Tài liệu giảng dạy tiếng anh chuyên ngành công nghệ thực phẩm

TRƯỜNG ĐẠI HỌC AN GIANG KHOA NÔNG NGHIỆP & TÀI NGUYÊN THIÊN NHIÊN BỘ MÔN CÔNG NGHỆ THỰC PHẨM  TÀI LIỆU GIẢNG DẠY TIẾNG ANH CHUYÊN NGÀNH CÔNG NGHỆ THỰC PHẨM Biên soạn: Lê Ngọc Hiệp Trần Phương Lan Hồ Thanh Bình 2016 English for Food Science and Technology Unit 1: FOOD SCIENCE AND FOOD TECHNOLOGY I READING COMPREHENSION Food Science Food science is a discipline concerned with all technical aspects of food, beginning with slaughtering, cooking and and harvesting ending or with consumption It its is considered one of the agricultural sciences, and is usually considered distinct from the field of nutrition Examples of the activities of food scientists include the development of new food products, design of processes to produce these foods, choice of packaging materials, shelf-life studies, sensory evaluation of the product with trained expert panels or potential consumers, as well as microbiological and chemical testing Food scientists at universities may study more fundamental phenomena that are directly linked to the production of particular food product and its properties In the U.S., food science is typically studied at land-grant universities Food science is a highly interdisciplinary applied science It incorporates concepts from many different fields including microbiology, chemical engineering, biochemistry, and many others Some of the sub-disciplines of food science include:  Food safety - the causes, prevention and communication dealing with foodborne illness  Food microbiology - the positive and negative interactions between microorganisms and foods Page | English for Food Science and Technology  Food preservation - the causes and prevention of quality degradation  Food engineering - the industrial processes used to manufacture food  Product development - the invention of new food products  Sensory analysis - the study of how food is perceived by the consumer's senses  Food chemistry - the molecular composition of food and the involvement of these molecules in chemical reactions  Food packaging - the study of how food is packaged to preserve the food after it has been processed  Molecular gastronomy - the scientific investigation of processes in cooking, social & artistic gastronomical phenomena  Food technology - the technological aspects  Food physics - the physical aspects of foods (such as viscosity, creaminess, texture ) The main organization in the United States regarding food science and food technology is the Institute of Food Technologists (IFT), headquartered in Chicago, Illinois, which is the US member organisation of the International Union of Food Science and Technology (IUFoST) The European national organisations are organised into the European Federation of Food Science and Technology (EFFoST), based at Wageningen University, the Netherlands (Source: http://www.umaine.edu/fsclub/) In the October 2006 issue of Food Technology, IFT President Dennis R Heldman noted that the IFT Committee on Higher Education gave the current definition of food science as follows: "Food Science is the discipline in which the engineering, biological, and physical sciences are used to study the nature of foods, the causes of deterioration, the principles underlying food processing, and the improvement of foods for the consuming public” The kind of careers that a food scientist might follow include food development, quality control, sensory specialist, flavor chemist, food safety, government, research, and education Page | English for Food Science and Technology Food Technology Food Technology, or Food Tech for short is the application of food science to the selection, preservation, processing, packaging, distribution, and use of safe, nutritious, and wholesome food Food science technology and food are interchangeably as used there is rarely any distinction between them While it is more likely that a food technologist would be working in industry rather than at research, all food scientists & technologists are concerned with the science required to understand and improve our food supply While both these definitions start to explain what food science it, there are still some misunderstandings Food scientists are not nutritionists I like to joke that food scientists’ interests in food stops once it reaches a consumer’s mouth, as that is our measure of success Actually, it should reach your mouth on more than one occasion You need to like the food product enough to want to eat it again, but is doesn’t necessarily need to be healthy or nutritious We care if it is safe; that is not contain harmful bacteria or toxins What the US food industry has achieved is quite amazing and it is due to food science that these advances have been made That does not mean we should stop trying to make the food supply even better Now the food industry has worked out how to make cheap long lasting food products, it should now try to fresh tasting long lasting food products But expect to pay more for them The cost of ingredients such as sugar, salt, and high fructose corn syrup, is much less than the cost of herbs and spices and other more flavorful ingredients Also the science and technology required to process food so that is Page | English for Food Science and Technology tastes freshly prepared despite having been kept in frozen storage for several months is complex and, therefore, more expensive (Source: http://cdavies.wordpress.com/2006/04/10/what-is-food-science/) II PRACTICES Questions 1) What is food science? 2) What are the activities of food scientists? 