Human Foods and Their Nutritive Value by Harry Snyder (dark academia books to read .TXT) π
CHAPTER XXI
LABORATORY PRACTICE 299
Object of Laboratory Practice; Laboratory Note-book and Suggestions for Laboratory Practice; List of Apparatus Used; Photograph of Apparatus Used; Directions for Weighing; Directions for Measuring; Use of Microscope; Water in Flour; Water in Butter; Ash in Flour; Nitric Acid Test for Nitrogenous Organic Matter; Acidity of Lemons; Influence of Heat on Potato Starch Grains; Influence of Yeast on Starch Grains; Mechanical Composition of Potatoes; Pectose from Apples; Lemon Extract; Vanilla Extract; Testing Olive Oil for Cotton Seed Oil; Testing for Coal Tar Dyes; Determining the Per Cent of Skin in Beans; Extraction of Fat from Peanuts; Microscopic Examination of Milk; Formaldehyde in Cream or Milk; Gelatine in Cream or Milk; Testing for Oleomargarine; Testing for Watering or Skimming of Milk; Boric Acid in Meat; Microscopic Examination of Cereal Starch Grains; Identification
Read free book Β«Human Foods and Their Nutritive Value by Harry Snyder (dark academia books to read .TXT) πΒ» - read online or download for free at americanlibrarybooks.com
- Author: Harry Snyder
- Performer: -
Read book online Β«Human Foods and Their Nutritive Value by Harry Snyder (dark academia books to read .TXT) πΒ». Author - Harry Snyder
254. Dietary of Two Families Compared.βA dietary study often reveals ways in which it is possible to improve the ration in kinds and amounts of food, and sometimes at less expense. The following dietaries of two families for the same period show that one family expends over twice as much in the purchase of foods as the other family, and yet the one whose food costs the less actually secures the larger amount of nutritive material and is better fed than the family where more money is expended for food.[13]
Fig. 59.βCost and Nutritive Value of Rations.
In comparing the foods used by the two families, it will be observed that family No. 1 purchased their bread at the bakery at a cost of $ 1.00, while the bread of family No. 2 was home-made, skim milk being used in its preparation, the flour, milk, yeast, and shortening costing about 55 cents. Family No. 1 consumed 10 pounds of expensive steaks, family No. 2 consumed the same number of pounds, a portion being cheaper cuts. Instead of the 20 pounds of roast or similar beef used by family No. 1, only one half as much and cheaper cuts as boiling pieces, stew, rump roast, etc., were used by family No. 2; 5 pounds of beans and 5 pounds of cheese taking the place of some of the meat. Family No. 1 consumed 4 pounds of high-priced cereal breakfast foods, supposing they contained a larger amount of nutrients than were actually present. In place of the 4 pounds of high-priced cereal breakfast foods of family No. 1, family No. 2 used 5 pounds of oatmeal purchased in bulk. Family No. 1 bought their cake and pastry for $3.00, while those of family No. 2 were home made and cost $1.00. Family No. 2 used 2 pounds less butter per week because of the preparation and use of home-made shortening from beef suet and milk. They also purchased a smaller amount of tea, coffee, and spices than family No. 1. Family No. 2 consumed a larger quantity of less expensive fruits and vegetables than family No. 1, who ate 75 cents' worth of mushrooms with the idea that they contained as much protein as meat, but analyses show that mushrooms contain no more nutrients than potatoes and similar vegetables. In place of the celery and oranges, apples and prunes were used by family No. 2. The same amount of potatoes was used by each. Fifty cents was spent for milk by family No. 1 and $1.00 by family No. 2. The total amount expended for food by family No. 1 was $23.45, while family No. 2 purchased a greater variety of foods for $11.30, as well as foods containing more nutrients. The approximate amounts of nutrients in the foods purchased by the two families are given in the following table, from which it will be observed that family No. 2 obtained a much larger amount of total nutrients and was better fed at considerably less expense than family No. 1.
