食品专业--外文文献翻译
食品专业--外文文献翻译
基于对海栖热孢菌来源的α-L-阿拉伯呋喃糖苷酶的结构分析揭示其热稳定性和底物特异性特征从海栖热孢菌MSB8中提取的α-L-阿拉伯呋喃糖苷酶(TmAFase)是一种高耐热性半纤维素外切酶,与其他51糖苷水解酶家族的酶相比较，作用于阿拉伯糖和木聚糖时显示出了相对较高的活性。
在目前的研究中，我们完成了关于阿拉伯糖苷酶的酶动力学特性和结构分析的工作。
在海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）中发现的紧密领域协同作用,比如在每一个单体上的一个域间二硫键(Cys306和Cys476),在二聚物的界面上的一个新的延伸臂(氨基酸374-385),和六聚体上的所有12个盐桥,应该是酶的热稳定性的原因。
木聚糖聚合力的决定因素之一(Trp96)被确认是在活性部位,一定范围的氨基酸(374 - 385)突出隆起在底物结合位点生成一个凹点并形成一个明显的墙层来。
蚀变性的小洞形状，带有一个强大的负静电分布，可能与海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）的支化聚合物基质与独特的结构衬底有关。
关键词：海栖热孢菌阿拉伯糖苷酶结构分析X-衍射结晶学半纤维素是由各种戊糖糖、己糖糖,糖和酸组成的最丰富、可再生多相聚合物之一。
最近,研究人员正高度关注在半纤维素等各种可发酵糖的高效分解，生物燃料和化学品的生产方面。
由于半纤维素生物质在结构上极高的复杂性和可变性,因而,几个半纤维素酶的协同作用主要包括裂解开链外切-β-(1,4)木聚糖酶和β-xylosidases和侧面消除开链辅助酶,对这些生物质材料的完全降解至关重要。
α-L-阿拉伯呋喃糖苷酶(AFase; E.C. 3.2.1.55)是最重要的辅助酶,这种酶可以催化水解的终端那些非还原性的α-L -(1、2),α-L -(1,3),和α-L -(1、5)-arabinofuranosyl 残留物来源于arabinose-containing多糖,如阿拉伯多糖和阿糖基木聚糖。
食品英语文献综述范文
食品英语文献综述范文Title: The Language of Food: Exploring Culinary Delights in EnglishFood is a universal language that speaks to us all, transcending borders and connecting cultures through the shared experience of flavor. In this essay, I will delve into the world of food, exploring its many facets and the rich vocabulary that accompanies it.At the heart of every great meal is the ingredients list, a collection of culinary building blocks that, when combined with care and precision, create gastronomic masterpieces. From the crisp tang of fresh vegetables to the savory depth of tender meats, each component plays a vital role in the final flavor profile. Understanding these elements is crucial for any aspiring chef or food enthusiast.Moving beyond the individual ingredients, we encounter the vast array of cooking techniques that transform them into delectable dishes. Whether it's the slow simmer of a traditional stew, the rapid sizzle of a stir-fry, or the delicate nuance of sous-vide, each method imparts unique qualities to the food. Mastery of these skills requires both knowledge and practice, honed over time through trial and error.But food is not just about the process; it's also about the result. The presentation of a dish can be just as important as its taste, with visual appeal setting the stage for the gustatory journey ahead. A beautifully plated meal can evoke anticipation and excitement, enhancing the dining experience before a single bite is taken.Of course, no discussion of food would be complete without mentioning the myriad flavors that define it. From the fiery kick of spices to the subtle sweetness of caramelized natural sugars, tastes are the ultimate test of a cook's mettle. Balancing these flavors requires a keen palate and a deep understanding of how different ingredients interact with one another.Finally, there's the cultural significance attached to food. Every cuisine reflects the history and traditions of its people, with each dish telling a story of heritage and identity. Sharing a meal is not just an act of sustenance; it's a celebration of community and connection.In conclusion, food is much more than mere sustenance; it's an art form, a science, and a cultural touchstone. By understanding the ingredients, techniques, presentation, flavors, and cultural significance of what we eat, we canappreciate the true beauty of culinary artistry. So next time you sit down to a meal, take a moment to savor not just the taste but also the intricate tapestry of knowledge and tradition that lies behind it.。
食品科学专业英译汉
Response of climacteric-type guava (Psidium guajava L.) to postharvesttreatment with 1-MCPS.P.Singh*,R.K.PalHandling and Storage Laboratory, Division of Postharvest Technology,ndianAgricultural Research Institute (IARI), Pusa, New Delhi 110012, India Abstract: Guava(Psidium guajava L. cv.‘Allahabad Safeda’) fruit harvested at the mature light-green stage were exposed to 300 and 600 nL/L 1-methylcyclopropene(1-MCP) for 6,12 and 24 h at 20±1℃, and held in either cold storage (10℃) for 25 days or ambient conditions (25-29℃) for 9 days.Most of the physiological and biochemical changes during storage and ripening were affected by 1-MCP in a dose dependent manner.Ethylene production and respirato ry rates were significantly suppressed during storage as well as ripening under both the storage conditions depending upon 1-MCP concentration and exposure duration. 1-MCP treatment had a pronounced effect on fruit firmness changes during storage under both the conditions.The reduced changes in the soluble solids contents (SSC),titratable acidity (TA) and vitamin C content showed the effectiveness of 1-MCP in retarding fruit ripening. Vitamin C content in 1-MCP-treated fruit was significantly higher than in no n-treated fruit, and those treated with 300 nL/L 1-MCP for 6 h.The development of chilling injury symptoms was ameliorated to a greater extent in 1-MCP-treated fruit during cold storage and ripening.A significant reduction in the decay incidence of 1-MCP-treated fruit was observed under both the storage conditions. 1-MCP at 600 nL/L for 12 h, in combination with cold storage (10℃) seems a promising way to extend the storage life of guava cv.‘Allahabad Safeda’ while 1-MCP at 300 nL/L for 12 and 24 h or 600 nL/L for 6 h, may be used to provide 4-5 days extended marketability of fruit under ambient conditions.Keywords: Ethylene; Respiration; Firmness; Vitamin C; Chilling injury; Decay文献来源：S.P. Singh∗, R.K. Pal.Response of climacteric-type guava (Psidium guajava L.) to postharvest treatment with 1-MCP[J].Postharvest Biology and Technology.2008, 47:307–314跃变期番石榴1-MCP采后处理的响应摘要：成熟到浅绿色的番石榴采收后在300-600nL/L 1-甲基环丙烯的环境中20±1℃存放6、12、24h，可以使之冷藏（10℃）25天，常温下（25-29℃）贮藏9天。
食品安全毕业设计论文外文文献翻译
毕业论文外文文献翻译Discussion on food supply chain management and food quality and safetySince the 1990s, supply chain management has become the academic and business circles hot topic, especially in supply chain management successfully applied to IBM, P & G, DELL, etc. after the company's management, food and agricultural industries have followed suit andSupply chain management with a tool to improve their competitiveness. 1996, Zuurbier and other scholars in general, on the basis of the supply chain, first proposed the concept of the food supply chain, and that the food supply chain management of agricultural and food production and marketing organization, food and agricultural products in order to reduce logistics costs and improve its quality and safety and logistics service level and for vertical integration mode of operation. Now, in the U.S., UK, Canada and the Netherlands and other more developed countries, agricultural production, this management model has been widely used, and gradually become the focus of academic research project.The food supply chain management research has gone through three stages: the first stage of the business flow management phase, the study of agricultural products and food processing enterprises, including the output of consumer spending to business before the flow phase, the content of their research is often included In the marketing context; the second stage of integrated logistics management phase, agricultural marketing, logistics management separate from, and to extend to the upstream producers of agricultural and food production process, emphasizing the production should be based on market demand and cost control throughout the supply chain; the third stage of supply chain integration management phase, the study extends further upstream to the most upstream agricultural enterprises (such as seed suppliers, etc.), the purpose is to extend the tracking and tracing of food quality and safety of agricultural products issues in order to quickly and effectively identify and solve problems. This article describes the production of different food supply chain logistics system characteristics, and the food supply chain management with the development of food quality and safety are analyzed and discussed.One. Food causes of supply chain managementIn recent years, the food supply chain, production and development of people's increasing demands for food consumption, the inevitable result. Specifically, the causes are: (1) the consumer fresh food and agricultural products have become increasingly demanding and require delivery of food and agricultural products, the production period as