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1、 油脂工程专业英语油脂工程专业英语练练习题习题 一、一、Translate the following technical terms into English. 1. 饱和脂肪酸 2. 油酸 3. 花生蛋白 4. 全脂豆粉 5. 分离蛋白 6. 棕榈油 7. 游离脂肪酸 8. 油脂分提 9. 蛋白质功能性 10. 油脂酯交换 11. 甘三酯 12. 酸值 13. 氨基酸 14. 溶剂浸出 15. 压榨 16. 蒸发 17. 汽提 18. 过滤 19. 离心机 20. 等电点 21 皂 22 棉籽 23 溶剂 24 脱色 25 压榨 26 游离脂肪酸 27 粕 28 脱壳 29 油脂 30 碳
2、水化合物 二、二、Translate the following technical terms into Chinese 1. diglyceride 2. lecithin 3. pigment 4. linolenic acid 5. saponification 6. cholesterol 7. wax 8. peroxide value 9. full-fat soybean flour 10. refined oil 11. emulsion stability 12. gelation 13. alkali refining 14. deodorization 15. wate
3、r holding capacity 16. miscella 17. rapeseed oil 18. crude oil 19. edible oil 20. vegetable protein 21.triglyceride 22.tocopherol 23.esterification 24.unsaturation 25.oxidative stability 26. rancidity 27.deodorizer 28.meal 29.degummed oil 30. saponification 31. antioxidant 32. lipoxidase 33. moistur
4、e 34. vacuum 35. sesame 36. scavenger 37. impurity 38. hydrophilic 39. isomer 40. degradation 三、三、Read the following materials carefully, and finish the questions SECTION I After solvent extraction, the soybeans were separated into two fractions - oil and meal. Each one of the fractions is then furt
5、her processed to yield a multitude of products and by-products, with practically no waste. For the oil fraction, in general, it is used to produce edible oil by a series of operations known as refining. The first step in refining crude soybean oil is degumming, the removal of the phospholipids mainl
6、y. Degumming is necessary in order to prevent the separation and settling of gums (sticky, viscous oil-water emulsions stabilized by the phospholipids) during transportation and storage of crude oil. Crude oil is mixed thoroughly with a small amount of water and an acid (usually phosphoric acid). (1
7、) Gums are formed and precipitated, carrying in the emulsion a certain amount of oil. They are separated by centrifugation, dried under vacuum and bleached. The resulting product consists approximately of 50% phospholipids and 50% oil. Crude soybean oil contains typically 0.3 to 0.7% free fatty acid
8、s. In the chemical or alkali refining process, the most common process applied to soybean oil, the fatty acids are neutralized with alkali to form salts (soaps) insoluble in oil. (2) Treatment with alkali solutions also removes residues of phospholipids not removed by degumming and results in some d
9、egree of bleaching due to the destruction of some of the pigments or their adsorption by the heavy phase. The resulting aqueous soap solution, known as soap stock is removed from the neutralized oil by centrifugation. The next step of refining is bleaching. Its purpose is to remove the yellow-orange
10、 carotenoid pigments and the green chlorophyll of the oil. The extent of bleaching depends on market requirements. (3) Bleaching is carried out by treating the oil with solid adsorbents such as activated earth or activated carbon or both. The pigments and some other impurities are adsorbed on the so
11、lid surface and removed by filtration. In order to prevent oxidation, the process is carried out under vacuum. The last refining operation is deodorization. It consists in the removal of odorous substances by steam distillation under high vacuum and at high temperature. (4) The main objective of deo
12、dorization is the removal of odor-bearing compounds such as aldehydes, low molecular fatty acids, ketones and hydrocarbons, other substances such as sterols and tocopherols are also distilled off. For the meal fraction, normally, it is used to produce vegetable proteins for food and feed. Soybean me
13、al as animal feedstuff By far the largest portion of the soybean oil meal and cake production is used as a protein source in animal feed. (5) Although the terms meal and cake are often used interchangeably, meal refers to the product of solvent extraction, while cake is the product resulting from th
14、e press of soybeans. The different types of soybean meals are characterized mainly by their protein content and the extent of heat treatment applied in their production to inactivate anti-nutritional factors. If the soybeans are extracted without dehulling,or if the hulls are added back after extrac
15、tion, the meal will contain about 44% protein. Meals produced from dehulled beans contains approximately 50% protein. Defatted soybean flours and grits These products, intended for human consumption, are essentially soybean meal which has been ground to the appropriate mesh size. The starting materi
16、al is dehulled beans and strict sanitary requirements are applied to processing, storage and packaging conditions, in order to secure the microbiological quality of the final product. (6) In addition, a large variety of products, differing in their lipid content are produced by adding-back soybean o
17、il and/or lecithin to defatted flour or grits at specified levels. Soybean protein concentrates (7) Soybean protein concentrates, containing more than 70% protein are prepared from defatted meal by selective extraction of the soluble carbohydrates with suitable solution. Extraction with aqueous alco
