Human Foods and Their Nutritive Value Part 22

1. To what extent is water present in foods? 2. What foods contain the most, and what foods the least water? 3. How does the water content of some foods vary with the hydroscopicity of the air? 4. How may changes in water content of foods affect their weight? 5. Why is it necessary to consider the water content of foods in a.s.signing nutritive values? 6.

How is the dry matter of a food determined? 7. Why is the determination of the water in a food often a difficult process? 8. What is the ash or mineral matter of a food? 9. How is it obtained? 10. What is its source?

11. Of what is the ash of plants composed? 12. What part in plant life do these ash elements take? 13. Name the ash elements essential for plant growth. 14. Which of the mineral elements take the most essential part in animal nutrition? 15. In what form are these elements usually considered most valuable? 16. Why is sodium chloride or common salt necessary for animal life? 17. How do food materials differ in ash content? 18. Define organic matter of foods. 19. How is it obtained? 20.

Of what is it composed? 21. Into what is the organic matter converted when it is burned? 22. Give the two large cla.s.ses of organic compounds found in food materials. 23. Name the various subdivisions of the non-nitrogenous compounds. 24. What are the carbohydrates? 25. Give their general composition. 26. What is cellulose? 27. Where is it found?

28. What is its function in plants? 29. What is its food value? 30. In what way may cellulose be of value in a ration? 31. In what way may it impart a negative value to a ration? 32. What is starch? 33. Where is it mainly found in plants? 34. Give the mechanical structure of the starch grain. 35. Why is starch insoluble in cold water? 36. How do starch grains from different sources differ in structure? 37. What effect does heat have upon starch? 38. Define hydration of starch. 39.

Under what conditions does this change take place? 40. What value as a nutrient does starch possess? 41. What is sugar? 42. How does it resemble and how differ in composition from starch? 43. What are the pectose substances? 44. How are they affected by heat? 45. What food value do they possess? 46. What is nitrogen-free-extract? 47. How is it obtained? 48. How may the nitrogen-free-extract of one food differ from that of another? 49. What are the fats? 50. How do they differ in composition from the starches? 51. Why does fat when burned or digested produce more heat than starch or sugar? 52. Name the separate fats of which animal and vegetable foods are composed. 53. Give some of the physical characteristics of fat. 54. What is the iodine absorption number of a fat? 55. How does the specific gravity of fat compare with that of water? 56. Into what two const.i.tuents may all fats be separated?

57. What is ether extract? 58. How does the ether extract in fats vary in composition and nutritive value? 59. What are the organic acids? 60.

Name those most commonly met with in foods. 61. What nutritive value do they possess? 62. What dietetic value? 63. What value are they to the growing plant? 64. What organic acids are found in animal foods? 65.

What are the essential oils? 66. How do they differ from the fixed oils, or fats? 67. What property do the essential oils impart to foods? 68.

What food value do they possess? 69. What dietetic value? 70. What are the mixed compounds? 71. How may a compound impart a negative value to a food? 72. What is the nutritive value of the non-nitrogenous compounds, taken as a cla.s.s? 73. Why is it necessary that nitrogenous and non-nitrogenous compounds be blended in a ration? 74. What are the nitrogenous compounds? 75. How do they differ from the non-nitrogenous compounds? 76. Name the four subdivisions of the nitrogenous compounds.

77. What is protein? 78. What is characteristic as to its nitrogen content? 79. What are some of the derivative products that can be obtained from the protein molecule? 80. How does the protein content of animal bodies compare with that of plants? 81. Name the various subdivisions of the proteins. 82. What is alb.u.min, and how may it be obtained from a food? 83. What is globulin, and how is it obtained from a food? 84. Give some examples of globulins. 85. What are the alb.u.minates, and how are they affected by the action of acids and alkalies? 86. What are the peptones, and how do they differ from the alb.u.mins? 87. How are the peptones produced from other proteids? 88.

What are the insoluble proteids? 89. Give an example. 90. Which of the proteids are found to the greatest extent in foods? 91. Why may proteids from different sources vary in their nutritive value? 92. What general change do the proteids undergo during digestion? 93. What is crude protein? 94. How is the crude protein content of a food calculated? 95.