drates Lb. Lb. Lb. 20 lb. bread 1.98 0.28 11.42 10 lb. loin steak 1.59 1.76 β 20 lb. rib roast 2.68 4.26 β 4 lb. cereals 0.42 0.06 2.75 8 lb. butter 0.04 6.80 β 25 lb. potatoes 0.45 0.03 3.83 20 lb. milk 0.70 0.80 1.00 ββ ββ ββ 7.86 13.99 19.00
drates Lb. Lb. Lb. 15 lb. flour 1.89 0.12 11.15 5 lb. skim milk 0.16 0.01 0.26 10 lb. round steak 1.81 1.26 β 10 lb. beef 1.32 2.02 β 5 lb. cheese 1.40 1.75 β 5 lb. oatmeal 0.78 0.36 3.40 6 lb. butter 0.03 5.10 β 3 lb. shortening β 2.55 β 3 lb. prunes 0.03 β 0.60 25 lb. apples 0.12 β 2.50 25 lb. potatoes 0.45 0.03 3.83 40 lb. milk 1.44 1.60 1.90 5 lb. beans 1.12 β 3.00 ββ ββ ββ 10.55 14.80 26.64 Difference in nutrients in favor
of family No. 2, consuming the
cheaper combination of foods 2.69 0.81 7.64
255. Food in its Relation to Mental and Physical Vigor.βWhen the body is not properly supplied with food, the best results in the form of productive work cannot be secured. There is a close relationship between the nature of the food consumed and mental activity, also ability to satisfactorily perform physical labor. "The productive power of the individual as well as of the nation depends doubtless upon many factors other than food, such as race, climate, habit, etc., but there is no gainsaying the fact that diet has also a profound and direct influence upon it."[83]
If the body is diseased, it cannot make the right uses of the food, and often the food is blamed when the trouble is due primarily to other causes. The fact that a diseased digestive tract is unable to utilize some foods is no valid reason why these foods should be discarded in the dietary of persons in normal health, particularly when the food is in no way responsible for the disease.
Some diseases are most prevalent in the case of a restricted diet. A change in the dietary of the Japanese navy greatly improved the health of the sailors.
"The prevalence of kakke or beriberi in the navy turned the attention of many medical specialists toward the problem of nutrition.... It was generally believed that there was some very close connection between the disease and the rice diet.... One outcome of these investigations was the passage of the food supply act of the navy in 1884. The ration provided in accordance with this act was sufficient to furnish an abundance of protein and energy.... Following the change of ration in 1884, the prevalence of the disease was very materially diminished, and at the end of three years cases of kakke were practically unknown among the marines."[83]
256. Dietary Studies in Public Institutions.βDietary studies in public institutions, as prisons, and asylums for the insane, show that it is possible to secure greater variety of food containing a larger amount of nutrients, and even at a reduction in cost.[84] In such institutions it is important that the food should be not only ample in amount, but wholesome and nutritious, as many of the inmates respond both physically and mentally to an improved diet. For humanitarian as well as economic reasons institutional dietetics should more generally be placed under the supervision of skilled dietists.
CHAPTER XVIII RATIONAL FEEDING OF MAN257. Object.βRational feeding of man has for its object the regulation of the food supply in accord with the demands of the body. It is based upon the same principles as the rational feeding of animals; in each, the best results in the way of health, amount of labor performed, and economy are secured when the body receives nutrients sufficient for the production of heat and energy and for the repair of worn-out tissues. Rational feeding is simply regulation of the food, both as to kind and amount, to meet the needs of the body.[72]
258. Standard Rations.βIn human feeding, as in animal feeding, it is not possible to lay down hard and fast rules as to the quantity of nutrients required for a standard ration.[85] As stated in the chapter on Dietary Studies, such standards have been proposed, but they are to be considered as tentative rather than absolute, for the amount of food required by different persons must necessarily vary with the individuality. While it is impossible to establish absolute standards, any large variation from the provisional standards usually results in lessened ability to accomplish work, ill health, or increased expense.
259. Amounts of Food Consumed.βThe approximate amounts of some food articles consumed per day are as follows:
Amount in Lbs. Bread 6 to 14 oz. 0.50 Butter 2 to 5 oz. 0.12 Potatoes 8 to 16 oz. 0.75 Cheese 1 to 4 oz. 0.12 Beans 1 to 4 oz. 0.12 Milk 8 to 32 oz. β Sugar 2 to 5 oz. 0.20 Meats 4 to 12 oz. 0.25 Oatmeal 1 to 4 oz. 0.12
In the calculation of rations it is desirable that the amount of any food article should not exceed that designated, unless for some special reason it has been found the food can consistently be increased. The amount of nutrients given in dietary standards is for one day, and the nutrients may be divided among the three meals as desired. It is to be noted that, ordinarily, the foods which supply carbohydrates are flour, corn meal, cereal products, potatoes, beans, sugar, and milk; those which supply fat are milk, butter, lard, and meats; and those which supply protein in liberal amounts are beans, cheese, meats, oatmeal, cereals, bread, and milk.
260. Average Composition of Foods.βThe amounts of nutrients in foods are determined from the average composition of the foods. These figures for average composition are based upon analyses of a large number of samples of food materials.[7] In individual cases it will be found that foods may vary from the standards given; as for example, milk may contain from 2.5 to 5 per cent of fat, while the protein and fat of meats vary appreciably from the figures given for average composition. With the cereals and vegetable foods, variations from the standards are small. In the table, the composition of the food as purchased represents all of the nutrients in the food, including those in the refuse, trimmings, or waste, while the figures for the edible portion represent the nutrients in the food after deducting what is lost as refuse. In making calculations, the student should use the figures given for the foods as purchased, unless the weights are of the edible portion only. The figures in the table are on the basis of percentage amounts, or nutrients in 100 pounds of food. By moving the decimal point two places to the left, the figures
Comments (0)