3) Let list some of the sub-disciplines of food science Which of them you like best? Why? 4) What can a food scientist do? 5) What is food technology? 6) According to the text, how is a safe food? 7) What is the target of food industry now? True-False: Write T if the sentence is true and F if it is false 1) _ Food science is considered one of the agricultural sciences, and is usually considered different from the field of nutrition 2) _ Food scientists at universities may study more fundamental phenomena that are not directly linked to the production of particular food product 3) _ Food microbiology - the positive of interactions between microorganisms and foods 4) _ The main organization in the United States regarding food science and food technology is the European Federation of Food Science and Technology (EFFoST) 5) _ Food science and food tech are used interchangeably as there is rarely any distinction between them Fill in these statements with the words in the box harvest package toxins food science bacteria preservation storage freezing fructose nutritionists 1) Foods vary in the temperature and moisture so they need to retain quality in Page | English for Food Science and Technology 2) Some species of fish can contain parasites, and will kill any parasites that may be present 3) is a study concerned with all technical aspects of foods, beginning with harvesting or slaughtering, and ending with its cooking and consumption, an ideology commonly referred to as "from field to fork" 4) Dietitians and plan food and nutrition programs, supervise meal preparation, and oversee the serving of meals 5) Clostridium are hard to clean away, because they produce endospores 6) , or fruit sugar, is a simple monosaccharide found in many plants 7) Reaping is the cutting of grain or pulse for , typically using a scythe, sickle, or reaper 8) Food are responsible for food poisoning which generally relates to agents produced by living organisms that have contaminated normally safe food 9) The food enclosed in the may require protection from, among other things, shock, vibration, compression, temperature, etc 10) Maintaining or creating nutritional value, texture and flavour is an important aspect of food III VOCABULARY - harvest (v): to gather, reap - slaughter (v): to kill or butcher (animals), esp for food - interdisciplinary (a): combining or involving two or more academic disciplines or fields of study - preserve (v): to keep safe from harm or injury/ to prepare (food or any perishable substance) so as to resist decomposition or fermentation - package (v): to group or combine (a series of related parts) into a single unit - molecular gastronomy: the application or study of scientific principles and practices in cooking and food preparation - degradation (n): the act of degrading - toxin (n): any poison produced by an organism Page | English for Food Science and Technology - freeze (v): to become hardened into ice - storage (n): the act of storing goods or the state of being stored Page | English for Food Science and Technology Unit 2: RICE I READING COMPREHENSION Rice is one of the world's most important food crops More than half of the people in the world eat this grain as the main part of their meals Nearly all the people who depend on rice for food live in Asia Rice is a cereal grain Like other cereal grain, including wheat, corn, oats, rice belongs to the grass family But unlike other grains rice grow in shallow water Rice thrives in many tropical areas because of their warm, wet climate Farmers usually flood rice fields to supply the growing plants with moisture and kill weeds and other pests The Rice Plant Young rice plants have a bright green color and as the grain ripens the plants turn goldenyellow The grain becomes fully ripe from 90 to 180 days after planting Structure: The parts of a mature rice plant are illustrated in Figure The rice plant consists of the roots, stems, leaves and panicle Each stem has at least five or six joints from which the long, narrow leaves grow The head also known as the panicle holds the kernels – that is the seeds or grains – of the rice plant Each panicle carries from 60 to 150 kernels Page | English for Food Science and Technology Figure Mature rice plant A typical rice kernel is 1/4 to 3/4 inches (6 to 10 millimeters) long The kernel has a hard covering called a hull that is not good to eat Underneath the hull are the bran layers, endosperm, and the embryo Several bran layers provide a touch coat for the kernel They contain many of the kernel’s nutrients The starchy endosperm makes up most of the kernel It is the part of the kernel from which a new plant grows Figure Whole-grain Rice Page | English for Food Science and Technology Uses of rice 2.1 Food Nearly all the rice produced in the world provides for people Rice supplies about half the calories in the daily diet of many people in Asia It is an excellent source of carbohydrates-nourishing substances that provide the body with energy Although low in protein, rice becomes an importance source of protein if eaten in large amounts Rice also has small amounts of the B vitamin-niacin, riboflavin and thiamine and the minerals – iron, phosphorus, potassium and sodium Rice has very little fat and easy to digest Most rice is eaten as milled white rice – rice that has had both its hull and bran layers removed Brown rice is more nutritious than white rice because the bran layers contain most of the kernel’s vitamins and minerals However, most people prefer white rice because it is less chewy than brown rice and takes about haft as long to cook White rice may be treated in various ways to