1、Part 2 食品科技英语的阅读,本部分教学内容,Part 2 食品科技英语的阅读,Lesson 3 Amino acids,Part 2 食品科技英语的阅读,Lesson 3 Amino acids,20种常见的蛋白质氨基酸,Isoleucine 异亮氨酸(Ile,I),Serine 丝氨酸(Ser,S),Threonine 苏氨酸(Thr,T),Proline 脯氨酸(Pro,P),Lysine 赖氨酸(Lys,K),Aspartic acid 天冬氨酸(Asp,D),Glutamic acid 谷氨酸(Glu,E),Part 2 食品科技英语的阅读,Lesson 3 Amino acid
2、s,Part 2 食品科技英语的阅读,Hydrolysate n.水解产物 Racemic adj. 外消旋的 Isomer n. 异构体 Acylase n.酰基转移酶 Deregulate n.解除管制 Auxotrophic adj. 营养缺陷型的，营养缺陷体的 Intermediate adj. 中间的 n.媒介，中间物 Eliminate v.排除，消除 Analogue n.相似物，类似情况，对等的人 Revertant n. adj. 回复子(的)，回复突变型(的),Lesson 3 Amino acids,Part 2 食品科技英语的阅读,Amino acids are pro
3、duced using a range of technologies including direct fermentation, biotransformation of precursors using cells or enzymes, extraction of protein hydrolysates and chemical synthesis. They have a variety of uses as nutrients and flavours in the food and feed industries.,Lesson 3 Amino acids,Para.1,Par
4、t 2 食品科技英语的阅读,Lesson 3 Amino acids,a range of 一系列的，很多的 1. a range of fruit-flavoured toppings （蛋糕上的各种果味配料） 2. Control of a range of food related microorganisms by a multi-parameter preservation system （利用多参数保藏系统控制一系列食品相关微生物） a variety of 多种的，各种各样的 1. a variety of food is sold at a supermarket （超级市场各
5、式各样的食物均有出售） 2. a new variety of apples（苹果的新品种） A series of 一系列，许多,Table 1 indicates the annual demand, production methods and applications of amino acids in the food industry. Important amino acids with non-food applications include L-arginine, L-gludtamine, L-histidine, L-leucine, L-phenylalanine,
6、L-tyrosine and L-valine.,Lesson 3 Amino acids,Para.1,Part 2 食品科技英语的阅读,While fermentation or biotransformation processes have been developed for production of all amino acids except glycine, L-cysteine and L-cystine, not all of these processes are commercially viable. L-asparagine, L-leucine, L-tyros
7、ine, L-cysteine, and L-cystine are produced by purification of protein hydrolysates.,Lesson 3 Amino acids,Para.2,Part 2 食品科技英语的阅读,Chemical synthesis is more economical for production of optically-inactive racemic mixtures of D- and L-isomers, and D, L-alanine,D,L-methionine, D, L-tryptophan and glyc
8、ine are produced in this way. Processing involving amino acylase enzymes may be used to resolve these racemic mixtures.,Lesson 3 Amino acids,Para.2,Part 2 食品科技英语的阅读,Microbial strains from the genera Croynebacterium and Brevibacterium have assumed major importance in the production of amino acids by
9、fermentation. Natural isolates of these strains can excrete large quantities of glutamic acid. Because of cell metabolic regulatory mechanisms, particularly end-prodcut repression and inhibition, substantial levels of amino acids are rarely excreted by wild-type isolates.,Lesson 3 Amino acids,Para.3
10、,Part 2 食品科技英语的阅读,Production of commercial quantities of the amino acids has been dependent on the successful development of deregulated mutants. The two most important methods involve use of auxotrophic and regulatory mutants or a combination of the two.,Lesson 3 Amino acids,Para.3,Part 2 食品科技英语的阅读
11、,Auxotrophic mutants, which lack the enzyme needed to form the regulatory effector metabolite (often the end-product), many accumulate and excrete the metabolic intermediate which is the substrate for the eliminated enzyme. A lysine auxotroph, for example, lacks an enzyme in the pathway necessary fo
12、r lysine synthesis and requires lysine, or a metabolic precursor which can be converted to lysine, for growth.,Lesson 3 Amino acids,Para.3,Part 2 食品科技英语的阅读,End-product inhibition by the amino acid product of an unbranched biosynthetic pathway may be avoided by the development of regulatory mutants,
