1、食品专业英语食品专业英语（一）(2010-04-30 13:59:25) 转载Lesson 17 CEREALSThe word “cereal” derives from the name of the Roman grain or harvest goddess, Ceres (usually depicted with ears of barley braided in her hair).Cereals are the seeds of grasses. The plants from which cereals come are wheat, rice, corn, rye, oat
2、s, and barley. A limited quantity of wild rice, Zizania aquatica, is marketed in the Unlike States. It is a cereal and more like barley than like ordinary rice. Unlike the other cereals which evolved in nature, triticale, a wheat-rye hybrid, was crossed intentionally. Cereal products made from grain
3、 include breakfast foods, rice, flours, and macaroni products.第17课 谷 物“谷物”这个词来源于罗马谷物女神即收获女神的名字色列斯（Ceres）（常常用编在她头发上的大麦穗来描摹）。谷物是禾本植物的种子。产谷物的植物有小麦、稻、玉米、黑麦、燕麦和大麦。数量有限的野生稻米水菰在美国市场上有销售。它是一种谷物，与大麦、普通稻谷相比，更像大麦。黑小麦是小麦与黑麦的杂交种，它不像其它自然界中演化出来的谷物，而是有目的地进行过杂交的。由谷粒制成的谷物制品有：早餐食品、米、面粉和通心粉制品。Consumption of CerealFor h
4、uman consumption, wheat is the main cereal in the United States and Canada; rice the main cereal in China, Japan, and India; rye the chief one in Russia and in central Europe. Corn is used in Mexico, South America, and the United States. Oats are used to a limited extend for human food.就人们的消费来说，小麦是美
5、国和加拿大的主要谷物，稻米是中国、日本和印度的主要谷物，黑麦是苏联和中欧的主要谷物。玉米的消费在墨西哥、南美和美国。燕麦用作人类的食物数量有限。Not only does the main cereal consumed vary from country to country but so does the importance of cereals as a whole in the diet. The proportion of total calories which comes from cereals is low in United States（21 percent），in c
6、ontrast to parts of the Far East where the proportion is much higher. The reason for these extremes is that in the United States the resources (land, climate, money, machinery, and agricultural know-how) for the production of food in relation to the number of people to be fed are high; in the Far Ea
7、st they are low. Where the food supply is inadequate for the population, grains must be eaten to prevent starvation. Fruit and vegetables do not begin to approximate the calories contained in cereals from the same amount of land and labor. Furthermore, to produce milk, eggs, and meat, primary agricu
8、ltural products are fed to animals, which convert them into a more desirable form, but in the process waste much potential food for human beings.不仅消费的主要谷物各国之间不相同，而且从总体上来看，各种谷物在膳食中的重要性各国之间也有差异。在美国，人体所需的总热值中来自谷物所占的比率低（21%），而在部分远东地区这一比率则相当高。出现这两种极端情况的原因是，在美国，生产食物的资源（土地、气候、资金、机械和农业技术）相对于需要供应食物的人口来说很丰富。而
9、在远东，相对于人口的资源很不足。在食物供应与人口相比不足的地区，为了避免饥饿必须食用谷物。水果和蔬菜绝对做不到与来自等量土地、劳力的谷物中所含有的热量（卡）想接近。此外，如果要生产乳、蛋和肉类，就得给动物喂饲初级农产品，而动物将农产品转化为更合乎要求的形式，但在这一过程中动物消耗掉大量人类潜在的食物。 The estimated yield from 10 acres of land devoted to growing cattle is enough beef ( in pounds ) to feed one individual for one year .But the 10 acr
10、es of land could be used to produce enough wheat to feed 15 people for a year or enough rice to feed 24 .The corn plant is an especially valuable food producer .It is one of the most efficient trappers of the suns energy , sugar cane being another .Of course ,filling an individual is the sole functi
11、on of food , But when one is hungry, getting enough food is an immediate objective.10英亩专用于养牛的土地，预计它所产的牛肉（磅）足供一人一年食用。但是，这10英亩土地也可设想用来生产很多小麦，足供15人吃一年，或很多大米足供24人吃一年。玉米作物是一种特别有价值的食物制造者。它是最有效的太阳能吸收物之一。糖甘蔗是另一种这样的植物。当然，填饱肚子不是食物的唯一功能。但当人们饥饿时，吃饱则是眼前的目的。Cereals provide almost half (47 percent) of the dietary