short as possible. (2) consumers of food and agricultural products quality requirements have become more sophisticated, forcing food manufacturers to implement the food supply chain management to ensure a stable supply of raw materials upstream and downstream sales channels. (3) food quality and safety of consumers are increasingly concerned about. In order to meet consumer demand for food and agricultural products in the type and quantity requirements, companies continue to seek and develop new technologies, and new technologies and new methods of excessive use (such as pesticides, hormones, antibiotics and genetically modified technology, etc.) to meet the consumer demand, but also inevitably produced a hazard causing human food quality and safety issues. This is because buyers and sellers in the market information asymmetry, consumers in the purchase of food or agricultural products, the products do not understand the health, environmental and safety information. Therefore, enterprises need in all aspects of the production process inspection and testing of products and timely disclosure of information to consumers. (4) food and agricultural companies forced the government, Relevant social organizations and consumer demands and pressure to press the food supply chain to operate. For example, EU regulations No. 178, as from 2004 in all EU-wide sales of food, must be implemented to track and trace food supply chain; the same in the United States Food and Drug Administration regulations in the United States and abroad engaged in food production, processing and packaging departments and related organizations in theDecember 12, 2003 to register the Food and Drug Administration for food safety tracking and tracing, on the allowed unregistered persons engaged in food production and sales. Thus, the food supply chain management is inherent in the market dynamics and the external pressure the government to promote the case.Two. Food supply chain, production logistics systemThe formation of the food supply chain logistics system with the changing content of closely related, particularly in the food and agricultural production logistics system evolving situation, for people to create a highly efficient food supply chain management paradigm provides the basis. According to food and agricultural products logistics stage of development, typical of the food supply chain can be divided into dumbbell-shaped, T-, symmetric and mixed four types.1．dumbbell food supply chain. This type of food supply chain is a quasi-strict supply chain. It is characterized by a shorter supply chain, connecting the main lot located at both ends of the transaction, while the middle of the main chain are few and fewer transactions, showing the dumbbell type. Upstream producers have poor technical conditions, production is low and less variety, it gathered a large number of upstream agricultural producers; the same time, products from the market to close and only a single farm, it also makes the chain in Most of the main trading agricultural producers, their direct trading in the market, and little contact between producers and consumers, middlemen, so growers sell directly to consumers food and agricultural products. In developing countries, especially near urban areas, the supply of vegetables, generally using this type of supply chain.2.T type of food supply chain. This type of food supply chains are generally applicable to food and agricultural production and sales of landto the far distance, consumer demand quite different situation. As perishable agricultural products, agricultural producers can not sell their products directly, through intermediaries to provide the necessary services, such as third-party logistics, agricultural processors and wholesalers provide appropriate services. This type of supply chain, upstream gathered more producers, and in the middle part of a better understanding of the origin of production, but also in the sales channels to occupy a certain advantage, but fewer vendors. Therefore, T-food supply chain and many growers, brokers and sellers and less downstream and concentrated, showing the shape of the supply chain for the T-type. And dumbbell-shaped compared to the food supply chain, which chain is longer, the sales performance of food and agricultural products and value-added services for the indirect nature. This type of food supply chains more common in China, China's agriculture industry in less developed regions, due to lack of upstream farmers to connect one end, other end of the link sales market, specializing in the processing of agricultural products among leading enterprises and the corresponding part of agricultural production often out of line with market demand. Therefore, T-middle part of the food supply chain as a low level of absence and logistics operation, prone to upstream farmers and downstream production of agricultural products sold blindly difficult phenomenon.3．symmetric food supply chain. With the emergence of new sales formats, distribution channels are increasingly large-scale professional market and supermarket monopoly, the traditional sales of agricultural products and food forms have been replaced by supermarkets, and this trend is more and more obvious, and because of its technological level of agricultural products production also tends to intensive management by a few growers. Boselie.D Ahe by the Royal Thai supermarket fresh food supply chain management survey found that 50% of Bangkok's food and agriculturalproducts in large supermarkets (such as 7-11, Royal Ahe, Carrefour, Sainsburry and TESCO) sold of. These large supermarkets in order to meet the market for agricultural products, quality consistency and supply stability requirements, the supplier of a rigorous screening. Therefore, the implementation of the Royal Ahe supermarket fresh food supply chain management, will be vendors from the original 250 was reduced to about 60, so that the logistics system more efficient and concise. With the upper reaches of the sharp drop in the number of suppliers of agricultural products and the continuous expansion of the supermarket chain, this food supply chain, upstream suppliers and downstream number of supermarket chains showed symmetrical growth trend. Logistics development in developed and more mature cities, this has been expressed in the food supply chain, centralized purchasing, reduce non-uniform flow distribution and value-added logistics sectors, in order to achieve cost savings of lean logistics strategy.4．mixed food supply chain. With consumer demand for food and agricultural products market diversification, the proportion of food and agricultural processing has gradually improved. According to the statistics that the United States in 2002 raw and processed vegetables for 15% and 85%; fruit of 30% and 70%. Other countries also generally the case. Large supermarkets in order to meet consumer demand significant changes to the original by an independent enterprise engaged in specialized production of value-added aspects of "internal" and specifically the establishment of large-scale processing and distribution center for agricultural products for cleaning, sorting, in-depth processing, packaging and distribution and other value-added services, through the implementation of HACCP in a large processing center and GMP certification process quality and health and safety, to ensure the quality of food and agricultural safety. The link is above three doesnot have the food supply chain, which is large supermarkets and chain stores to respond quickly to market demands results. With upstream suppliers to enhance the strength and advantages of the processing center part of the function, such as cleaning, sorting and depth of processing and other sectors Youxiang supplier back, making the processing center focused on the processing of agricultural products and expanding the number and type of business . Therefore, this food supply chain is a comprehensive, multi-species, multi-frequency high-volume and mix of supply chain system. This food supply chain are more concerned about customer satisfaction, through the processing centers to respond quickly to market demand, and real-time on agricultural products and foodstuffs "tailored" and depth of processing, in order to achieve different from the lean agile logistics logistics strategy.Three. Food supply chain tracking and food quality and safetyIn recent years, the focus of the food supply chain collaboration to ensure delivery of quality from the gradual move to reinforce the quality and safety of food and agricultural products, such as BSE, foot and mouth disease and the emergence of genetically modified foods. Agricultural products and food quality and safety of track without food supply chain management, so based on quality and safety of the food supply chain to track the food supply chain management has become important and difficult. Golan. E by the United States and other fresh produce, meat products, cereals and oilseed rape, and survey findings, three by the food supply chain tracking, food quality and safety in that there are great differences. The analysis of these differences, they also found that three agricultural products common food supply chain management, that there are three driving forces. This is also the corporate implementation of the food supply chain management requires analysis examines the question:1．