Human Foods and Their Nutritive Value Part 24

685. How is it possible to determine approximately which of two foods is cheaper, when the price and composition of the foods are known? 686. To what nutrient is preference usually given in a.s.signing a value to a food? 687. When the difference in this nutrient between two foods is small, then the preference is given to what nutrients? 688. At ordinary prices, what are the cheapest vegetable foods? 689. What are among the cheapest animal foods? 690. Why is it not possible to determine the value of a food absolutely from its composition and digestibility? 691.

Why is it necessary to consider the physical as well as the chemical composition of foods? 692. What proportion of the income of the laboring man is usually expended for food? 693. What are the most expensive foods? 694. What foods furnish the largest amount of nutrients at the least cost?

CHAPTER XVII

DIETARY STUDIES

695. What is a dietary study? 696. How is a dietary study made? 697.

What is the value of the dietary study of a family? 698. To what extent does the protein in the dietary range? 699. Why is a scant amount of protein in a ration undesirable? 700. Why is an excess of protein in the ration undesirable? 701. What are dietary standards? 702. How are such standards obtained? 703. Why is it desirable in a ration to secure the protein and other nutrients from a variety rather than from a few foods?

704. Why is it necessary to consider the caloric value of a ration? 705.

How is this determined? 706. What is a wide nutritive ratio? 707. What is a narrow nutritive ratio? 708. Why should the amount of nutrients consumed vary with the work performed? 709. How should the nutrients be apportioned among the meals? 710. What are some of the most common dietary errors? 711. What a.n.a.logy exists between human and animal feeding? 712. What is gained by the rational feeding of both humans and animals? 713. What use can be made of the results of dietary studies for improvement of the dietary? 714. Why is it not possible for animal foods to compete in economy with cereal and vegetable foods? 715. Is a well-balanced ration and one containing an ample supply of nutrients necessarily an expensive ration? 716. Show how it is possible for one family to spend less money for food than another family, and yet secure more digestible nutrients and energy. 717. What are some of the most erroneous ideas as to food values? 718. Why is it necessary to consider previously acquired food habits in the selection of foods? 719. In general, what portion of the nutrients of a ration should be derived from vegetable foods, and what portion from meats? 720. To what extent may a ration vary from the dietary standards? 721. Why are some inexpensive foods often expensive when prepared for the table? 722. What are some of the ways in which the cost of a ration can be decreased without sacrificing nutritive value? 723. Why do different nationalities acquire distinct food habits? 724. Why is it not possible to make sudden and radical changes in the dietary? 725. Why is it not possible for a dietary which gives ample satisfaction for one cla.s.s of people to be applied to another cla.s.s with equal satisfaction? 726. What relationship exists between the dietary of a nation and its physical development?

727. What relationship exists between dietary habits and mental development and vigor? 728. Why is it unnecessary and undesirable to regulate absolutely the amount of nutrients consumed in the daily ration? 729. What is the general tendency as to quant.i.ty of food and amount of nutrients consumed? 730. Why do people of sedentary habits require a different dietary from those pursuing active, out-of-door occupations?

CHAPTER XVIII

RATIONAL FEEDING OF MAN

731. What is the object of the rational feeding of man? 732. On what is it based? 733. How does it compare with the rational feeding of animals?

734. What is a standard ration? 735. How is it determined? 736. To what extent may the nutrients of a ration vary from the standard? 737. How do you combine foods to form a balanced ration? 738. What foods are valuable for supplying protein? 739. What foods supply fats? 740. What foods are rich in carbohydrates? 741. What other requisites should a ration have in addition to supplying the necessary nutrients? 742. Why is it necessary to consider the calorie value of a ration? 743. If a ration contained an excess of carbohydrates and a scant amount of protein, how could it be improved? 744. How do you calculate the nutrients in a fraction of a pound of food? 745. Give the amounts of the common food materials, as potatoes, bread, b.u.t.ter, milk, and cheese, ordinarily combined to form a ration. 746. To what extent may foods differ in composition from the average a.n.a.lysis given? 747. What foods are subject to the greatest and what foods to the least variation?

CHAPTER XIX

WATER

748. Why is water regarded as a food? 749. Does it enter chemically into the composition of plants? Of animals? 750. In addition to serving as a food, why is water necessary for life processes? 751. In what ways may water be improved? 752. What are the most common forms of impurities?

753. What are the mineral impurities of water? 754. What is their source? 755. What effect do some of these minerals have upon the value of the water? 756. What causes some waters to dissolve limestone? 757.