Why is the nitrogen content of a food more absolute than the crude protein content? 96. What food value do the proteins possess? 97. Why may proteins serve so many functions in the body? 98. Why is protein necessary as a nutrient? 99. What is the effect of an excess of protein in the ration? 100. What is the effect of a scant amount of protein in a ration? 101. What are the alb.u.minoids? 102. Name borne materials that contain large amounts of alb.u.minoids. 103. What food value do the alb.u.minoids possess? 104. What are the amids? 105. How are they formed in plants? 106. What is their source in animals? 107. What general changes does the element nitrogen undergo in plant and animal bodies?

108. What is the food value of the amids? 109. What are the alkaloids?

110. What is their food value? 111. What effect do some alkaloids exert upon the animal body? 112. How may they be produced in animal foods?

113. What general relationship exists between the various nitrogenous compounds? 114. Why is it essential that the animal body be supplied with nitrogenous food in the form of proteids? 115. Name the cycle of changes through which the element nitrogen pa.s.ses in plant and animal bodies.

CHAPTER II

CHANGES IN COMPOSITION OF FOODS DURING COOKING AND PREPARATION

116. How do raw and cooked foods compare in general composition? 117. In what ways are foods acted upon during cooking? 118. What causes chemical changes to take place during cooking? 119. What are the princ.i.p.al compounds that are changed during the process of cooking? 120. How does cooking affect the cellulose of foods? 121. What change does starch undergo during cooking? 122. When foods containing starch are baked, what change occurs? 123. How are the sugars acted upon when foods are cooked? 124. What effect does dry heat have upon sugar? 125. What change occurs to the fats during cooking? 126. How does this affect nutritive value? 127. What changes do the proteids undergo during cooking? 128.

Why does the action of heat affect various proteids in different ways?

129. Why are chemical changes, as hydration, often desirable in the cooking and preparation of foods? 130. What physical changes do vegetable and animal tissues undergo when cooked? 131. How do foods change in weight during cooking? 132. Why is a prolonged high temperature unnecessary to secure the best results in cooking? 133. To what extent is the energy of fuels utilized for producing mechanical and chemical changes in foods during cooking? 134. What effect does cooking have upon the bacterial flora of foods? 135. In what ways do bacteria exert a favorable influence in the preparation of foods? 136. How may certain cla.s.ses of bacteria exert unfavorable changes in the preparation of foods? 137. What are the insoluble ferments? 138. What are the soluble ferments? 139. What part do they take in animal and plant nutrition? 140. Define aerobic ferments. 141. Define anaerobic ferments.

142. What general relationship exists between the chemical, physical, and bacteriological changes that take place in foods? 143. Why should foods also possess an esthetic value? 144. What kinds of colors should be used in the preparation of foods? 145. What processes should be used for removal of coloring materials from foods?

CHAPTER III

VEGETABLE FOODS

146. Give the general composition of vegetable foods as a cla.s.s. 147.

How do vegetable foods differ from animal foods? 148. Name some vegetables which contain the maximum, and some which contain the minimum percentage of protein. 149. Give the general composition of potatoes.

150. Of what is the dry matter mainly composed? 151. How much of the crude protein of potatoes is true protein? 152. What ratio exists between the nitrogenous and non-nitrogenous compounds in the potato?

153. Give the chemical composition of the potato. 154. What influence do different methods of boiling have upon the crude protein content of potatoes? 155. To what extent are the nutrients of potatoes digested and absorbed by the body? 156. What value do potatoes impart to the ration?

157. How do sweet potatoes differ in chemical composition and food value from white potatoes? 158. How do carrots differ in composition from potatoes? 159. What is characteristic of the dry matter of the carrot?

160. How do carrots and milk differ in composition? 161. To what is the color of the carrot due? 162. To what extent are the nutrients removed in the cooking of carrots? 163. What is the value of carrots in a ration? 164. Give the characteristics of the composition of parsnips.

165. How does the starch of parsnips differ from that of potatoes? 166.

How does the mineral matter of parsnips differ from that of potatoes?

167. How does the cabbage differ in general composition from many vegetables? 168. To what extent are nutrients extracted in the boiling of cabbage? 169. Give the nutritive value of cabbage. 170. How does the cauliflower differ from cabbage? 171. Give the general composition of beets. 172. Give the general composition of cuc.u.mbers. 173. What nutritive value has lettuce? 174. Give the composition and dietetic value of onions. 175. How does the ratio of nitrogenous and non-nitrogenous compounds in spinach differ from that in many other vegetables? 176. Give the general composition and nutritive value of asparagus. 177. How much nutritive material do melons contain? 178. What are the princ.i.p.al compounds of tomatoes? 179. What nutrients do they supply to the ration? 180. In the canning of tomatoes, why is it desirable to conserve the juices? 181. How does sweet corn differ in composition from fully matured corn? 182. What nutritive value does the egg plant possess? 183. What are the princ.i.p.al nutrients of squash? 184.