will help differentiate the marketing of food and agricultural products to improve food and agricultural sales. Through those small or can not be directly found in food quality and safety features, can distinguish between different types of agricultural products and food. Because in the food and agricultural products on the market not only in large single grains and meat products, but also based on consumer preferences and tastes of different tailor-made food. Some agricultural products and food quality may be easier to distinguish, while others are not easy to directly determine, even after the consumer can not immediately find its quality. For example, transgenic edible oil, if not identified, the consumer it is difficult to determine whether the oil processed from non-genetically modified soybeans. Therefore, the quality of agricultural products and food safety and quality of the segmentation is a necessary prerequisite for differentiated marketing.2.is conducive to quality and safety of agricultural products and food tracking, reducing the cost of food and agricultural products recall. Many companies have used the food supply chain tracking systems to minimize food safety system deficiencies may result in potential losses. Suppliers often have a strong economy driven, when discovered food safety hazards and quality problems are, they tend to take measures to avoid food quality and safety issues to the companies themselves, or have a negative impact on the brand. Based on the food supply chain tracking can help businesses identify and reduce the time to clean up the food in question, for many foreign companies to reveal identifying information related to food packaging, to facilitate the identification of consumers and identified. For example, in the United States requested the recall of most food and agricultural products have been released in the United States Department of Agriculture Food Safety and Inspection Service's official website for consumers based on food packaging, identification information todetermine the question of food and agricultural products. Some companies are using advanced RSS bar code system and EAN / UCC Global unified identification system, more specifically reveal the identity of the food supply chain information, such as the product of each seed, fertilizer, use of antibiotics, production time, production lines, production , the production technology used and the production order, and so on. Therefore, a product if there are problems, these identification information will be able to play a significant role.Currently, the EU has adopted EAN / UCC system, successfully carried out on beef, vegetables and other food tracking research. By using EAN/UCC-128 bar code symbol, GLN (Global Location Number) to the food supply chain and the whole process of product attribute information and participants information for effective identification. Tracking and traceability in the food, the requirements of the supply chain process in every aspect, not only to complete the processing of their products for identification, but also to collect the necessary processing of food materials has been on the identification information, and all information identified in the processing of finished products, to prepare for the next part of a process or consumer use, in order to effectively solve the supply chain link between the weak, difficult to track and trace the problem, but also for companies to reduce by lack of clear information and good food will be mixed in with the poor quality of food processing with the possibility of high-quality food.3．will help enhance and improve the supply side of logistics management. For businesses, the management of production logistics and track-related retail information (such as bar code), to help businesses understand their food supply chain, logistics and outflow conditions for the supply chain for effective management of logistics flows. In particular, some businesses have adopted based on the quality and safetyof the food supply chain of high-tech tracking system, such as farmers use electronic ear identification cards and related data collection to track the immunization records of food and agricultural products, health records and breeding records. The food supply chain information can also make food or agricultural products in the market for its consistent quality and price.However, the implementation of all food and agricultural products quality and safety of the food supply chain tracking is not necessary. Van Weele, according to market information on agricultural and food needs of the food supply chain information to determine the track width, depth and accuracy. Similarly, companies in the food supply chain information to track width, depth and accuracy also reflects on the quality and safety of its food supply chain costs and benefits of an integrated approach. Because the information track width, depth and accuracy of a determinant of business investment in the food supply chain integration and cost. Only when the benefits outweigh the costs, the firm chosen width, depth and accuracy is the implementation of supply chain quality and safety of track power and assurance.论食品供应链管理和食品质量安全上世纪90年代以来,供应链管理已成为学术界和实业界关注的热门话题,特别是供应链管理成功地应用于IBM、P&G、DELL 等公司的经营管理以后,食品和农产品行业也纷纷效仿并借助供应链管理这一工具来提高自身的竞争力。
-食品科学与工程专业外文翻译、中英对照、英汉互译
毕业设计外文参考文献译文本2013届译文题目：Improvement of Soybean Oil Solvent Extraction throughEnzymatic Pretreatment酶法提取大豆油的改进设计题目：1500T/D棉籽预处理压榨车间工艺流程设计姓名：学号：院（系）：食品科学与工程学院专业：食品科学与工程指导老师：酶法提取大豆油的改进摘要:这项研究的目的在于评价多酶的水解作用作为预处理期间一个改善大豆油的溶剂萃取的选择以及它对传统工艺的适应结果。
酶的作用使得含油细胞结构降解。
对于提取物，产量和出油率的提高的预期得以实现。
大豆饼粕作为油料，正己烷作为溶剂。
最佳的温度，pH值和浸出时间，每一个固体的扩散系数都已经作了估计。
溶剂输送出来进入溶剂储藏罐中，油量是由时间决定的，数学模型足以用来描述这个系统。
对于大豆粕和饼的浸出，获得的最佳条件分别是pH值为5.4，温度为38℃，进出时间为9.7个小时以及PH值为5.8，温度为44℃，进出时间为5.8个小时。
氢化植物油固体展现出更高的产量。
扩散系数估计在10-11 与10-10之间。
氢化植物油固体拥有最大的扩散系数。
在大豆粕和大豆饼的浸出器里分别得到0.73克油每毫升和0.7克油每毫升，氢轻化植物油固体展现出更高的产量。
酶的催化提高了出油速率和出油量。
提议的模型被证明是适用的。
1 简介种子油类代表着70%的全球有产品，其中的30%是大豆油。
菜籽是出口阿根廷最重要的物料。
在菜籽中，细胞中的液泡含有油，细胞壁和液泡都必须被打破以达到改进溶剂提取效果。
因此，为了油最大限度的复原，在溶剂浸出前对油料的预处理是很严格的。
通过这种方法，大豆种子的细胞结构在适当酶的作用下，其水解作用将提高渗透率，因而提高浸出质量。
工业用途包含的酶处理阶段对于传统工艺没有明显变化。
通过这种方法使油释放出来将会获得更高的浸出产量和更少的有机溶剂使用。
在溶剂浸出过程中，经预处理后的油料（多空的固体模型）与纯溶剂或者混合溶剂相接处将油从固体模型中转运到液体介质中。
食品专业英语文选