What are permanently hard waters? 758. To what is temporary hardness in water due? 759. What is the best way to remove mineral matter from water? 760. What are the organic impurities of water? 761. What are the sources of the organic impurities? 762. What change does the organic matter of water undergo? 763. What becomes of the nitrogen of the organic matter? 764. What does the presence of nitrates in water indicate? Nitrites? 765. What is the total solid matter of a water, and how is it obtained? 766. Define the terms free ammonia; alb.u.minoid ammonia. 767. What does the presence of chlorine in a surface well water indicate? 768. Explain natural purification of water. 769. Can natural purification always be relied upon? 770. Why does the character of the drinking water affect health? 771. What diseases are mainly caused by impure drinking water? 772. With what materials in water are the disease-producing organisms a.s.sociated? 773. Why should a water of questionable purity be boiled? 774. State how the boiling should be done, to be effective. 775. Why should boiled water receive further care in its storage? 776. What effect does improvement of the water supply of a city have upon the death rate? 777. How may connections between cesspools and surface well waters be traced? 778. What impurities do rain waters contain? 779. Explain the workings of the Pasteur and Berkefeld water filters. 780. Why must special attention be given to cleaning the water filter? 781. Explain the processes employed for the removal of mechanical impurities of water by sedimentation and the use of chemicals. 782. Why should such purification be under the supervision of a chemist or bacteriologist? 783. What effect does freezing have upon the purity of water? 784. Why are precautions necessary in the use of ice for refrigeration? 785. What are mineral waters? 786. How are artificial mineral waters prepared? 787. What are the more common materials used in their preparation? 788. Why should mineral waters be extensively used only by the advice of a physician? 789. What are some of the materials used for softening water? 790. Which are the least objectionable of these materials? 791. Which are the most objectionable?

792. What can you say of the use of ammonia and ammonium carbonate for softening waters? 793. In washing clothing after contagious diseases, what materials may be used for disinfecting? 794. Why, in softening waters for household purposes, must caustic soda, potash, and bleaching powder be used with caution? 795. Why is it necessary to determine by trial the material most suitable for softening water? 796. What advantage, from a pecuniary point of view, results from the improvement of the water supply of a community?

CHAPTER XX

FOOD IN ITS RELATION TO HOUSEHOLD SANITATION AND STORAGE

797. What are the compounds usually determined in a food a.n.a.lysis? 798.

Does such an a.n.a.lysis necessarily indicate the presence of injurious compounds? 799. What are the sources of the injurious organic compounds in foods? 800. Why is it necessary to consider sanitary condition as well as chemical composition? 801. What are the sources of contamination of foods? 802. What is the object of the sanitary inspection of food?

803. How may flies carry germ diseases? 804. Why should food be protected from impure air and dust particles? 805. Why should places where vegetables are stored be well ventilated? 806. How may the dirt adhering to vegetables be the carrier of germ diseases? 807. Why should the cellar in which food is stored be in a sanitary condition? 808. What effect does the cleaning of streets and improvement of the sanitation of cities have upon the death rate? 809. Name the three natural disinfectants, and explain the action of each. 810. Why must dishes and utensils in which foods are placed be thoroughly cleaned? 811. Explain the principle of refrigeration. 812. What kind of ferment action may take place at a low temperature? 813. Why is some ventilation necessary in refrigeration? 814. What effect does refrigeration have upon the composition of food? 815. What relationship exists between unsanitary condition of soils about dwellings and contamination of the food? 816.

Why should special attention be given to the sanitary disposal of kitchen refuse? 817. Name the ways in which this can be accomplished.

818. How may foods become contaminated through imperfect plumbing? 819.

Mention the conditions necessary in order to keep foods sanitary.

REFERENCES

The following list of references is given for the use of the student in case additional information is desired upon some of the subjects discussed in this work. The list is not intended as a complete bibliography of the subject of foods. The advanced student will find extended references in the Experiment Station Record and the various chemical, physiological, and bacteriological journals.

1. SNYDER: The Chemistry of Plant and Animal Life.

2. Minnesota Experiment Station Bulletin No. 54: Human Food Investigations.

3. CROSS AND BEVANS: Cellulose.

4. WILEY: Principles and Practice of Agricultural a.n.a.lysis, Vol. III.

5. Minnesota Experiment Station Bulletin No. 74: Human Food Investigations.

6. PARRY: The Chemistry of Essential Oils, etc.

7. U. S. Department of Agriculture, Farmers' Bulletin No. 142: Principles of Nutrition and Nutritive Value of Food.

8. MANN: Chemistry of the Proteids.

9. Minnesota Experiment Station Bulletin No. 85: Wheat and Flour Investigations.

10. ARMSBY: Principles of Animal Nutrition.

11. SHERMAN: Organic a.n.a.lysis.

12. U. S. Department of Agriculture, Office of Experiment Stations Bulletin No. 43: Digestion Experiments with Potatoes and Eggs.

13. Unpublished results of author.

14. U. S. Department of Agriculture, Bureau of Animal Industry Bulletin No. 49: Cold Curing of Cheese.

15. WILEY: Foods and Their Adulteration.

16. Minnesota Experiment Station Bulletin No. 63: Miscellaneous a.n.a.lyses.

17. U. S. Department of Agriculture, Bureau of Chemistry Bulletin No.

13, Part 8: Canned Vegetables.

18. LEACH: Food Inspection and a.n.a.lysis.

19. U. S. Department of Agriculture, Farmers' Bulletin No. 256: Preparation of Vegetables for the Table.

20. U. S. Department of Agriculture Year Book, 1905: Fruit and its Uses as Food.

21. Handbook of Experiment Station Work, 1893.

22. U. S. Department of Agriculture, Division of Chemistry Bulletin No.

94: Studies on Apples.

23. U. S. Department of Agriculture, Bureau of Chemistry Bulletin No.

69: Fruits and Fruit Products.