18、hol is the most common process, but other methods of production are available. The concentrates are essentially bland. Soybean protein isolates (8) Soybean protein isolates, containing more than 90% protein are obtained by alkaline extraction of the protein, followed by precipitation of the protein
19、in the extract near to the isoelectric point. Isoelectric isolates are insoluble in water and have practically no functional features. They can be converted to sodium, potassium or calcium proteinates by dissolving isoelectric protein in the appropriate base and spray-drying the solution. Sodium and
20、 potassium proteinates are water soluble. They are used mainly for their functional properties, such as emulsification or foaming. One of the by-products of the protein isolation process, the insoluble residue, is also commercialized for its remarkable water absorption capacity and as a source of di
21、etary fiber. 1. Choosing the best answer for the blanks. (1) The major aim of degumming is removal of during the refining processing of crude soybean oil. A. free fatty acids B. polyaromatic hydrocarbons C. phospholipids D. soaps (2) The free fatty acids in the crude soybean oil are removed in the o
22、peration of refining process. A. fractionation B. neutralization C. bleaching D. hydrolysis (3) The is/are removed in the bleaching step of refining processing of soybean oil. A. Free fatty acids B. Triglycerides C. Water D. Pigments (4) The off-flavors in the soybean oil are removed in the step of
23、the refining process. A. hydrogenation B. dewaxing C. deodorization D. degumming (5) During alkali refining, the free fatty acids react with alkali to form . A. soaps B. hydratable fatty acids C. lecithin D. fatty acid stock. (6) For the dehulled soybean meal, the protein content is . A. about 38% B
24、. about 50% C. higher than 75% D. higher than 85% (7) The protein content of soybean protein concentrate is . A. about 40% B. about 50% C. higher than 90% D. higher than 70% (8) The protein content of soybean protein isolate is . A. about 40% B. about 55% C. higher than 90% D. higher than 80% (9) In
25、 the most common cases, the soybean protein concentrate is produced from defatted meal by selective extraction of the soluble polysaccharides with . A. anhydrous alcohol B. aqueous alcohol solution C. caustic water D. hexane (10) The soy flour and grit are produced from soy meal or cake by grinding
26、and screening, however, the particle size of grit is that of flour. A. larger than B. smaller than C. equal to D. similar to 2. Translating the following sentences into Chinese. (1) Gums are formed and precipitated, carrying in the emulsion a certain amount of oil. They are separated by centrifugati
27、on, dried under vacuum and bleached. The resulting product consists approximately of 50% phospholipids and 50% oil. (2) Treatment with alkali solutions also removes residues of phospholipids not removed by degumming and results in some degree of bleaching due to the destruction of some of the pigmen
28、ts or their adsorption by the heavy phase. (3) Bleaching is carried out by treating the oil with solid adsorbents such as activated earth or activated carbon or both. The pigments and some other impurities are adsorbed on the solid surface and removed by filtration. (4) The main objective of deodori
29、zation is the removal of odor-bearing compounds such as aldehydes, low molecular fatty acids, ketones and hydrocarbons, other substances such as sterols and tocopherols are also distilled off. (5) Although the terms meal and cake are often used interchangeably, meal refers to the product of solvent
30、extraction, while cake is the product resulting from the press of soybeans. (6) In addition, a large variety of products, differing in their lipid content are produced by adding-back soybean oil and/or lecithin to defatted flour or grits at specified levels. (7) Soybean protein concentrates, contain
31、ing more than 70% protein are prepared from defatted meal by selective extraction of the soluble carbohydrates with suitable solution. (8) Soybean protein isolates, containing more than 90% protein are obtained by alkaline extraction of the protein, followed by precipitation of the protein in the ex
32、tract near to the isoelectric point. SECTION II There are two major types of oil refining: chemical and physical. (1)The major steps involved in chemical refining include degumming, neutralizing, bleaching, and deodorizing. Physical refining removes free fatty acids and flavors by distillation, to c
33、ombine the steps of neutralization and deodorization into one operation. Degumming is a water-washing process to remove phosphatides. Unless removed, phosphatides can spontaneously hydrate from moisture in the air during storage or in the headspace. (2)Degumming may be conducted either as a separate