Chapter 1. Food ScienceThe scientific study of food is one of man‘s most important endeavors, mainly because food is his most important need. It is necessary for his survival, his growth, his physical ability, and his good health. Food processing and handling is the largest of all of man‘s industries. Many factors require that those scientists who choose to study foods be prepared to absorb as much of the physical and life sciences and as much engineering as possible. Among these are the chemical complexity of foods, their vulnerability to spoilage, their role as a disease vector, and the varied sources of food. The availability nutritional adequacy, and wholesomeness of foods are also quite varied.Whether we now have enough of the facts to trace the development of food science from the beginning is questionable,. History reports that the Romans realized more than the Greeks, Egyptians, or any of the prior civilization, that agriculture was a prime concern of government. The Romans, as the Egyptians and the Greeks before them, were able to preserve a variety of foods by holding then them in vinegar (with or without brine), in honey, or in pitch. Some foods were also dried either by the sun or over a fire. Ancient civilizations produced cheeses and wines. Yet it is generally believed that until the later part of the 18thcentury the preservation of foods had evolved as an art handed down from generation to generation, .Its development was slow, depending on accidental discovery, observation, trial and error, and attempts to reproduce and pit into practice the newly found techniques. Drying, freezing, smoking, fermenting, cooking and baking had been practiced for centuries-even by illiterates. Foods frozen accidentally in cold climates and foods dried accidentally in dry climates were observed to have a longer shelf-life than foods which were neither frozen nor dried. Foods that might have been put over a fire to hasten drying could easily have led to the smoking process . Thus, chance occurrences led to preservation methods that permitted man to conserve foods during times of glut so that he might survive the leaner spells. It can be said, then, that those who made the observations and realized their impact and put their interpretations to the test, until the new practice was proven, were the first food scientists. Spallanzani(1765) and Apart(1795) were among the first to apply the quasi-scientific methods for preserving foods, and in 1809 Appert won a prize from the French Government for developing a thermal processing technique for foods to be used by the military. Appert is credited with developing the canning process. Because of the scarcity of sc ientific inf ormation, Appert had to employ trial and error tactics, but his records attest to the accuracy of his observations and conclusions and show that he applied the scientific approach to gain his outstanding achievement, even though he did not know why his method worked.It was not until the discoveries of Pasteur in 1850 and the work of other microbiologists such as pest and Underwood in 1895, that man learned that bacteria spoiled food and why thermal processing prevented food spoilage.By 1875 man had learned to preserve foods by artificial refrigeration using first natural ice, and later manufactured ice, to preserve fish and this enabled him to freeze foods. By 1890 mechanical refrigeration came into wide use, opening the way to the frozen storage of foods. Quick freezing wasFood Sciencefirst used in 1924 to preserve fish. During the period 1932-1934 Clarance Bird eye, with laboratories in Gloucester, Mass., developed over 100 different frozen food items, and this achievement won for him the reputation and the credit for the beginning of the quick-frozen food industry. One of the most important ensuing technological developments was the invention of the fish blacks by Brrdseye technologists. This is considered by many to have revolutionized the fish processing industry.In 1898 it was noted that bacteria were destroyed by exposure to radioactive salts of radium and uranium. By 1930 the use of ionizing radiation to preserve food was patented by O.Wust. But the irradiation preservation of foods was not actively investigated until 1943 by the team of Proctor, Van de Graaf, and Fram from the Massachusetts Institute of Technology.Modern technology has made possible the controlled, automated drying processes and sophisticated modifications such as freeze-drying, drum-drying, spraying-drying, fluidize-bed drying, etc. Controlled, automated versions of thermal and refrigeration processes have also been developed. Radiation processing (by election-, X-, and gamma-rays), microwave processing, and aseptic canning have also been introduced.Though many of the food processes alter foods in such a manner that the finished product is more palatable or otherwise more acceptable (to some at least) than original raw material (sauerkraut, tuna, wine, Roquefort cheese, etc.), in many cases it is desirable that preservation processes do not alter the food (fish fillets, beef steak, pork chops etc.)Only refrigeration can preserve most foods without altering them substantially.Words and Expressionsvinegar (n.) 醋brine (n./v.) 盐水；用盐水浸pitch (n.) 沥青smoke (v.) 熏制（肉，鱼）ferment (v.) 发酵fermentation (n.)shelf life 货架期preserve (v.) 保藏，保存preservation (n.)glut (n) 供过于求，过剩lean (a.) 欠收，不足thermal (a.) 热的canning process 罐藏加工bacteria (n.) 细菌microbiologist (n.) 微生物学家radioactive (a.) 放射性的radium (n.) 镭uranium (n.) 铀ionizing radiation 离子辐射drum-drying 转鼓干燥spray-drying 喷雾干燥fluidize-bed drying 流化床干燥microwave 微波aseptic (a.) 无菌的palatable (a.) 可口的sauerkraut (n.) 泡菜tuna (n.) 罐藏金枪鱼肉beef steak 牛排pork chops 猪排Chapter 2. CarbohydratesClassificationCarbohydrates are usually defined as polyhydroxy aldehydes and ketones or substances that hydrolyze to yield polyhydroxy aldehydes and ketones.Monosaccharides are classified according to (1)the number of carbon atoms present in the molecule and (2) whether they contain an aldehyde or keto group. Thus a monosaccharide containing six carbon atoms is called hexose; a monosaccharide containing an aldehyde group is called an aldose; and one containing a keto is called a ketose.The most important representatives of monosaccharides are glucose, arabinose, galactose, mannose, ribose, and fructose. Glucose is usually used as a carbon source for fermentation. Because the glucose in refined form such as crystallin form or as syrup form is more expensive, glucose in fermentation medium is mostly produced by directly enzymatic conversion of starch.The oligosaccharides can be classified into disaccharides and trisaccharides. The most important representatives of disaccharides are sucrose (from beet or cane), lactose, maltose and cellobiose. The most important representatives of trisaccharides is raffinose which occurs in sugar beet.Sucrose is available for use in fermentation processes either in crystallin form or in crude form as raw juice or mollasses ( a by-product of sugar manufacture). The sucrose contained in molasses is obviously cheaper, but the composition of molasses varies greatly with sources (cane or beet), quality of the crop and the nature of the sugar refining process. The molasses should be pretreated before being used as a raw material for fermentation medium.Lactose is present in whey (a by-product of cheese making that arise following the separation of curds, the solidified casein and butter fat) at a concentration of 4%-5% and whole whey or deproteinized whey is used as a cheap source of carbohydrate in some alcohol production process.Polysaccharides are constructed from monasaccharide unit and their derivatives, and have ten to several thousands units. D-glucose is the most common units. They are insoluble and nonreducing. The most important representatives are starch, glycogens, and cellulose.Starch is the most important carbohydrate used in fermentation processes. It is from plants such as corn, rice, wheat, potatoes and cassava.The extent of starch hydrolysis required varies with fermentation process and depends on considerations as to whether or not the microbial strain to be used produces amylase and whether product synthesis is subject to catabolite repression. For citric acid production , because the A.niger has the ability to synthesize glucoamylase ( or amyloglucosidase: a enzyme that catalyze the removal of one glucose molecule at a time from the terminal end of dextrins, breaking 1,4-links), the starch slurry is gelatinized by cooking at high temperature, then the gelatinized starch is liquefied and dextrinized by cooking at high temperature, and the saccharification step is not necessary. The soluble dextrin hydrolysate is used as a raw material for fermentation medium.CarbohydratesCarbohydrate Composition of FoodsDieticians Dietitians need more exact information on the carbohydrate composition of food. Food processors also make practical use of carbohydrate composition data. For example, the reducing sugar content of fruits and vegetables that are to dehydrated or processed with heat is frequently an indicator of the extent of nonenzymic browning that can be expected during processing and storage. The possible hydrolysis of sucrose to reducing sugar during processing