What nutritive material does celery contain? 185. To what does celery owe its dietetic value? 186. Why are vegetables necessary in a ration?

187. Why is it not possible to value many vegetable foods simply on the basis of percentage of nutrients present? 188. Name the miscellaneous compounds which many vegetables contain, and the characteristics which these may impart. 189. Why is it necessary to consider the sanitary conditions of vegetables? 190. How do canned vegetables differ in composition and food value from fresh vegetables? 191. What proportion of vegetables is refuse and non-edible parts? 192. Why is it necessary to consider the refuse of a food in determining its nutritive value?

CHAPTER IV

FRUITS

193. To what extent do fruits contain water and dry matter? 194. Give the general composition of fruits. 195. What compounds impart taste and flavor? 196. How much nutrients do fruits add to a ration? 197. Why is it not right to determine the value of fruits entirely on the basis of nutrients? 198. Give the general composition of apples? 199. What compound is present to the greatest extent in the dry matter of apples?

200. How do apples differ in composition? 201. Give the general physical composition of oranges. 202. What nutrients are present to the greatest extent in oranges? 203. How do lemons differ in composition from oranges? 204. How does grape fruit resemble and how differ in chemical composition from oranges and lemons? 205. What are the main compounds in strawberries? 206. In what ways are strawberries valuable in a ration?

207. Of what is grape juice mainly composed? 208. What acid is in grapes, and what is its commercial value? 209. To what are the differences in flavor and taste due? 210. How do ripe olives differ in composition from green olives? 211. What is the food value of the olive?

212. What physiological property does olive oil have? 213. What is the princ.i.p.al nutrient in peaches? 214. What compounds give flavor to peaches? 215. Of what does the dry matter of plums mainly consist? 216.

How do plums differ in composition from many other fruits? 217. What are prunes? What is their food value? 218. How do dried fruits differ in composition from fresh fruits? 219. What should be the stage of ripeness of fruit in order to secure the best results in canning? 220. How do canned fruits differ in composition and nutritive value from fresh fruits? 221. To what extent are metals dissolved by fruit juices? 222.

Why should tin in which canned goods are preserved be of good quality?

223. What preservatives are sometimes used in the preparation of canned fruits? 224. What is the objection to their use? 225. Why are fruits necessary in the ration? 226. What change does heat bring about in the pectose substances of fruits?

CHAPTER V

SUGAR, MOLa.s.sES, SIRUPS, HONEY, AND CONFECTIONS

227. What is sugar? 228. From what sources are sugars obtained? 229.

Name the two divisions into which sugars are divided. 230. How are sugars graded commercially? 231. What per cent of purity has granulated sugar? 232. How is the coloring material of sugar removed? 233. How is sugar treated to make it whiter? 234. What value as a nutrient does sugar possess? 235. Why should sugar be combined with other nutrients?

236. What foods contain appreciable amounts of sugar? 237. Why is an excessive amount of sugar in a ration undesirable? 238. Does sugar possess more than condimental value? 239. What is the average quant.i.ty of sugar consumed in this country? 240. What is maple sugar? 241. How does it differ in composition from other sugar? 242. How is adulterated maple sugar detected? 243. To what extent is granulated sugar adulterated? 244. Why is it not easily adulterated? 245. What are the dextrose sugars? 246. How do they differ chemically from sucrose? 247.

What is the inversion of sugar? 248. In what way does acid act upon sugar? 249. How are the acid products removed? 250. What is the food value of glucose? 251. What is mola.s.ses? 252. How is it obtained? 253.

Of what is it composed? 254. What gives taste and flavor to mola.s.ses?

255. How may mola.s.ses act upon metalware? 256. What is the food value of mola.s.ses? 257. What is sirup? 258. Name three kinds of sirup, and mention materials from which they are prepared. 259. What is the polariscope, and how is it employed in sugar work? 260. What is honey?

261. How does it differ in composition from sugar? 262. How is strained honey adulterated? 263. What materials are used in the preparation of confections? 264. What changes take place in their manufacture? 265.

What materials are used for imparting color? 266. What can you say in regard to the coal tar colors? 267. What should be the position of candy in the dietary? 268. What can you say of the comparative value of cane and beet sugar? 269. How do the commercial grades of sugar compare as to nutritive value? 270. What are some of the impurities in candy? 271.