34、 operation or simultaneously with neutralization. In the cases of oils rich in phosphatides, such as soybean and canola oil, degumming is usually a separate operation. The process generally involves treating the crude oil with a limited amount of water to hydrate the phosphatides and make them separ
35、able by centrifugation. The phosphatides are often recovered and further processed to yield a variety of lecithin products. Alkali refining (Neutralization) generally is performed on vegetable oils to reduce the free fatty acid content and to remove other gross impurities such as phosphatides, prote
36、inaceous, and mucilaginous substances. By far the most important and widespread method of refining is the treatment of the fat or oil with an alkali solution. (3)This results in a large reduction of free fatty acids through their conversion into water-soluble soaps. Most phosphatides and mucilaginou
37、s substances are soluble in the oil only in an anhydrous form and upon hydration with the caustic or other refining solution are readily separated. Oils low in phosphatide content (palm and coconut) may be physically refined (i.e., steam stripped) to remove free fatty acids. After alkali refining, t
38、he fat or oil is water-washed to remove residual soap. The term “bleaching” refers to the process for removing color producing substances and for further purifying the fat or oil. Normally, bleaching is accomplished after the oil has been refined. The usual method of bleaching is by adsorption of th
39、e color producing substances on an adsorbent material. Acid-activated bleaching earth or clay, sometimes called bentonite, is the adsorbent material that has been used most extensively. This substance consists primarily of hydrated aluminum silicate. Anhydrous silica gel and activated carbon also ar
40、e used as bleaching adsorbents to a limited extent. The purpose of deodorization of oils and fats is removing trace constituents that give rise to undesirable flavors, colors and odors in fats and oils. (4)The deodorization process is simply a removal of the relatively volatile components from the f
41、at or oil using a vacuum steam distillation. This is feasible because of the great differences in volatility between the substances that give flavors, colors and odors to fats and oils and the triglycerides. Normally this process is accomplished after refining and bleaching. Deodorization does not h
42、ave any significant effect upon the fatty acid composition of most fats or oils. In the case of vegetable oils, sufficient tocopherols remain in the finished oils after deodorization to provide stability. * * * By far the largest portion of the soybean meal and cake production is used as a protein s
43、ource in animal feed. The different types of soybean meals are characterized mainly by their protein content and the extent of heat treatment applied in their production to inactivate anti-nutritional factors. (5)If the soybeans are extracted without dehulling, or if the hulls are added back after e
44、xtraction, the meal will contain about 44% protein. Meal produced from dehulled beans contains approximately 50% protein. Defatted soybean flours, intended for human consumption, are essentially soybean meal which has been ground to the appropriate mesh size. The starting material is dehulled beans
45、and strict sanitary requirements are applied to processing, storage and packaging conditions, in order to secure the microbiological quality of the final product. (6) Soybean protein concentrates, containing more than 70% protein are prepared from defatted meal by selective extraction of the soluble
46、 carbohydrates with suitable solution. Extraction with aqueous alcohol is the most common process, but other methods of production are available. The concentrates are essentially bland. (7)Soybean protein isolates, containing more than 90% protein are obtained by alkaline extraction of the protein,
47、followed by precipitation of the protein in the extract near to the isoelectric point. Isoelectric isolates are insoluble in water and have practically no functional features. They can be converted to sodium, potassium or calcium proteinates by dissolving isoelectric protein in the appropriate base
48、and spray-drying the solution. Sodium and potassium proteinates are water soluble. They are used mainly for their functional properties, such as emulsification or foaming. One of the by-products of the protein isolation process, the insoluble residue, is also commercialized for its remarkable water
49、absorption capacity and as a source of dietary fibre. Functional properties of isolated soy proteins can be grouped into several related classes according to the principal physicochemical causes. (8)Hydration and water absorption, solubility, viscosity, and gelation properties are different manifest
50、ations of the common protein-water and protein-protein interactions that occur in protein slurries. Emulsification and foaming properties result from the behavior of proteins at oil-water or air-water interfaces. Color, flavor, and odor properties are due primarily to small nonprotein components. 1.