also is to be considered. The natural changes in carbohydrate composition that occur during maturation and post harvest ripening of plant foods is therefore of particular interest to food chemists.Citrus fruits, which normally ripen on the tree and contain no starch, undergo little change in carbohydrate composition following harvest. However, in fruits that are picked before complete ripening (eg. apple, bananas, pears), much of the stored starch is converted to sugars as ripening proceeds. The reducing sugar content of potatoes also increases during cold storage. According to the activity of endogenous invertase during the sun drying of grapes and dates, sucrose is converted to D-glucose and D-fructose; accordingly, the color of the dried products is deepened by nonenzymic browning reactions.Greens peas, green beans, and sweet corn are picked before maturity to obtain succulent texture and sweetness. Later the sugars would be converted to polysaccharides, water would be lost, and tough textures would develop. In soybeans, which are allowed to mature completely before harvest, the starch reserve is depleted as sucrose and galactosy lsucroses(raffinose, stachyose, verbascose , etc. ) are formed. In the malting of cereal grains, rapid conversions of reserve carbohydrate to sugars occur as enzymes are strongly activated.In foods of animal origin, postmortem activity of enzymes must be considered when carbohydrate composition data is obtained. The glycogen of animal tissues, especially liver, is rapidly depolymerized to D-glucose after slaughter, and immediate deep freezing is required to preserve the glycogen. Mammalian internal organs, such as liver, kidney, and brains, also eggs and shellfish, provide small amount of D-glucose in the diet. Red fresh meats contain only traces of available carbohydrate (D-glucose, D-fructose, and D-ribose) and these are extracted into bouillons and broths. Dairy products provide the main source of mammalian carbohydrate. Whole cow,s milk contains about 4.9% carbohydrate and dried skim milk contains over 50% lactose.Examination of food composition tables shows that, in general, cereals are highest in starch content and lowest in sugars. Fruits are highests in free sugars and lowest in starch. On a dry basis, the edible portions of fruits usually contain 80-90% carbohydrate. Legumes occupy intermediate positions with regard to starch and are high in unavailable carbohydrate.Words and Expressionscarbohydrate (n.) 碳水化合物polyhydroxy (a.) 多羟基的aldehyde (n.) 醛Carbohydratesketone (n.) 酮hydrolyze (v.) 水解hydrolysis (n.) 水解hydrolysate (n.) 水解产物saccharide (n.) 糖monosaccharide (n.) 单糖oligosaccharide (n.) 寡糖polysaccharide (n.) 多糖hexose (n.) 己糖aldose (n.) 醛糖ketose (n.) 酮糖glucose (n.) 葡萄糖arabinose (n.) 阿拉伯糖galactose (n.) 半乳糖mannose (n.) 甘露糖ribose (n.) 核糖fructose (n.) 果糖refine（v.）精制crystalline (n.) 结晶syrup (n.) 糖浆enzymztic（a.）酶作用的sucrose (n.) 蔗糖beet (n.) 甜菜cane (n.) 甘蔗lactose (n.) 乳糖maltose (n.) 麦芽糖cellobiose (n.) 纤维二糖raffinose (n.) 棉子糖mollasses (n.) 糖蜜sugar-refining（a.）糖的精制whey (n.) 乳请curd (n./v.) 凝乳；凝结casein (n.) 酪蛋白butter fat 乳脂deproteinize (v.) 去除蛋白质deproteinized whey 脱蛋白乳请nonreducing（a.）非还原性的starch (n.) 淀粉glycogen (n.) 糖原cellulose (n.) 纤维素cassava (n.) 木薯microbial strain 微生物菌株catabolite repression 分解代谢抑制A.niger黑曲霉glucoamylase (n.) 糖化酶amyloglucosidase (n.) 淀粉葡糖糖苷酶thermostable (a.) 耐热的amylase (n.) 淀粉酶dextrin (n.) 糊精link（n.）键slurry (n.) 浆gelatinize (v.) 糊化，使成胶状saccharification (n.) 糖化medium (n.) 培养基dietician (n.) 营养学家composition (n.) 组成，成分reducing sugar 还原糖dehydrate (v.) 脱水nonenzymic browning 非酶褐变post harvest 采后ripen (v.) 成熟pear (n.) 梨endogenous (a.) 内源的invertase (n.) 转化酶，蔗糖酶date (n.) 海枣pea (n.) 豌豆green bean (n.) 青刀豆soybean (n.) 大豆galactosy lsucrose (n.) 类半乳蔗糖stachyose (n.) 水苏糖verbascose (n.) 毛葱化糖postmortem (a.) 屠宰后depolymerize (v.) 分解mammalian (a./n.) 哺乳动物（的）（mammal 哺乳动物）extract (v.) 萃取bouillon (n.) 肉汁broth (n.) 肉汤dairy product 奶制品skim milk 脱脂牛奶cereal (n.) 谷物legume (n.) 豆类Chapter 3. Amino Acids and ProteinsProteins are molecules of great size, complexity, and diversity. They are the source of dietary amino acid, both essential and nonessential, that are used for growth, maintenance, and the general wellbeing of man. These macromolecules, characterized by their nitrogen contents, are involved in many vital processes intricately associated with all living matter. In mammals, including man, proteins function as structural components of the body. Muscles and many internal organs are largely composed of proteins. Mineral matter of bone is held together by collagenous protein. Skin, the protective covering of the body, often accounts for about 10% of the total body protein.Some proteins function as biocatalysts (enzymes and hormones) to regulate chemical reactions within the body. Fundamental life processes, such as growth, digestion, and metabolism, excretion, conversion of chemical energy into mechanical work, etc., are controlled by enzymes and hormones. Blood plasma proteins and hemoglobin regulate the osmotic pressure and pH of certain body fluids. Proteins are necessary for immunological reactions. Antibodies, modified plasma globulin proteins, defend against the invasion of foreign substances or microorganisms that can cause various diseases. Food allergies result when certain ingested proteins cause an apparent modification in the defense mechanism. This leads to a variety of painful, and occasionally drastic, conditions in certain individuals.Food shortages exist in many areas of the world, and they are likely to become more acute and widespread as the world,s population increases. Providing adequate supplies of protein poses a much greater problem than providing adequate supplies of either carbohydrate or fat. Proteins not only are more costly to produce than fats or carbohydrates but the daily protein requirement per kilogram of body weight remains constant throughout adult life, whereas the requirement for fats and carbohydrates generally decrease with age.As briefly described above, proteins have diverse biological functions, structures, and properties. Many proteins are susceptible to alteration by a number of rather subtle changes in the immediate environment. Maximum knowledge of the composition, structure, and chemical properties of the raw material, especially proteins, is required if contemporary and future processing of foods is to best meet the needs of mankind. A considerable amount of information is already available, although much of it has been collected by biochemists using a specific food component as a model system.Amino AcidsAmino acids are the ―building blocks‖ of proteins. Therefor e, to understand the properties of proteins, a discussion of the structures and properties of amino acids is required. Amino acids are chemical compounds which contain both basic amino groups and acidic carboxyl groups. Amino acids found in proteins have both the amino and carboxyl groups on the α-carbon atom, α-Amino acids have the following general structure.: NH2R-C-COOHHAt neutral pH values in aqueous solutions both the amino and the carboxyl groups are ionized. The carboxyl group loses a proton and obtains a negative charge, while the amino group gains a proton and hence acquires a positive charge. As a consequence, amino acids possess dipolar characteristics. The dipolar form of amino acids has the following general structure:+NH3R-C-COO-HSeveral properties of amino acids provide evidence for this structure: they are more stable in water than in less polar solvents; when present in crystalline form they melt or decompose at relatively high temperature; and they exhibit large dipole moments and large dielectric constants in neutral aqueous solutions.The R group, or side chains, of amino acids exert important influences on the chemical properties of amino acids and proteins. These side chains may be classified into four groups.Amino acids with polar-uncharged (hydrophilic) R groups can hydrogen-bond with water and are generally soluble in aqueous solutions. The hydroxyls of serine, threonine, and tyrosine; the sulfhydryl or thiol of cysteine; and the amides of asparagine and glutamine are the funcitional moieties present in R groups of this class of amino acids. Two of these, the thiol of cysteine and the hydroxyl of tyrosine, are slightly ionized at pH 7 and can lose a