12、protein worldwide, and they could make a greater contribution. Each hectare (2.47 acres) of corn planted in the United States will yield enough utilizable protein to feed 12 people 60 grams of protein per day for one year. For t rice he figure is 10 and for wheat 8. True, cereals do not compare with
13、 animal foods for either quantity quality of protein. Cereals are especially deficient in the essential amino acid lysine. Even so, yields of both protein an of essential amino acids per acre of cultivated land are several times greater from the seed is used directly as food rather than from animals
14、 fed the same amount of corn. Calculated yield of protein from corn is 234 pounds per acre, and of essential amino acids 80 pounds per acre. Were this corn fed to animals, calculated yields of protein in pounds per acre are 87 for milk,82 for broilersw,60 for eggs,56 for hogs,49 for chickens, and 26
15、 for beef. Yields of essential amino acids in pounds per acre range from 37 for milk to 10 for beef. Interestingly, the yield of protein which can be extracted from the leaves of green corn is at least as great as that from the mature seed.谷物在世界范围内提供了几乎一半（47%）的膳食蛋白质，而且还可能有更大的贡献。在美国，每公顷（2.47英亩）种植的玉米，
16、一年可以生产出足够给12人每天吃60g的可利用蛋白质。对于稻米，这个数字是10人，小麦是8人。的确，谷物无论就蛋白质的数量还是质量而言，都不能与动物性食物相比。谷物特别缺乏必需氨基酸赖氨酸。即使如此，在直接把玉米当食物用时，每英亩耕地所获得的蛋白质产率和必需氨基酸产率两者都比来自用同量玉米喂饲的动物的产率要高出好几倍。每英亩的玉米蛋白质计算产率为234磅，必需氨基酸计算产率是80磅。如果将这些玉米喂养动物，那么计算的蛋白质产率以磅/英亩计，乳中为87磅、肉鸡中为82磅、蛋中为60磅、猪中为56磅、鸡中为49磅、牛肉中为26磅。每亩的必需氨基酸产率以磅计的范围从乳中的37磅到牛肉中的10磅。有趣
17、的是，能够从嫩玉米的叶子中提取出来的蛋白质产率至少同来自成熟玉米粒的蛋白质产率一样。The utilization of cereals has declined in the United States. The consumption of wheat forecast for 1979 was 112 pounds per capita, three-fourths of it as flour and most of that white flour. This compares with an annual per capita consumption of 309 pounds 6
18、0 years ago. A number of things have contributed to this change in our food pattern. Refrigeration makes available fresh, perishable foods the year around and eliminates dependence upon nonperishable cereals for a large part of the winters food supply. Too, people have more money and with a high sta
19、ndard of living shift from economy foods such as cereals and potatoes to more expensive ones. Another possible reason for shift from cereals is that many people do not lead such active lives as in previous times and so do not need as much energy. For example providing butter for the family table in
20、many homes 50 years ago necessitated first milking the cow, straining the milk, cooling the milk, separating the cream, churning it, carrying the butter to the spring or a milk house to keep it cool, and finally making a trip for it just before the meal. Today, providing butter involves a trip in a
21、automobile to the nearest supermarket, lifting the parchment-wrapped sticks from the refrigerator, and driving home, where the butter is placed in a refrigerator until mealtime. Too, the current emphasis on slenderness may have some bearing on the decrease in the use of grain for human food. Such st
22、archy foods as cereals and breads as well as potatoes are considered fattening. None of these is inherently fattening. The sugar, cream, butter, and other fats eaten with such foods or combined with them in recipes often contribute more calories than the cereals or potatoes themselves.在美国，对谷物的利用已经减少