make it more nutritious For example, much white rice is enriched with vitamins and minerals to replace the nutrients lost in removing the bran In areas where rice is the main food, enrichment helps prevent beriberi, a disease caused by lack of thiamine Rice may also be steamed under pressure with the hulls on before milling This process, called parboiling, makes the kernels less likely to break during milling In addition, parboiled rice keeps many of the vitamins and minerals usually lost during milling because these nutrients spread throughout the grain during parboiling Quick-cooking rice is partially cooked after milling The kernels become more absorbent in the process and need less time for final cooking 2.2 Other uses Rice appears in many processed foods, including certain breakfast cereals, soup, baby food, snack foods, frozen foods and flour Breweries use broken rice kernels to make mash, an important ingredient in beer In Japan, rice kernels are used to make an alcoholic drink called sake or rice wine Farmers may use rice hulls for fertilizer and add bran layers to livestock feed In industry, hulls are sometimes used as an ingredient in such products as insulation, cement and the liquid chemical furfural A few producers extract cooking oil from the bran Many people in Asia use the straw (dried stalks) from rice plants to thatch roots and weave sandals, hats, and baskets Page | English for Food Science and Technology - Extrusion is defined as forcing a pumpable product through a small opening to shape materials in a designed fashion Two kinds of extrusion machines popularly used are single screw extruders and twin-screw extruders II PRACTICES Questions What are the purposes of pasteurization and blanching? What is the purpose of commercial sterilization? What is the purpose of refrigerated storage? What are the basic methods for liquid concentration? What is the purpose of filtration? What are two main factors bringing about the distillation? III VOCABULARY - Retort (n) - Permeability (n) - Volatile (adj) - Crystal (n) - Dissolve (v) Page | 26 English for Food Science and Technology Unit 7: DRYING FOOD I READING COMPREHENSION Centuries ago, man discovered that removing moisture from food helps to preserve it, and that the easiest way to this is to expose the food to sun and wind Drying is one of the simplest methods of preservation, requiring little special equipment and expense It can be done out of door or indoor in an oven or specially built dehydrator Most foods can be successfully dried Since the quality is not improved and nutrients are not preserved by drying, it is important to begin with foods at the peak of their quality Some fresh fruits contain more than 90% water in the edible portion After the commercial drying, fruit contain up 25% water Fresh fruit juices and nectars contain 85 – 93% water The water content in these products is lowered in concentrated or sweetened juice products Cereals are characterized by low moisture contents Whole grains designed for long-term storage have 10-12% water Ripe raw nuts generally contain 3-5% water, or less The water of meat and fish depends primarily on the fat content and it varies with the age, source, and growth season of the animal or fish The water content of meat and fish ranges from 50-70%, but some organs may contain up to 80% water Water in poultry meats is between 50% (geese) and 75% (chicken) Fresh eggs have about 74% and dried eggs about 5% of water The water content of sausage varies widely Sun drying Many drying methods are satisfactory In warmer climates, sun drying may be a good method In climates where the daytime temperature reaches 100oF, the humidity is relatively low, and where the temperature remains hot at night sun drying can be very successful It may be necessary to move food inside at night to avoid condensation of dew on the partially dried foods Green vegetables are not usually satisfactory by drying in the sun because the ultraviolet light bleaches the chlorophyll so that the resulting products are a very pale green Oven drying Oven drying can be used, but it is difficult to maintain an oven at 140oF – 150oF If the temperature is higher than this, a dried crust can form on the outside of the food preventing the inner moisture from escaping Many flavoring compounds are very sensitive to heat and may be driven out of the food at higher oven temperatures The oven Page | 27 English for Food Science and Technology is expensive to use for drying An electric fan outside the oven will accelerate the drying process, but also uses more energy Drying in microwave ovens is not recommended by most drying authorities Microwave ovens are not adequately vented and therefore, moist air does not escape and this makes the drying difficult to adequately proceed Because of the rapid heating, microwave-dried products can also be cooked Another reason for not using the microwave oven for drying is that it is an expensive method Drying fruits and vegetables Most vegetables must be blanched prior to drying due to the enzymatic browning reactions The enzymes can be active even at moisture content too low for microorganisms to grow Vegetables not needing blanching are okra, onions, parsley, peppers, pimentos, mushrooms, horseradish as well as herbs Most fruits require some sort of pretreatments to prevent browning and loss of vitamin C Those, which need treatment, are grapes, persimmons and prunes The most effective pretreatment is sulfuring However, it is a rather complicated procedure and most people probably not accept Use of a bisulfite or ascorbic acid solution