proton much more readily than others in this class. The amides of asparagine and glutamine are readily hydrolyzed by acid or base to aspartic acids and glutamic acids, respectively.Amino acids with nonpolar (hydrophobic) R groups are less soluble in aqueous solvents than amino acids with polar uncharged R groups. Five amino acids with hydrocarbon side chains decrease in polarity as the length of the side chain is increased. The unique structure of proline (and its hydoxylated derivative, hydroproline) causes this amino acid to play a unique role in protein structure.The amino acids with positively charged ( basic ) R groups at pH 6-7 are lysine, arginine, and histidine. The amino is responsible for the positive charge of lysine, while arginine has a positively charged quanidino group. At pH 7.0, 10% of the imidazole groups of histidine molecules are protonated, but more than 50% carry positive charges at pH 6.0.The dicarboxylic amino acids, aspartic and glutamic, possess net negative charges in the neutral pH range. An important artificial meal-flavoring food additive is the monosodium salt of glutamic acid.Protein StructureProteins perform a wide variety of biological functions and since they are composed of hundreds of amino acids, their structures are much more complex than those of peptides.Enzymes are globular proteins produced in living matter for the special purpose of catalyzing vital chemical reactions that otherwise do not occur under physiological conditions. Hemoglobin andmyoglobin are hemo-containing proteins that tranport xoygen and carbon dioxide in the blood and muscles. The major muscle proteins, actin and myosin, convert chemical energy to mechanical work, while proteins in tendons (collagen and elastin) bind muscles to bones. Skin, hair, fingernails, and toenails are proteinaceous protective substances. The food scientist is concerned about proteins in foods since knowledge of protein structure and behavior allows him to more manipulate foods for the benefit of mankind.Nearly an infinite number of proteins could be synthesized from the 21 natural occurring amino acids. however, it has been estimated that only about 2000 different proteins exist in nature. The number is greater than this if one considers the slight variations found in proteins from different species.The linear sequence of amino acids in a protein is referred to as ―primary structure‖. In a few proteins the primary structure has been determined and one protein (ribonuclease) has been synthesized in the lab. It is the unique sequence of amino acids that imparts many of the fundamental properties to different proteins and determines in large measure their secondary and tertiary structures. If the protein contains a considerable number of amino acids with hydrophobic groups, its solubility in aqueous solvents is probably less than that of proteins containing amino acids with many hydrophilic groups.If the primary structure of the protein were not folded, protein molecules would be excessively long and thin. A protein having a molecular weight of 13,000 would be 448 A long and 3.7 A thick. This structure allows excessive interaction with other substance, and it is not found in nature. The three-dimensional manner in which relatively close members of the protein chain are arranged is referred to as ―secondary structure‖. Examples of secondary structure are the α-helix of wool, the pleated-sheet configuration of silk, and the collagen helix.The nature structure of a protein is that structure which possesses the lowest feasible free energy. Therefore, the structure of a protein is not random but somewhat ordered. When the restrictions of the peptide bond are super-imposed on a polyamino acid chain of a globular protein, a right-handed coil, the α-helix, appears to be one of the most ordered and stable structures feasible.Theα-helix contains 3.6 amino acid residues per turn of the protein backbone, with the R groups of the amino acids extending outward from the axis of the helical structure. Hydrogen bonding can occur between the nitrogen of one peptide bond and the oxygen of another peptide bond four residues along the protein chain. Hydrogen bonds are nearly parallel to the axis of the helix, lending strength to the helical structure. Since this arrangement allows each peptide bond to form a hydrogen bond, the stability of the structure is greatly enhanced. The coil of the helix is sufficiently compact and stable that even substances with strong tendencies to participate in hydrogen bonding, such as water, cannot enter the core.A secondary structure found in many fibrous proteins is the β-pleated sheet configuration. In this configuration the peptide backbone forms a zigzag pattern, with the R groups of the amino acids extending above and below the peptide chain. Since all peptide bonds are available for hydrogenbonding, this configuration allows maximum crosslinking between adjacent polypeptide chains and thus good stability. Both parallel pleated sheet, where the polypeptide chains runs in the same direction, and antiparallel pleated sheet, where the polypeptide chains run in opposite directions, are possible. Where R groups are bulky or have like charges, the interactions of the R groups do not allow the pleated-sheet configuration to exist. Silk and insect fibers are the best examples of theβ-sheet, although feathers of birds contain a complicated form of this configuration.Another type of secondary structure of fibrous proteins is the collagen helix. Collagen is the most abundant protein in higher vertebrates, accounting for one third of the total body protein. Collagen resists stretching, is the major component of tendons, and contains one-third glycine and one-fourth proline or hydroxyproline. The rigid R groups, and the lack of hydrogen bonding by peptide linkages involving proline and hydroxyproline, prevents formation of anα-helical structure and forces the collagen polypeptide chain into an odd kinked-type helix. Peptide bonds composed of glycine form interchain hydrogen bonds with two other collagen polypeptide chains, and this results in a stable triple helix. This triple-helical structure is called ― tropocollagen‖ and it has a molecular weight of 300,000 daltons.The manner in which large portions of the protein chain are arranged is referred to as tertiary structure. This involves folding of regular units of the secondary structure as well as the structuring of areas of the peptide chain that are devoid of secondary structure. For example, some proteins contain areas whereα-helical structure exists and other areas where this structure cannot form. Depending on the amino acid sequence, the length of theα-helical portion varies and imparts a unique tertiary structure. Those folded portions are held together by hydrogen bonds formed between R groups, by salt linkages, by hydrophobic interactions, and by covalent disulfide (-S-S-) linkages.The structures discussed so far have involved only a single peptide chain. The structure formed when individual (subunit) polypeptide chains interact to form a native protein molecule is referred to as ―quaternary structure‖. The bonding mechanisms that hold protein chains together are generally the same as those involved in tertiary structure, with the possible exception that disulfide bonds do not assist in maintaining the quaternary structures of proteins.Properties and Reactions of ProteinThe primary, secondary, and tertiary structure of proteins affect both how the proteins react in the preparation and processing of foods and how they are affected by the various treatments involved in food preparation.The amphoteric property of proteinsProteins are amphoteric---- they have both acidic and basic characteristics because they can exist as hybrid ions, or zwitter ions. The ionizable hydrogen ion can transfer from the acidic carboxyl group to the basic amino group. If the amino acid glycine is used to represent a protein, then the zwitter ion would be formed as follows:H H OH H H O-H—N—-C—C=O ↔ H—N—-C—C=O+If a hygrogen ion is added to the zwitter ion, it adds on to the carboxyl group as shown below:H H O-H H OHH—N—-C—C=O ↔H—N—-C—C=OH+H H+ HIf a hydroxyl ion is added to the zwitter ion, it removes the hydrogen ion from the amino group to form a molecule of water, as