51、 Choosing the best answer for the blanks. （1）The main aim of degumming is the removal of during the refining processing of crude oil. A. free fatty acid B. polyaromatic hydrocarbon C. phosphatides D. tocopherols （2）The free fatty acids in the crude oil are removed in the operation of refining proces
52、s. A. fractionation B. neutralization C. bleaching D. hydrolysis （3）The method of bleaching is by . A. adsorption B. oxidation C. degradation D. desorption （4）The off-flavors in the oil are removed in the step of refining process. A. deodorization B. oxidation C. degumming D. hydrolysis （5）During th
53、e degumming process, after hydration, the gums are separated by normally . A. washing B. absorption C. oxidation D. centrifugation （6）The main method of refining is the treatment of the fat or oil with . A. hexane B. alkali solution C. alcohol D. adsorbent （7）Deodorization does not have any signific
54、ant effect upon the of most fats or oils. A. tocopherol content B. sterol content C. triglyceride composition D. fatty acid composition （8）The different types of soybean meals are characterized mainly by . A. their protein content B. the color C. the extent of heat treatment D. A and C （9）Soybean pr
55、otein isolates, contain more than protein. A. 44% B. 50% C. 70% D. 90% （10）Emulsification and foaming properties of proteins result from . A. the common protein-water and protein-protein interactions B. the water absorption capacity C. the behavior of proteins at oil-water or air-water interfaces D.
56、 the protein content. 2. Translating the following sentences into Chinese. (1)The major steps involved in chemical refining include degumming, neutralizing, bleaching, and deodorizing. Physical refining removes free fatty acids and flavors by distillation, to combine the steps of neutralization and
57、deodorization into one operation. (2)Degumming may be conducted either as a separate operation or simultaneously with neutralization. In the cases of oils rich in phosphatides, such as soybean and canola oil, degumming is usually a separate operation. (3)This results in a large reduction of free fat
58、ty acids through their conversion into water-soluble soaps. (4)The deodorization process is simply a removal of the relatively volatile components from the fat or oil using a vacuum steam distillation. (5) If the soybeans are extracted without dehulling, or if the hulls are added back after extracti
59、on, the meal will contain about 44% protein. Meal produced from dehulled beans contains approximately 50% protein. (6) Soybean protein concentrates, containing more than 70% protein are prepared from defatted meal by selective extraction of the soluble carbohydrates with suitable solution. (7) Soybe
60、an protein isolates, containing more than 90% protein are obtained by alkaline extraction of the protein, followed by precipitation of the protein in the extract near to the isoelectric point. (8)Hydration and water absorption, solubility, viscosity, and gelation properties are different manifestati
61、ons of the common protein-water and protein-protein interactions that occur in protein slurries. SECTION III The oxidation of fatty acids results in the development of undesirable flavors that can lead to unacceptable food quality. Lipid oxidation and loss of flavor quality is probably the most freq
62、uent cause of deterioration in foods that are not otherwise subjected to microbial spoilage. The shelf-life of products like breakfast cereals, frozen meats, potato chips, and edible oils themselves, is limited by oxidation. Besides producing off flavors, lipid oxidation can cause the lose of essent
63、ial fatty acids needed for human nutrition, fading of pigments, destruction of fat soluble vitamins, and the production of potentially harmful compounds from the oxidized fat. The number of double bonds in a fatty acid or fat source is a good indication of the potential for lipid oxidation. Any oil
64、source that is high in unsaturation should be viewed as very susceptible to degradation. Fish oil is an extreme example of a highly unsaturated oil that is very unstable in a food system. The oxidation reaction involves the formation of highly reactive free radical compounds that develop as a result
65、 of the double bond. Lipid oxidation in foods has an induction period where the reaction may seem slow or nonexistent. But with time, the speed of the reaction increases and efforts to stop or slow the progress at this point are futile. Oxygen becomes involved in the reaction by forming peroxides an
