Principles of cooking

U.S. Department of Agriculture Prepared by Office of Experiment Stations C, F, LANGWORTHY A.C. True: Director Expert in Charge of Nutrition Investigations COMPOSITION OF FOOD MATERIALS. TTT RRO WY. BSA ; Fuel Value est Se Ao $q.1n.E qual p As W eas ies, rotein Fat Carbohydrates h ater 1000 Calories SHELLED BEAN, FRESH NAVY BEAN, DRY. Water:58.9 ; ; Protein: 22, Carbohydrates:29. | Saget ae -Fueu vatue: Fuet vavue: 720 CALORIES PER POUND 1560 catories PER POUND STRING BEAN, GREEN. Water:89.2 Fuet vavue: [90 cacories PER POUND CORN, GREEN. EDIBLE PORTION Water: 75.4 Ot POAT) NTT TT) COMPOSITION OF VEGETABLES. ¢ PRINCIPLES OF COOKING U. $. Department of Agriculture Prepared by Office of Experiment Stations . C. F, LANGWORTHY A. C, True: Director Expert in Charge of Nutrition Investigations COMPOSITION OF FOOD MATERIALS. See Fuel Value eS X%6Sq.ln.Equals Protei Carbohydrates Ash Water 1000 catenes ONION a A Ges Fea Water:87.6 LA crac n Be PD Fuel VALUE: 220 caLories PER POUND FueL VALue: 2905 CALORIES PER POUND (| Reed it PARSNIP FaBY' Y) 72s (\ eae are? Wi te L) Dy) SERIE SUT POTATO Protein:2.2 a % it Water:94.5 ; \ BF dae : Cee My i Carbohydrates: 18.4 Water: 78.3. FUEL VALUE: L_| ] 80 CALORIES 375 calories PER POUND PER POUND UU Fuel VALUE: Protein:!.| COMPOSITION OF VEGETABLES. & oF 38 PRINCIPLES OF COOKING STATEMENT OF PRINCIPLES. \ 1. Heat and moisture soften walls of cellulose in vege- | table foods; the denser the walls, the longer time it takes to soften them. | 2. Heat and moisture cause starch grains to swell and — ‘burst the walls of cellulose that inclose them, and gelatinize or cook the starch. Recipe for Baked Apples.— Wash and wipe apples and remove core. Place in a granite pan with one table- spoon of sugar in each apple and add water enough to just cover the bottom of the pan. Bake in a hot oven, about 30 to 45 minutes. Apples containing a great deal of acid cook much more quickly than those that are not so tart. Calculate cost. When would you serve baked apples? Ait what meal? Vegetables differ in the amount of nourishment which they contain. They all contain carbohydrate in some form, though the amount and kind varies. Potatoes, wheat, corn, oats, rice, peas, and beans contain consider- able starch. The carbohydrate in other vegetables and fruits is small in quantity, and consists of sugar, pectin, cellulose, and some starch. All vegetables contain mineral salts; fruits contain vegetable acids also. Some vege- — tables and fruits contain oil, called a volatile oil, because it can be turned to vapor and carried off in steam. All vegetables contain some protein. Apples contain : — Water Protein Fat Carbohydrate Cellulose! Mineral Matter 84.076 3 Ao 570 9. 1h 2% 12% 3% PRINCIPLES OF COOKING 39 The carbohydrate is in the form of sugar, pectin, and cellulose. Apples also contain a vegetable acid. Some varieties contain more cellulose than potatoes and hence it takes a longer time to cook them. Some varieties con- tain much more acid than others, and as the acid helps soften the cellulose, those containing the greatest amount of acid bake quickest. As apples contain practically no starch, cooking is not necessary, but cooking softens the cellulose and makes it possible to serve apples in a great variety of ways. As apples ripen the sugar content in- © creases, the cellulose becomes less tough, and the acidity decreases. For general use the ripe apple is preferred. STATEMENT OF PRINCIPLES INVOLVED. 1. Moist heat softens the walls of cellulose in vegetable foods; the denser the walls the longer time it takes to soften them. 2. Acids soften cellulose. 3. Heat melts sugar.