Vinegars, Spices, and Condiments
569. What is vinegar? 570. How is it made? 571. Give the three chemical changes that take place in its preparation. 572. Why is air necessary in the last stage of the process? 573. What ferments take part in the production of vinegar? 574. What is malt vinegar? 575. What materials other than apples can be used in the preparation of vinegar? 576. Give the characteristics of a good vinegar. 577. In what ways are vinegars adulterated? 578. What food value has vinegar? 579. Why should vinegars not be stored in metalware? 580. What dietetic value has vinegar? 581. To what materials do the spices owe their value? 582. What is pepper? 583. What is the difference between white and black pepper? 584. What compounds give pepper its characteristics? 585. How are peppers adulterated? 586. What is mustard? 587. Give its general composition. 588. How is it adulterated? 589. What is ginger? 590. How is it prepared for the market? 591. Give its general composition. 592. What is cinnamon? 593. What is cassia? 594. What gives these their taste and flavor? 595. What are cloves? 596. How are they prepared? 597. What is mace? 598. What is nutmeg? 599. Do the spices have any food value? 600. What is their dietetic value? 601. Why is excessive use of some of the spices objectionable?
CHAPTER XIV
Tea, Coffee, Chocolate, and Cocoa
602. What is tea? Name the two plants from which it is obtained, the countries where each grows best, and the number of flushes each yields. 603. Upon what does the quality and grade of tea depend? 604. Give differences in the preparation and composition of green and black teas. 605. The characteristic flavor of tea is imparted by what compound? 606. To what compound are its peculiar physiological properties due? 607. What can you say of the protein in tea as to amount and food value? 608. Why should tea—especially green tea—be infused for a very short time, never boiled? 609. What effect has tannin upon the digestion of proteids? 610. What three points are considered in judging a tea? 611. What is the most common form of tea adulteration? 612. Describe the coffee plant and fruit, and its method of preparation for market. 613. What is the difference in the chemical composition of tea and coffee? 614. Name the characteristic alkaloid of coffee. How does it compare with theme? 615. Why may coffee not be considered a food? 616. Tell different ways in which coffee may be adulterated. 617. Which is more commonly practiced, tea or coffee adulteration? Why? 618. How may real coffee be distinguished from chicory? Why? 619. Name the three kinds of coffee in general use. Give distinguishing features of each. Which is usually considered best? 620. From what are cocoa and chocolate obtained? 621. Give the two methods of preparing cocoa. 622. What alkaloid similar to the theme and caffeine of tea and coffee is present in cocoa and chocolate? 623. What is the difference in preparation of cocoa and chocolate? 624. What are cereal coffee-substitutes? 625. What nutritive value have they? 626. How do they differ in composition from coffee? 627. To what extent does cocoa add to the nutritive value of a ration? 628. What is plain chocolate? 629. Why do chocolate preparations vary so widely in composition? 630. What treatment is given to the cocoa bean in its preparation for commerce? 631. What treatment is sometimes given to prevent separation of the cocoa fat? 632. In what ways may cocoa and chocolate preparations be adulterated?
CHAPTER XV
Digestibility of Foods
633. Define the term nutrient. 634. Do all the nutrients of food have the same degree of digestibility? 635. What is a digestion coefficient? 636. How is the digestibility of a food determined? 637. What volatile products are formed during the digestion of food? 638. Define digestible protein; digestible carbohydrates, digestible fat. 639. What is the available energy of a ration? 640. How is it determined? 641. How do the nutrients, protein, fat, and carbohydrates, compare as to available energy? 642. Why is it necessary to consider the caloric value of a ration? 643. Is the protein molecule as completely oxidized in the body as starch or fat? 644. What residue is left from the digestion of protein? 645. What part do the soluble ferments take in digestion? 646. To what extent are the nutrients of animal foods digested? 647. Which nutrient, protein or fat, is the most completely digested? 648. How do vegetable foods compare in digestibility with animal foods? 649. What effect does cellulose have upon digestibility? 650. Which of the nutrients of vegetables, protein or carbohydrates, is more completely digested? 651. What mechanical value may cellulose have in a ration? 652. Why must bulk be considered in a ration, as well as nutrient content? 653. Name the eight most important factors influencing the digestibility of foods. 654. To what extent does the combination of foods affect the digestibility of the nutrients? 655. Why does a mixed ration give better results than when only a single food is used? 656. How does the amount consumed affect the completeness of the digestive process? 657. To what extent does the method of preparing food affect digestibility? 658. What is gained, so far as digestibility is concerned, by the cooking of foods? 659. To what extent does the mechanical condition of food affect its digestibility? 660. Why is it desirable to have some coarsely granulated foods in a ration? 661. Why should the ration not be composed exclusively of finely granulated foods? 662. Why is some coarsely granulated food more essential in the dietary of the sedentary than in the dietary of the laborer? 663. How does palatability affect the digestive process? 664. Do psychological processes in any way affect digestion? 665. What physiological properties do some foods possess? 666. To what are these physiological properties due? 667. To what extent is individuality a factor in digestion? 668. To what extent does digestibility differ with individuals? 669. Why do some foods affect individuals in different ways? 670. Why is it necessary that the quantity, quality, and character of the food should vary with different individuals? 671. In what different ways is the expression "digestibility of a food" used? 672. Why is it necessary to consider the digestibility of food, as well as its composition? 673. Does the digestibility of a food necessarily indicate the economic uses that will be made of it by the body? 674. How is it possible for one food containing 10 per cent of digestible protein, and other nutrients in like amounts, to be more valuable than another food with the same per cent of digestible protein and other nutrients? 675. How is it possible for one food to contain less total protein than another food and yet be more valuable from a nutritive point of view? 676. Why is it necessary to consider the mechanical condition of a food and its combination with other foods, as well as its chemical composition? 677. What effect does lack of a good supply of air have upon the completeness of the digestion process? 678. In what ways does the digestion of food resemble the combustion of fuel? 679. What is gained by a study of the digestibility of foods? 680. Why may two foods of the same general character give different results when used for nutritive purposes?