66、d hydroperoxides on the affected fatty acids. The next step is the decomposition of the fatty acid into lower molecular weight compounds such as aldehydes and acids. These compounds may have potent flavors themselves or further react to cause other favor problems. A final step in the reaction is tha
67、t free radical fatty acid may react with each other to form larger molecular weight compounds. The oil may become more viscous and discolored. At this stage in the reaction, the flavor compounds are likely to be au objectionable that the product is inedible. 1. According to the text, the following s
68、tatement is true or false? A. Food is not easy to subjected to microbial spoilage. B. The more number of double bonds in a fatty acid or fat source, the less susceptible to degradation of the fat. 2. Explain the result of lipid oxidation. 3. The shelf-life of some products is limited by oxidation, w
69、hat are the products? 4.What kind of compounds may have potent flavors and further react to cause other favor problem? 5. At the last stage of oxidation, why may the oil become more viscous and discolored? SECTION IV A variety of mean are used to inhibit lipid oxidation. The use of more saturated fa
70、ts and more hydrogenation of unsaturated fats will decrease the susceptibility to oxidation. However more unsaturated fats are desired for health reasons, lipid oxidation problems have to be solved by other means such as, packaging, storage conditions, antioxidants, and processing parameters. While
71、there are exception, lipid oxidation can be thought of as storage reaction rather than a heatinduced reaction. Nonetheless, temperature plays a role and cool, as opposed to warm temperature, are recommended for storage of oxidation 一 sensitive food. Light promotes lipid oxidation, so opaque or color
72、ed packaging and protection from visible and ultraviolet tight are preventative measures. Mixing oxidized oil, even in small amounts, with fresh oil will allow the reaction to skip past mach of the induction period and therefore take place at an accelerated rate. The peroxides and free radicals in t
73、he old oil will expedite the formation of off-flavors. Oxygen is one of the reactants and is a strong promoter of the reaction. Any measures to eliminate air or oxygen from the food will slow lipid oxidation. The nature of most foods will not allow complete expulsion of air, but vacuum packaging (fo
74、r roasted peanuts), nitrogen flushing (for potato chips), and oxygen impermeable packaging (foil lining for some snack foods) can all be helpful in inhibiting the reaction. The effects of water content on lipid oxidation are mixed because in dry foods such as powders and dried cereal products, lower
75、ing the moisture even further will promote oxidation. Under other circumstances, increases in water content or Aw can increase the extent of oxidation. Metal ions such as iron and copper are catalysts for lipid oxidation. The presence of these metals in processing equipment, water, oils, or other fo
76、od ingredients should be looked upon as sources of pro 一oxidants. Some antioxidants such as citric acid are used to bind or chelate metal ions, thereby destroying the catalytic activity. Naturally occurring antioxidants such as vitamin E and -carotene can slow the rate of oxidation as will the addit
77、ion of synthetic antioxidants such as TBHQ (tertiary butyl hydroquinone) , BHA (butylated hydroxy anisole) and BHT (butylated hydroxy toluene) .The power of these antioxidants is limited and they can only be used in low levels. Normally，a combination or preventative measures must be used against lip
78、id oxidation in foods containing unsaturated fats and even then, the product will have a limited shelf 一 life because of the reaction. 1. According to the text, the following statement is true or false? A. Mixing oxidized oil with fresh oil will slow down the reaction of oxidation. B. Under all circ
79、umstances, lowering the moisture content will promote the extent of oxidation. 2. What kind of means can be used to inhibit lipid oxidation? 3. What kind of measures can be used to eliminate or reduce air or oxygen thus slow the oxidation reaction? 4. Which antioxidant can be used to chelate metal i