23、。预测1979年的小麦消费量为每人112磅，其中84是以面粉的形式消费的，并且大部分为白面粉。相比之下，60年以前的人均小麦的年消费量309磅。我们食物结构的这种变化是有若干因素引起的。冷藏使人们全年可以获得新鲜的，易腐烂的食物，从而对对冬季的大部分食物供应不需要依赖不易腐烂的谷物。此外，人们有了更多的金钱，加上生活水平的提高，就逐渐从谷物，土豆之类的经济食物转向比较昂贵的食物。从谷物转向的另一个可能原因是许多人不想从前那样过着费力的生活，所以也就不需要那么的能量。例如，50年前，许多家庭中，用餐准备黄油，首先需要挤乳，过滤牛奶，冷却牛乳，分离出稀奶油，搅拌稀奶油，送黄油到冷藏所或奶场冷藏,最
24、后在就餐前不久,还要往返跑一趟,今天准备黄油只需要用汽车到附近超市去一趟,从冷藏柜里拿出几块用羊皮纸包装的黄油,然后驱车回家.另外,近来对身材苗条的看重可能对谷物用于人类食物的减少产生一定的影响.像谷物，面包以及土豆一类淀粉质食物被认为是增肥性的。这些食物任何一种都不是原本就使人发胖的。与这类食物一起吃下去的或配方中与这类食物混在一起的糖，稀奶油，黄油及其它脂肪常常比谷物或土豆本身提供的卡路里还要多。Composition of CerealsCereals as a group are a approximately 75 percent carbohydrates, 10 percent
25、protein, 1 to 2 percent fat, 10 percent moisture ,and 1 to 2 percent ash. The main carbohydrate in cereals is starch. A second carbohydrate is cellulose. Cereals contain protein of a quality somewhat lower than that found in animal foods such as meat, milk, and eggs. Cereals as a group are deficient
26、 in lysine，and low in tryptophan and methionine .The level of these essential amino acids can be increased in cereals by the introduction of certain mutant genes. High lysine corn was developed some years ago. Two genes enable the corn plant to synthesize more lysine and also more tryptophan than th
27、e typical hybrid corn. Genes are available for improving the quality of the proteins in rice, barley, and wheat, too. Unfortunately, this genetic engineering which results in a higher lysine content also may result in lower total protein and lower yield. Functional properties of the cereal in food p
28、reparation are altered, too. The liming of corn in the preparation of such foods as tortillas paradoxically decreases a number of nutrients in the corn, at the same time improving its overall nutritive value by producing a better balance of amino acids. Triticale, the rye-wheat hybrid, is higher tha
29、n wheat in lysine and in protein but the yield per acre is lower.谷物的组成作为整个一类的谷物约含75%碳水化合物、10%蛋白质、12%脂肪、10%水分和12%灰分。谷物中的主要碳水化合物是淀粉。第二种碳水化合物是纤维素。谷物中含有的蛋白质的质量稍次于肉、乳、蛋等动物性食物中存有的蛋白质总量。谷物就总的一类来说，缺乏赖氨酸，色氨酸，蛋氨酸也很少，谷物中这些必需氨基酸的含量可以通过导入某些突变基因加以提高。若干年以前曾培育了高赖氨酸玉米。有两种基因使玉米植株能够合成比典型杂交玉米更多的赖氨酸和色氨酸。也有一些基因可以用以改善米、大卖
30、和小麦的蛋白质质量。可惜的是，这种导致赖氨酸含量提高的基因工程也会导致蛋白质总量的降低和总产量的降低。以石灰水浸泡玉米似乎减少玉米中的一些营养素，但同时由于产生了较好的氨基酸平衡，从而改善了它的总营养价值。黑小麦这种黑麦和小麦的杂交种，它的赖氨酸和蛋白质的含量比小麦高，但每英亩产量较低。Structure of Cereals GrainsThe CellThe cell is the basic structural unit of cereals as of all foods of plant origin. A plant cell is bounded by a cell wall
31、which encloses the protoplasm or actual living part of the plant. The cell wall contains celluloses and hemicelluloses. The protoplasm consists of water (in large quantities in the living plant), protein, starch grains, fat globules and, in solution, water-soluble minerals, vitamins, and pigments.谷粒
32、的构造细胞 谷物像所有植物性食品一样，其基本结构单元式细胞。植物细胞的周缘是一层细胞壁，这层细胞壁将原生质即植物中真正具有生命力的组成部分包围起来，细胞壁含有纤维素和半纤维素。原生质由水（在活的植株中是大量的）、蛋白质、淀粉粒、脂肪球以及溶解的水溶液矿物质、维生素和色素。Parts of Cereal GrainNot all cells in a cereal grain are alike. Because of this, cereal grains can be separated in to three different parts: the bran, the germ or embryo, and the endosperm. The parts of a wheat kernel are illustrated as follows. The bulky bran consists of the outmost layer of cells of the grain. There cells have thick walls made mainly of cellulose and hemicelluloses. The main constituent in the bran of cereals is this indigestible
