foods. 5. PFa/^r.— Water is usually not thought of as a food ; it is used in tissue building, but it does not give heat or energy. Composition and Functions of the Food Classes. — Proteins contain nitrogen, carbon, oxygen, hydrogen, sulphur, and often phosphorus. Because they contain nitrogen, proteins build and repair tissues, and are called nitrogenous or tissue-building foods. The protein of the body, as contained in the muscles, blood, and other tissues, can be built up only from the protein of food. Proteins may also be used in the body to produce heat and energy. But carbohydrates and fats, especially the former, are much cheaper as a source of heat and energy, and are much more easily used for this purpose in the body. If less pro>tein is eaten than is required, the protein of the body itself will be consumed. If more protein is eaten than is needed for tissue building, the excess is thrown off as waste, the process forming [illustration: Fig. 3. Food chart of comparative composition and fuel value of food materials. (U. S. D. A. Bui.)] harmful products in the body and enforcing greater work on the excretory organs. Excessive consumption of protein food is harmful. Carbohydrate is the general name for a large class of familiar food materials that do not contain nitrogen. In order to maintain its temperature and to do work, the body must obtain energy, and this is supplied very largely by the carbohydrates. Starches and sugars are produced in plants on a very generous scale for our use. When eaten in excess, carbohydrates are stored in the body as fatty tissue. Fats and oils are composed of the same elements as carbohydrates; namely, carbon, hydrogen, and oxygen, and are used in the body for the same purpose. The proportion of carbon is much greater than in carbohydrates, for which reason they give about twice as much heat and energy. The fats, however, are harder to digest. They also add to the fatty tissue. Mineral matter, consisting of compounds of sodium, lime, iron, potash, sulphur, phosphorus, etc., are found principally in cereals, milk, meat, fish, and fruits. Mineral substances enter into the composition of all tissues of the body, especially bone and blood, and are very necessary to young and growing persons. Water. (Composition and function given on page 16.) Table of Abbreviations For the sake of convenience in cookery, a few abbreviations are used. Those used throughout this text are: tsp. for teaspoon oz. for ounce tbsp. for tablespoon f. g. for few grains ssp. for salt spoon r. for rounded c. for cup hp. for heaping pt. for pint sc. for scant qt. for quart min. for minute lb. for pound hr. for hour Table of Measures 3 tsp. are equivalent to 1 tbsp.

Domestic science, principles and application