80、ons? Write down some natural and synthetic antioxidants, respectively. 四、四、Filling the blanks with suitable English words. 1. Fats and oils are recognized as essential in both human and animal diets. 2. Because of the presence of double bonds, fatty acids are more reactive chemically than are satura
81、ted fatty acids. This reactivity increases as the of double bonds increases. 3. The addition of antioxidants to fats or foods containing them retard rancidity and increases and shelf life. 4. Hydrolysis is the splitting reaction of fat with to form and free fatty acids. 5. Degumming is the process t
82、hat removes phosphatide compounds from oils prior to . 6. Salad and cooking oils are prepared from oils that are refined, , deodorized, and sometimes dewaxed or lightly hydrogenated and winterized. 7. Triglycerides are resulted from the combination of one unit of and units of fatty acids. 8. Salad a
83、nd cooking oils are prepared from oils that are refined, , deodorized, and sometimes dewaxed or lightly hydrogenated and winterized. 9. The two important types of isomerism among fatty acids are (1) geometric and (2) . 10. Winterization is a process whereby material is crystallized and removed from
84、the oil by to avoid clouding of the liquid fraction at temperatures. 五、五、Make the right choice to complete each statement. 1. Which one of the following is one kind of di-unsaturated fatty acid? ( ) A. stearic acid B. linoleic acid C. oleic acid D. palmitic acid 2. Emulsifier is the compound having
85、the ability to reduce surface tension at the ( ). A.oil phase B. water phase C. interface D.outside layer 3. Medium chain triglyceride contain fatty acid chains of ( ) carbon atoms. A. 6-10 B.10-16 C. 16-18 D.18-22 4. Conjugated fatty acids are polyunsaturated fatty acids exhibiting ( ) or more of u
86、nsaturated carbons atoms not separated by a saturated carbon atom. A. one B. two C. three D. zero 5. Interesterification is used principally in confectionery fats, table spreads, shortenings, and margarines to maintain ( ) at ambient temperatures. A. liquid fat content B. solid fat content C. satura
87、ted fat content D. unsaturated fat content 6. Food allergies are caused by the ( ) components of food. A. protein B. fat C. carbohydrate D. minor 7. Butter is an important source of vitamin A, and to a lesser extent, of vitamin ( ). A. vitamin C B. vitamin D C. vitamin K D. vitamin E 8. Polymerize i
88、s the bonding of similar molecules into ( ) chains or branched structures. A. long B. short C. the same D. the reduced 9. When rancidity has progressed significantly, it becomes readily apparent from ( ) of the oil. A. the color B. the flavor and odor C. the uniformity D. the hardness 10. The deodor
89、ization of fats and oils is simply a removal of the relatively volatile components from the fat or oil using ( ). A. alkali B. citric acid C. water D. steam 11. Which one of the following is one kind of monounsaturated fatty acid? ( ) A. stearic acid B. linoleic acid C. oleic acid D. palmitic acid 1
90、2. The typical iodine value for unhydrogenated soybean oil is ( ). A.30 B. 90-95 C. 105-120 D.125-140 13. Medium chain triglyceride contain fatty acid chains of ( ) carbon atoms. A. 6-10 B.10-16 C. 16-18 D.18-22 14. ( ) are the chief form of fat in foods. A. Olestra B. Phospholipids C. Sterols D. Tr
91、iglycerides 15. Interesterification is used principally in confectionery fats, table spreads, shortenings, and margarines to maintain ( ) at ambient temperatures. A. liquid fat content B. solid fat content C. saturated fat content D. unsaturated fat content 16. Scientists generally agree that diets
92、high in trans fats tend to increase serum LDL cholesterol, thus suggesting a ( ) relationship with increased risk of coronary heart disease. A. positive B. negative C. great D. tiny 17. Emulsifiers, either present naturally in one or more of the ingredients or added separately, provide ( ). A. surfa
93、ce tension B. phase separation C. emulsion stability D. oxidative stability 18. Oils low in phosphatide content (palm and coconut) may be physically refined (i.e., steam stripped) to remove ( ). A. phosphatide B. water C. proteins D. free fatty acids 19. When rancidity has progressed significantly, it becomes readily apparent from ( ) of the oil. A. the color B. the flavor and odor C. the uniformity D. the hardness 20. The triglycerides are stored in the adipose tissue until they are needed as a source of ( ). A. calories B. lipoproteins C. metabolism D. digestion