will reduce the browning and blanching will destroy the browning enzymes The drying process: drying time will be different because of differences in temperatures, airflow and food size Thus, it is necessary to judge the dryness subjectively Food must be cooled before being tested for dryness Different foods will have different criteria for dryness Foods that are dried in the sun may become contaminated from the air or insects It is a good idea to pasteurize these products before packaging Pasteurization may be accomplished by placing the foods in an oven at 175oF for 10 - 15 minutes This heats the surface without cooking the food Instead of heating, the microbial population can also be reduced (not eliminated) by freezing for two hours The food should be placed in an airtight container and allowed to sit for some times (two days or two weeks depending upon the food size) The food should be stirred once or twice per day If the food appears to become more moist, more drying is probably needed This process allows a redistribution of the moisture in case the food has dried unevenly After it has had a chance to become distributed evenly, more moisture will be removed Packaging: Food will keep top quality only if properly packaged The packaging materials must provide a barrier between the food and the air The food can pick up enough moisture from the air to support the growth of microorganisms The food will Page | 28 English for Food Science and Technology also maintain best quality if not exposed to light or metal An opaque material would shield out the light If a clear plastic wrap is used, the food should be stored in a dark place If dried food is stored in glass jars with metal lids, two layers of plastic wrap should be placed between the lid and the jar Keeping quality: most dried foods will maintain satisfactory quality for about one year The stronger flavored vegetables, such as onions and cabbage, can maintain top quality for only six months II PRACTICES A Questions Why should the food with good quality be choosen before drying? What foods that have less than 30% moisture? What are disadvantages of oven drying? Why is the microwave drying not so popular? Why vegetables and fruit require pretreatment before drying? Give example of some fruits and vegetables that need pretreatment before drying Why must the package of dried foods have gas and light barrier properties? III VOCABULARY - Dry (v) - Dehydrator (n) - Bleach (v) - Thermostat (n) - Perishable (adj) Page | 29 English for Food Science and Technology Unit 8: FERMENTATION TECHNOLOGY I READING COMPREHENSION Fermented foods are among the oldest processed foods and have formed a traditional part of diet in almost all countries for millennia Today they continue to form major sectors of the food processing industry, including baked products, alcoholic drinks, yoghurt, and cheese and soy products among many others During food fermentations, the controlled action of selected micro-organisms is used to alter the texture of foods, preserve foods by production of acids, or alcohol, or to produce flavours and aromas which increase the quality and value of raw materials Meat and fish products Pieces of meat are fermented by Bacillus spp and Staphylococcus spp and dried The fermentation cause flavour development and softening due to proteolysis, and preservation is by drying Fermented sausages are produced from a mixture of finely chopped meats, spice mixtures, curing salts, salt and sugar The meat is filled into sausage casings, fermented and pasteurized at 65-68oC for 4-8h, dried and stored at - 7oC Preservation is due to the antimicrobial action of nitrite-spice mixtures, lactic acid (0.84 - 1.2%) from the fermentation, heat during pasteurization and/or smoking, reduction in water activity due to salt and drying and low storage temperature In Southeast Asia, small fish, shrimp or waste fish are mixed with dry salt fermented by bacteria including L mesenteroides, P.cerevisiae and L plantarum to produce a range of sauces and pastes Proteins in fish are broken down by the combined action of bacterial enzymes, acidic conditions and autolytic action of natural fish enzymes Vegetables Cucumbers, olives and other vegetables are submerged in - 6% brine, which inhibits the growth of putrefactive spoilage bacteria Air is excluded and a naturally occurring sequence of lactic acid bacteria grows in the anaerobic conditions to produce approximately 1% lactic acid The importance of each species depends on the initial cell numbers on the vegetable, the salt content and the pH In some countries, the fermentation of cucumbers is controlled by addition acetic acid to prevent growth of spoilage micro-organisms Yoghurt In mechanized production, skimmed milk is mixed with dried skimmed milk and heated at 82-93oC for 30-60 minutes to destroy contaminating micro-organisms and to destabilize KPage | 30 English for Food Science and Technology casein It is inoculated with a mixture of Streptococcus thermophillus and Lactobacillus bulgaricus Initially S.thermophilus grows rapidly to produce diacetyl and lactic, acetic and formic acids L.bulgaricus possesses weak protease activity which release peptides from the milk proteins These stimulate the growth of S.thermophilus The increased activity then slows the growth of S.thermophilus and promotes L.bulgaricus L.bulgaricus produces most the lactic acid and also acetaldehyde which, together with diacetyl, gives the characteristic flavour and aroma in yoghurt Bread The fermentation and baking of cereal flours alter the texture and flavour of the flour and make it