What is saccharine? 272. What are its properties?

CHAPTER VI

LEGUMES AND NUTS

273. What nutrients do the legumes contain in comparatively large amounts? 274. How does the amount of this nutrient compare with that found in meats? 275. Why are legumes valuable crops in general farming and for the feeding of farm animals? 276. Give the general composition of beans. 277. How do beans compare in protein content with cereals?

278. How does the protein of beans differ from that of many other food materials? 279. To what extent are the nutrients of beans digested? 280.

What influence does the combination of beans with other foods have upon digestibility? 281. What influence does removal of skins have upon digestibility? 282. In what part of the digestive tract are beans mainly digested? 283. How does the cost of the nutrients in beans compare with that of the nutrients in other foods? 284. How do string beans differ from green beans? 285. Give the general composition, digestibility, and nutritive value of peas. 286. What can you say of the use of copper sulphate in the preparation of canned peas? 287. What nutrients do peanuts contain in large amounts? 288. Give the general composition of nuts. 289. What are the characteristics of pistachio? 290. Give the general composition of the cocoanut. 291. What is cocoanut b.u.t.ter? 292.

To what extent may nuts contribute to the nutritive value of a ration?

CHAPTER VII

MILK AND DAIRY PRODUCTS

293. What can you say as to the importance of dairy products in the dietary? 294. Give the general composition of milk. 295. What compound in milk is most variable? 296. To what extent are the nutrients in milk digestible? 297. What influence does milk have upon the digestibility of other foods? 298. Why is cheese cured in cold storage? 299. How can the tendency of a milk diet to produce costiveness be overcome? 300. Why is it necessary to consider the sanitary condition of milk? 301. What factors influence the sanitary condition of milk? 302. What is certified milk? 303. What is pasteurized milk? 304. How can milk be pasteurized for family use? 305. What is tyrotoxicon? 306. What is its source in milk? 307. To what is the color of milk due? 308. To what extent is color a.s.sociated with fat content? 309. What causes souring of milk?

310. What change occurs in the milk sugar? 311. What are the most favorable conditions for the souring of milk? 312. What are some of the preservatives used in milk. 313. What objection is urged against their use? 314. What is condensed milk? 315. What is b.u.t.termilk, and what dietetic value has it? 316. How does goats' milk differ from cows' milk?

317. What is koumiss, and how is it prepared? 318. What are the prepared milks? 319. How does human milk differ in composition from cows' milk?

320. Give the nutritive value of skim milk. 321. What content of fat should cream contain? 322. In what ways is milk adulterated? 323. How are these adulterations detected? 324. Give the general composition of b.u.t.ter. 325. What is the maximum amount of water that a b.u.t.ter may contain without being considered adulterated? 326. What can you say in regard to the digestibility of b.u.t.ter? 327. How is b.u.t.ter adulterated?

328. How does oleomargarine compare in digestibility and food value with b.u.t.ter? 329. What is the food value of b.u.t.ter? 330. How does cheese differ in composition from b.u.t.ter? 331. Give the general composition of cheese. 332. To what are the flavor and odor of cheese due? 333. Why is cheese ripened? 334. What chemical changes take place during ripening?

335. To what extent are the nutrients of cheese digested? 336. Why is cheese sometimes considered indigestible? 337. To what extent do the nutrients of different kinds of cheese vary in digestibility? 338. How does cheese compare in nutritive value and cost with meats? 339. What is cottage cheese? 340. What is Roquefort cheese? 341. Name four kinds of cheese, and say to what each owes its individuality. 342. How is cheese adulterated? 343. Why are dairy products in older agricultural regions generally cheaper than meats?

CHAPTER VIII

MEATS AND ANIMAL FOOD PRODUCTS

344. Give the general composition of meats. 345. How do meats differ in chemical composition from vegetable foods? 346. What is the princ.i.p.al non-nitrogenous compound of meats, and what of vegetables? 347. Name the different cla.s.ses of proteins in meats. 348. Which cla.s.s is present in largest amounts? 349. To what extent are amid compounds present in meats? 350. What characteristics do amids impart to meats? 351. How are alkaloids produced in meats? 352. In what ways does the lean meat of different kinds of animals vary chemically and physically? 353. Give the general composition of beef. 354. What relationship exists between the fat and water content of beef? 355. How much refuse have meats? 356. In what forms are the ash elements (mineral matter) present in meats? 357.