shown below:H H O-H H O-H—N—-C—C=O + OH- ↔H—N—-C—C=O + H2OH+H HThus, proteins can act as buffers because the addition of acid or base does not change the pH of the protein until all of the carboxyl or amino groups are undissociated depending on whether acid or base is added.Fresh milk, for instance, is pH 6.6, and the casein protein carries a net negative charge; that is, there are more ionized carboxyl groups on the protein than ionized amino groups. If acid (H+) is added to milk, no visible change occurs initially with small additions of hydrogen ion, but when the pH reaches 5.2, the milk curdles. At the isoelectric point, pH4.6, the milk protein casein has equal numbers of positive and negtive charges. The pH of the isoelectric point differs for each protein depending on the ratio of the free carboxyl to free amino groups in the protein.the Water-Binding Capacity of ProteinAnother property of proteins that contributes to their ability to form colloidal dispersions is their attraction for water. Molecules of water bind to both the backbone and the polar R groups of protein. These water molecules form a layer of water molecules around the protein molecules and contribute to maintaining the stability of a colloidal dispersion because the water molecules all carry the same charge, and this causes the hydrated protein molecules to repel each other and to remain dispersed,. Proteins vary in the number of sites on the protein molecule that will permit the bonding of water.Proteins that bind water readily are said to be hydrated; an example is ovalbumin, a protein in egg white. Casein is less readily hydrated; it does not bind water readily. Both the layers of water molecules bound to the surface of the protein and the repulsion between the like charges on the protein molecules aid in keeping the protein dispersed and in contributing stability to the colloidal dispersion. Denaturation of ProteinsDenaturation has been defined as a disordered arrangement of the structure of the protein molecule.。
食品英文文献带翻译
In addition to these themes, food literature also examines the politics of food, the ethics of eating, and the sensory experience of food. For instance, the essay collection “The Gastronomical Me” by M.F.K. Fisher delves into the cultural and social implications of different food rituals and traditions around the world. Fisher’s lyrical prose and insightful observations offer readers a deeper understanding of how food shapes our daily lives and our sense of belonging.
食品科学专业英语翻译
1.Alcoholic beverages are produced from a range of raw materials but especially from cereals,fruits and sugar crops .They include non-distilled beverages such as beers,wines,ciders,and sake.Distilled beverages such as whisky and rum are produced from fermented cereals and molasses,respectively,while brandy is produced by distillation of wine.Other distilled beverages,such as vodka and gin,are produced from neutral spirits obtained by distillation of fermented molasses,grain,potato or whey.A variety of fortified wines are produced by addition of distilled spirit to wines to raise the alcohol content to 15-20%.Notable products include sherries,Port and Madeira wines.含酒精的饮料是由一系列的原料,尤其是由谷物,水果和糖作物包括non-distilled钪的饮料,如:啤酒、葡萄酒、杯苹果酒,酒的。
如威士忌蒸馏饮料、朗姆酒制造谷物和糖蜜发酵,分别站在白兰地是由蒸馏的酒。
其他蒸馏饮料,如伏特加和杜松子酒,制造了中性酒精蒸馏发酵糖蜜,谷物,马铃薯或乳清。
食品专业毕业论文外文翻译5
外文文献：Prefab Cold StoresPart One Technology OverviewThe industrialization of agriculture has speeded deep-processing for agricultural products, finely processing for food, and the development of freeze and deepfreeze technology, and has demanded of further cold stores in tonnage, in scale, and in modes. Thus, new cold stores for food processing and storing are born with the advance of science and technology and refrigeration. The new cold stores have substituted for the traditional ones in constructions and operations, through bran-new construction ideas, i.e. of standardization, of modularization, and of industrialization, etc. Prefab cold stores, increasingly widening their application scopes, and expanding their construction scales, is representing the leading developmental trend of refreeze and deepfreeze, endowed with brilliance of future. DBGC, the domestic largest manufacturer for refrigeration equipment, has first introduced the technology of advanced prefab cold stores, and has drafted out the national standard for prefab cold stores. DBGC has undertaken for clients such complete technology of prefab cold stores as elaborations for technology programs designs for cold stores, refrigeration equipment, shield structure, stores heat preservations, electrical controls, installations, and executions for trials. Just within 3 months, DBGC can complete and present client with a satisfactory project of prefab cold store which includes designs and installations for cold store. “Bingshan” prefab cold sto re is up to the requirements of exports transited in cold stores to European Union and Japan, enabling clients’ certifications from European Union and Japan to be granted easily. Now DBGC can offer prefab cold store from 10m3 to 20000 m3 in capacity，from 5 tons to 50000 tons in tonnage volume, all will be met special requirements of clients, and flexibly scientific in designing and manufacturing. At present, DBGC is undertaking prefab cold stores projects worldwide.Part Two Technology ProgramThe prefab cold store consists of shield structure，and prefab thermal insulting board, etc, the thermal insulting board is on both sides paneled with color steel plate, aluminum plate andstainless steel plate，with the core thermal insulting materials of generally ester urethane or polystyrene, etc，whose weight is 5%~10% light compared with other construction materials, and with the shield structure of light steel. Depending on the combination of thermal insulting materials with shield structure, there are external frame structure and internal no-frame structure for prefab cold stores. At present, the external structure prefab cold store is often used. 1st, Store Boards Store board type: hardiness ester-urethane thermal-insulting board and poly-benzene heat preservation board. Now internationally, the hardiness ester-urethane thermal-insulting board with satisfactory heat transmit coefficient is generally used. This board is of polyester filmed color steel plate both externally and internally; with new convexity and concave groove structure of convenient installation，and with fine heat preservation of property. The store board, completely produced by the advanced production line exported from Italia, has met the international standard for all technical data. ⑴connection modes：①inlay connections、②PVC connections、③H-type aluminum connections、④pothook connections ⑵technical data of ester urethane board2nd, Refrigeration Technology To satisfy its requirements for refrigeration in tonnage and for food technology, the cold stores have applied ammonia cooling system, freon cooling system and indirect glycol cooling system, etc. The ammonia system：the refrigeration medium is ammonia(R717)，through liquid ammonia the heat is carried away to satisfy freeze and deepfreeze temperature for food; the freon system: the refrigeration medium is freon (R22、R134a、R404a), the system is highly automatic and quite applicable for small prefab cold stores; the glycol system: fully automatic, simply and conveniently controlling, the system fulfill heat exchanges through narrow temperature gap in liquid glycol，which may reduce food loss for drying, and quite suits air-conditioned preservations for fruits and vegetables. 3rd, Refrigeration Equipment DBGC manufactures “Bingshan” screw refrigera tion compressors, reciprocating refrigeration compressors and semi-hermetic refrigeration compressors. Superior in quality and excellent in services, DBGC can offer you a wide range of “Bingshan” refrigeration compressors combinations worldwide, and provides you with top quality refrigeration equipment of effective energy-saving and high ratio of performance and price. 4th, Electric Controls For “Bingshan” prefab cold stores, both manual operations and automatic controls are available. The automatic controls has risen to international advanced level in such fields as running and load and unload of refrigeration equipment, temperature of cold stores and refrigeration medium, dynamic stimulation for equipment running, printing and recording of running parameters，supplies for liquid, melting of frost，accidents alarm and its analysis, and condensation pressure, almost all controls for cold stores are executed under on duties of operators. 