13、having an altered feedback-insensitive key enzyme, thus allowing accumulation of the particular amino acid.,Lesson 3 Amino acids,Para.3,Part 2 食品科技英语的阅读,Analogues of the end-product, which are also capable of inhibition of the sensitive key enzyme, may be used in screening methods for selection of a
14、nalogue-resistant or regulatory mutants. Revertants may be selected from auxotrophic mutants (apparently lacking the key regulatory enzyme) which produce a modified deregulated enzyme.,Lesson 3 Amino acids,Para.3,Part 2 食品科技英语的阅读,Lesson 3 Amino acids,1. 熟练掌握20种常见的氨基酸的英文单词 2. Indicate, show等的用法 3. 掌握
15、相关构词法。如：optically-inactive 无光学活性的 end-product 终产物 wide-type 野生型的analogue-resistant 类似物抑制,Part 2 食品科技英语的阅读,Lesson 3 Amino acids,071班翻译 Reading Material 1 072班翻译 Reading Material 2注意： 1、请按段落进行翻译。即每一段英文对应每一段中文。 2、作业下周四交。,Part 2 食品科技英语的阅读,Lesson 4 Yogurt Fermentation,Part 2 食品科技英语的阅读,coagulum n. 凝结物，凝固物
16、 lactose n. 乳糖 stir v. 搅拌 Lactobacillus n. 乳酸杆菌 Bulgaricus n. 保加利亚乳杆菌 Streptococcus n. 链球菌 Thermmophilus n. 嗜热链球菌 Stimulating adj. 刺激的，有刺激的 Casein n. 干酪素，酪蛋白 Sodium n. 钠 Flora n. 区系 Intestinal adj. 肠的，肠内的，（疾病）侵袭肠的,Lesson 4 Yogurt Fermentation,Part 2 食品科技英语的阅读,You have 5 minutes to read Paragraph 1,a
17、nd then answer the following questions:1.What does “this fermented dairy product” mean?2. What does “the aforementioned cultures” refer to?,Lesson 4 Yogurt Fermentation,Yogurt,the starter culture contains Lactobacillus bulgaricus and Streptococcus thermophilus.,Part 2 食品科技英语的阅读,Yogurt is another wel
18、l-known fermented dairy product that forms an important part of the human diet in many parts of the world. In the United States alone, 1979 sales figures indicated that more than 565 million pounds of this fermented dairy product were sold.,Lesson 4 Yogurt Fermentation,Para.1,Part 2 食品科技英语的阅读,Depend
19、ing on the system of manufacture and the nature of the coagulum, yogurts may be classified as being of two main types, set or stirred. Two lactose-fermenting bacteria, Lactobacillus bulgaricus and Streptococcus thermophilus, are used as the starter culture to make yogurt. Equal numbers of L. bulgari
20、cus and S. thermophilus are desirable for flavor and texture production.,Lesson 4 Yogurt Fermentation,Para.1,Part 2 食品科技英语的阅读,classify v. 1）将（某事物）编排、分类；2）将某人（事物）归类习惯表达方式： be classified (by/according to)classify sb./sth. (as sth.),Lesson 4 Yogurt Fermentation,e.g. 1)Yogurt may be classified set and s
21、tirred according to the system of manufacture and the nature of the coagulum. 2)They are classified in sorts.(它们是按品种分类的。),Part 2 食品科技英语的阅读,starter culture 发酵剂 e.g. Study on High Activity Lyophilized Starter Culture of Yoghurt（高活性酸奶冻干发酵剂的研究 ）,Lesson 4 Yogurt Fermentation,leaven n. 酵母, 促使渐变的因素vt. 使发酵,
22、 渐变 【医】 发酵剂, 曲,同义词,Part 2 食品科技英语的阅读,The lactobacilli grow first, liberating the amino acids glycine and histidine and stimulating the growth of streptococci. The production of the characteristic flavor by the aforementioned culture is a function of time as well as the sugar content of the starting y
23、ogurt material.,Lesson 4 Yogurt Fermentation,Para.1,Part 2 食品科技英语的阅读,Commercially, yogurt is made from a mix of whole, partially defatted milk; condensed skim milk; cream; and nonfat dry milk. Milk fat levels in such preparations range from 1.0% to 3.25%. Only products containing a minimum of 3.25%
24、milk fat are labeled yogurt. Those with 0.5% to 2.0% or less than 0.5% milk fat are labeled low-fat and nonfat yogurts, respectively.,Lesson 4 Yogurt Fermentation,Para.2,Part 2 食品科技英语的阅读,a minimum of 至少，最低，最起码 e.g. 1.He smoke a minimum of ten cigarettes a day. （他每天至少抽10支烟。）2. Are ample exercise and
25、a minimum of food measures for cancer prevention?(充足的锻炼和少量的食物可以防癌吗？),Lesson 4 Yogurt Fermentation,a maximum of /less than /at most,近义词,more than 多于，高于 ；at least，至少,反义词,Part 2 食品科技英语的阅读,In addition to milk fat, other milk ingredients are found in yogurt. These include casein, sodium and calcium casei
26、nates, whey, and whey protein concentrates. Additives of several kinds are also permitted in commercially produced yogurt, such as nutritive carbohydrate sweeteners, coloring, stabilizers ( for smooth texture and longer shelf life), and fruit preparations for flavoring.,Lesson 4 Yogurt Fermentation,
27、Para.2,Part 2 食品科技英语的阅读,Fruit preparations for blending in yogurt are specially designed to meet the marketing requirements for different types of yogurt. The types most commonly marketed include the sundae style (fruit preserves are layered on the bottom of containers) and the Swiss style (fruit pr
28、eparations are thoroughly blended in yogurt after culturing).,Lesson 4 Yogurt Fermentation,Para.2,Part 2 食品科技英语的阅读,The product is prepared by reducing the water content of either whole or skim milk by at least one fourth (may be done in a vacuum pan following sterilization of milk), by adding about
29、5% milk solids followed by water reduction (condensing). The concentrated milk is then heated to 82-93 for 30-60minutes and cooled to around 45.,Lesson 4 Yogurt Fermentation,Para.3,either,or,Part 2 食品科技英语的阅读,The yogurt starter is now added at a level of around 2% by volume and incubated at 45 for 3-
30、5 hours followed by cooling to 5 . The titratable acidity of a good finished product is around 0.85-0.9%, and to get this amount of acidity the fermenting product should be removed from 45 when the titratable acidity is around 0.65-0.7%.,Lesson 4 Yogurt Fermentation,Para.3,Part 2 食品科技英语的阅读,“大约”的几种表达
31、方法 at a level of around/around about e.g. The yield was reduced by about 5 percent. The yield was reduced to 95 percent. approximate,Lesson 4 Yogurt Fermentation,Part 2 食品科技英语的阅读,Good yogurt keeps well at 5 for 1-2 weeks. The coccus grows first during the fermentation followed by the rod, so that af
32、ter around 3 hours, the numbers of the two organisms should be approximately equal.,Lesson 4 Yogurt Fermentation,Para.3,Part 2 食品科技英语的阅读,Higher amounts of acidity, such as 4%, can be achieved by allowing the product to ferment longer, with the effect that the rods will exceed the cocci in number. Th
33、e streptococci tend to be inhibited at pH values of 4.2-4.4, whereas the lactobacilli can tolerate pH values in the 3.5-3.8 range.,Lesson 4 Yogurt Fermentation,Para.3,Part 2 食品科技英语的阅读,Yogurt and other cultured dairy foods are excellent sources of high-quality protein and certain B-complex vitamins a
34、nd minerals. In addition to the nutritional importance of yogurt, it has been found to be of value in maintaining a balance in the intestinal microbial flora.,Lesson 4 Yogurt Fermentation,Para.4,Part 2 食品科技英语的阅读,1、掌握有关酸奶知识的固定表达短语和句子. （ fermented dairy product发酵乳制品 ， starter culture 发酵剂， skim milk 脱脂乳，dry milk,奶粉， milk solids 牛奶固形物the concentrated milk炼乳 ） 2、能熟练掌握“大约”（a minimum/maximum of），“classify” ,“culture”等的用法。 3、掌握描述试验过程的英文撰写手法。,Lesson 4 Yogurt Fermentation,Thank you for your cooperation!,