5th, Food Technology Wide ranges of processing technologies for food are acquired by DBGC, for example, processing, freeze and deepfreeze, storage and preservation, etc. It is the ultimate ends that DBGC tries to best design refrigeration programs for clients in consideration of both food technology and refrigeration technology.Part Three Technology Framework1st, Steel structure 2nd, Store and ground heat preservation 3rd, Moisture-proof and vapor-proof 4th, Refrigeration equipment (ammonia system、fluorin system and glycol system, etc）5th, Equipment for damping store inside 6th, Equipment for rinsing frost and water-cooling 7th,Equipment for electrical controls 8th, Equipment for ventilation 9th, Other equipment（for cold store doors、security controls、shield structure and auxiliary parts）Part Four Technology Feature1st, Good appearance: over ten colors are selective for thermal-insulting board and supporting shield structure, at satisfactory options to any styles of buildings. 2nd, Heat preservation：ester-urethane thermal-insulting board and poly-benzene heat preservation board are lower in heat transmit coefficient，strong in material strength，and fine for heat preservations. 3rd, Flexible design：all specifications of thermal-insulting board for cold stores come up to constructional requirement modes, and flexibly satisfy cli ents’ needs for partitions and collations for cold stores. 4th, Short construction period 5th, Fast installation 6th, Sanitary and tidy store conditions inside for food 7th, Durable constructional structure 8th, Topping materials used 9th, Exact controls for temperaturePart Five Technical Datavolume classification chart store heat transmit coefficient chart store temperature classification chart store temperature indoor asymmetry chart empty store temperature drop timetable.Part Six Construction Flow1st, Earth projects executions for heat preservation layer under level ground, and constructionsfor power workshops and pump workshops. 2nd, installations and constructions for steel structures or supportive shield structures，equipment for power and pump workshops are ready for running. 3rd, Framework constructions for cold stores 4th, Executions of earth projects under level ground (ground、heat preservation layer、water-proof and vapor-proof layer, etc）and constructions for structure above level ground. 5th,Installations for store doors、air curtains、door shades、refrigeration equipment、eclectic control system、water-supply system of rinsing frost、and store framework, etc 6th, Installations for bump-avoided structure, etc 7th, Coating airtightconstructions for stores both indoor and outdoor 8th, Debugging and trials for all systems of cold stores 9th, Examinations and acceptances for coldPart Seven Technology Scope1.Freeze and deepfreeze for food（aquatic products、poultry、birds、proceeded food、vegetables, fruits）2.Packinghouse (pig、cattle、sheep、chicken、duck、goose）3.Food processing manufactory4.Indoor assembly cold stores5.Seeds stores6.Biological and medical products1.7.Dairy products storage中文译文：组合式冷库一、概况农业工业化促进了农产品的深加工，食品精加工和冷冻速冻技术的发展，并对冷库的吨位，级别，型号提出了新的要求，伴着先进的科技及冷藏技术，适用于食品加工及贮藏的新型冷库应运而生。
食品科学与工程外文参考文献译文及原文
本科毕业设计（论文）外文参考文献译文及原文学院轻工化工学院专业食品科学与工程年级班别2006级（2）班学号3106002145学生姓名龚张卫指导教师姜燕2010 年 6 月目录1. 介绍 (1)2. 材料与方法 (1)2.1 原料 (2)2.1.1市售猕猴桃果酱/果酱 (2)2.1.2水果............................................................ .......... (2)2.1.3渗透溶液............................................. (2)2.1.4胶凝剂 (3)2.1.5酸度调节剂 (3)2.2猕猴桃果酱/橙果酱详细制作过程 (3)2.2.1传统制作过程 (3)2.2.2渗透失水水果制作过程 (3)2.3分析 (3)2.3.1理化性质 (3)2.3.2 色泽测量......... ...... ...... ...................... . ...... . (3)2.3.3 流动性能......................................... ... ............................ . (4)3. 结果和讨论 (4)结论 (9)参考资料 (9)渗透脱水水果制作果酱的研究E. García-Martínez, G. Ruiz-Diaz, J. Martínez-Monzó, M. M. Camacho, N.Martínez-Navarrete and A. Chiralt瓦伦西亚大学食品技术系，巴伦西亚，46071摘要：果酱是由水果和糖按比例混合制得的产品，最终产品含有最小30％果肉成分和最低45糖度值。
传统果酱制作需要通过热处理来浓缩加工，从改变感官和营养特性提高产品质量，营养特性的改变主要是果酱中抗坏血酸损耗量的多少。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
基于对海栖热孢菌来源的α-L-阿拉伯呋喃糖苷酶的结构分析揭
示其热稳定性和底物特异性特征
从海栖热孢菌MSB8中提取的α-L-阿拉伯呋喃糖苷酶(TmAFase)是一种高耐热性半纤维素外切酶,与其他51糖苷水解酶家族的酶相比较，作用于阿拉伯糖和木聚糖时显示出了相对较高的活性。
在目前的研究中，我们完成了关于阿拉伯糖苷酶的酶动力学特性和结构分析的工作。
在海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）中发现的紧密领域协同作用,比如在每一个单体上的一个域间二硫键(Cys306和Cys476),在二聚物的界面上的一个新的延伸臂(氨基酸374-385),和六聚体上的所有12个盐桥,应该是酶的热稳定性的原因。
木聚糖聚合力的决定因素之一(Trp96)被确认是在活性部位,一定范围的氨基酸(374 - 385)突出隆起在底物结合位点生成一个凹点并形成一个明显的墙层来。
蚀变性的小洞形状，带有一个强大的负静电分布，可能与海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）的支化聚合物基质与独特的结构衬底有关。
关键词：海栖热孢菌阿拉伯糖苷酶结构分析X-衍射结晶学
半纤维素是由各种戊糖糖、己糖糖,糖和酸组成的最丰富、可再生多相聚合物之一。
最近,研究人员正高度关注在半纤维素等各种可发酵糖的高效分解，生物燃料和化学品的生产方面。
由于半纤维素生物质在结构上极高的复杂性和可变性,因而,几个半纤维素酶的协同作用主要包括裂解开链外切-β-(1,4)木聚糖酶和β-xylosidases和侧面消除开链辅助酶,对这些生物质材料的完全降解至关重要。
α-L-阿拉伯
呋喃糖苷酶(AFase; E.C. 3.2.1.55)是最重要的辅助酶,这种酶可以催化水解的终端那些非还原性的α-L -(1、2),α-L -(1,3),和α-L -(1、5)-arabinofuranosyl 残留物来源于arabinose-containing多糖,如阿拉伯多糖和阿糖基木聚糖。
当作用于高分子聚合物时，这些酶与半纤维素酶结合可以协同性加快糖苷键的水解作用。
阿拉伯呋喃糖苷酶(AFase)主要属于糖苷水解酶(GH)家族51和54[1,6]。
在过去的几十年，AFases重要组成部分的结构功能关系已经在许多研究中得出了。
自从Hövel et al.[8]从嗜热脂肪土芽孢杆菌T-6中确定阿拉伯呋喃糖苷酶（AFase）的三维结构，微生物来源的AFases 结构已经在梭状芽胞杆菌thermocellum ATCC 27405 [22]和热杆菌属木聚糖的研究中被报道过了。
在目前的研究中,我们使用固定大肠杆菌表达的重组海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）并确定其三维结构。
后来，这个结构被用于与其他GH-51家族酶相比较，以更好地了解其在功能方面的高耐热性和独特的底物特异性。
材料和方法
基因表达与酶纯化
酶活性测定
结晶和数据收集
结构测定与数据收集
结果与讨论
阿拉伯糖苷酶的酶特征
在此之前，我们从海栖热孢菌MSB8和杆菌属KCTC 3012中克隆了海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）和阿拉伯木聚糖苷酶（GAFase）的基因，并且让它们分别在大肠杆菌中进行异源性表达。
虽然阿拉伯糖苷酶与阿拉伯木聚糖苷酶在氨基酸序列上只有36%的一致性，但是它属于GH 51家族中典型的外部作用酶，在裂解阿拉伯多糖末端残基中的非还原性的多个分支，包括α-L-(1,2)-，α-L-(1,3)-和α-L-(1,5) 阿拉伯糖，然而，它们的最佳反应温度和底物专一性彼此间完全不同。
实验中显示出，海栖热孢菌属的阿拉伯糖苷酶的最适温度显示在80℃以上（在pH在4.5的情况下），100℃时它的热稳定性半衰期为235分钟，然而阿拉伯木聚糖苷酶（GAFase）的最佳温度在60℃（在pH 6.0的情况下）。
基于图表1中所显示，高度耐热的海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）在阿拉伯木聚糖苷酶（GAFase）中很容易被辨识区分出来。
海栖热孢菌来源的阿拉伯呋喃糖苷酶（TmAFase）作用于多种聚合物基底时与GAFase相比而言，有着相对更高的反应活性。
在聚合物基底中，甜菜的分支中的阿拉伯糖是海栖热孢菌来源阿拉伯呋喃糖苷酶最适宜的底物，然而主干中的阿拉伯糖更适合木聚糖阿拉伯糖苷酶。
事实上，相对于GAFase(0.16 U/mg)极其低的活性，海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）(3.34 U/mg)对燕麦木聚糖（一种阿拉伯木聚糖）有相当好的水解作用。
与GAFase相比，有着较高的最适温度的海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）很可能在聚合物底物的酶解反应中提供相对更高的能
量。
此外，海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）适用于木聚糖的水解，对阿拉伯木聚糖也有更好的侧枝剪切力。
阿拉伯木聚糖是半纤维素中的重要部分之一，在具有较高的酶活性的酶类中，热稳定好这一点能满足从半纤维素生物质中提取珍贵戊糖等成分的
需要。
结晶化与结构测定
结构良好的晶体（具有代表性的，并且有着明显清晰表面的矩形板形状）在四天后可以被检测到。
具有典型性的尺寸大小，可以成长到0.2*0.5mm左右的晶体。
光衍射模式下，可以看出一个单斜的晶体晶胞，晶体参数为a = 103.710, b = 161.538, c = 112.602 Å, β= 106.301。
就目前如我们所知，在一个不对称的结晶性分子晶体单体结构中，通常有六个分子。
海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）的晶体分子(PDB code; 4ATW)结构，在3.0 Å分辨率下，使用分子置换法（MR），以分子结构最接近的作为参照（36%的序列同源性）并进行计算和测评。
实验要求通过麦休斯系数来计算达到2.73 Å3 Da-1，溶剂用量在CCP4i组合的读数表软件中得到54.97%的结果。
根据中国国家标准CNS来进行初步操作的细化和分类，利用极大似然估计法在目标范围内进行分析。
实验中的模型，进行了刚性体结构的细化和分析，还有模拟退火算法，在定位参数的周期循环中反复提炼迭代优化。
在使用的Coot程序中，组建蛋白质模型的操作要求，每一个精良制作的圆形物在循环中总是后面紧跟着手工制作的装置备件。
最终操作中，这个精制所得到的模型，将会会聚得到22.999%
的以R末端结尾的终点要素和25.544%的R free末端结尾的终点要素。
极其具有代表性，并且可以明显观察到的是在表2中所列出的细化模型数据和最终完成的整体模型数据。
在表中，可以观察得出海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）在结构和模型中所具有的明显优于其他阿拉伯糖苷酶的晶体结构。
阿拉伯糖苷酶的整体架构
海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）中的非对称单体包括对称面上的三倍非结晶体和垂直面上的两倍对称体。
研究发现，每一个精确度较高的单分子构造的组成与其他的GH-51家族的酶类都十分相似，其中最主要的酶类就包括热孢菌来源的阿拉伯糖苷酶[8,9,14,21]，也就是由两个结构域——起催化作用的N末端结构域和起串联作用的C末端夹入结构域共同构成的。
这其中，从其他糖基水解酶的方面来观察，起着催化作用的枪管（β/α）8领域有着非常典型的椭圆形截面，C末端上与碳水化合物粘合类部分的模块有着极其相似的结构化支架，也就是CMB6和CMB9，并且显示出与高分子碳水化合物在粘合过程中所具有的较强功能性、多样性和复杂的参与能力。
在海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）功能化结构单体中，大多的结构域和结构域之间的相互作用呈现出更强的变化趋势，分析其原因，主要在于受到分子内部的二硫键残基上的半胱氨酸306和半胱氨酸476的影响。
这个二硫键，是分子内部中的多个枪管结构域的一个螺旋线上的架桥结构，起着连接的作用，并且处于两
个结构域之间，疏水相互作用的中心部分。
在分子中可以观察到，从活性区域的活性位点，也就是循环区域中的氨基酸374-384范围的额外拓展出的相互作用，大多被增补到这个联合结构域中。
这个很容易被辨识出的环状位点，只在海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase）中被发现，进一步的观察中，发现它起源于C末端并沿着环形链状，环绕着催化区域。
在聚合物复合体中，一共存在着6个二硫键，这一点也许就是导致海栖热孢菌就来源的阿拉伯呋喃糖苷酶（TmAFase），具有较好的热稳定性的多个原因之一，也是相对十分重要的原因，同时，实验中表明，在其他许多的阿拉伯糖苷酶晶体结构中，没有观察到两个结构，分别是跨域间二硫键和延伸出的环状结构。
活性部位的描述
二聚物界面上的相互作用
负电荷分布连通槽
致谢
参考文献。