palatable as a staple food Fermentation has no preservative effect and the main function is to produce carbon dioxide to leaven the dough Yeast and other micro-organisms (e.g Lactobacillus spp.) present in the dough also contribute to the flavor of the bread Carbon dioxide is retained within the loaf when the gluten structure is set by heat above 74oC The heat treatment and reduction in water activity preserve the bread Soy products Soy sauce and similar products are made by a two-stage fermentation in which one or more fungal species are grown on a mixture of ground cereals and soy beans Fungal proteases, amylases and invertase act on the soy bean to produce a substrate for the second fermentation stage The fermenting mixture is transferred to brine and the temperature is slowly increased Acid production by Pseudorobillarda soyae lowers the pH to 5.0, and an alcoholic fermentation by Saccharomyces rouxii take place Finally the temperature is gradually returned to 150C and the characteristic flavour of soy sauce develops over a period of months to years The liquid fraction is separated, clarified, pasteurized and bottled The final product is preserved by 2.5% ethanol and 18% salt Vinegar and other food acids Ethanolic fermentation of wine, cider or malt by yeast is the first of two-part fermentation in the production of vinegar In the second stage the ethanol is oxidized by Acetobacter aceti to acetic acid and a number of flavour compounds This stage is sensitive to the concentration of dissolved oxygen, and fermenters are carefully designed to ensure that an adequate supply of air is maintained During maturing of vinegar, reactions between residual ethanol and acetic acid form ethyl acetate, which impart the characteristic flavour to the product Page | 31 English for Food Science and Technology Alcoholic beverages Beer wort is produced by boiling malted grains (for example barley) to release maltose and other sugar and, in some beers, by adding hop flowers to produce bitterness Developments in wort preparation include the use of hop extracts and dextrose syrups to increase product uniformity, and higher - temperature, shorter-time boiling to reduce energy consumption Variation in the composition of the wort, the strain of yeast, and the fermentation time and conditions result in the wide range of beers produced Cereals In tropical countries, cereals and root crops are fermented to a range of beverages and staple foods For example, fermented maize flour is staple food in many African countries Maize kernels are soaked for 1-3 days, milled and formed into dough Initially Corynebacterium spp hydrolyzes starch and initiate lactic acid production Aerobacter spp increase the rate of acid production and Saccharomyces cerevisiae contributes to the flavour of the product As the acidity increases, Lactobacillus spp predominates and continues acid production Finally Cadida mycoderma outgrows S cerevisiae and contributes to the final flavour of the fermented dough II PRACTICES A Question What is the usefulness of food fermentation? What are the bacteria usually used for meat fermentation? Where does the flavor of yoghurt come from? What are the effects of fermentation on bread baking? What are the two stages of fermentation in soy products? In African fermented maize flour, what are the roles of Corynebacterium spp., Aerobacter spp and Saccharomyces cerevisiae? III VOCABULARY - Proteolysis (n): the breaking down of proteins into the simpler compounds, as in digestion - Bake (v) to cook by dry heat in an oven or on heated metal or stones Page | 32 English for Food Science and Technology - detoxify (v) to remove the effects of poison from - submerge (v) to put or sink below surface of water or any enveloping medium - putrefactive (a) strong smelling - clarify (v) to make clear - dough (n) flour or meal combined with water, milk, etc., in a mass for baking into bread, cake, etc SYN: paste Page | 33 English for Food Science and Technology Unit 9: FREEZING FISH I READING COMPREHENSION Fish begins to spoil immediately after death This is reflected in gradual developments of undesirable flavors, softening of the flesh and eventually substantial losses of fluid containing protein and fat By lowering the temperature of the dead fish, spoilage can be retarded and, if the temperature is kept low enough, spoilage can be almost stopped Rigor mortis, which happens over a period of hours or days soon after death, can have significance on handling and processing The muscles under strain tend to contract, therefore, some of the tissue may break, especially if the fish is roughly handled, leaving the flesh broken and falling apart In some species the reaction can be strong, especially if the fish has to been chilled The freezing process alone is not a method of preservation It is a mean of preparing the fish for storage at a suitably low temperature In order to produce a good product, freezing must be accomplished quickly A freezer requires to be specially designed for this purpose and thus freezing is a separate process from low temperature storage Freezing fish Fish contains largely water, normally 60-80 percent depending on the species, and the freezing process converts most of this water into ice Freezing requires the removal of heat, and fish from which heat is removed falls in temperature in the manner shown in Figure1 Page | 34 English for Food Science and Technology Figure1: Temperature-time graph in fish during freezing During the fish stage of cooling, the temperature falls rapidly to just below the freezing point of water (0oC) As more heat requires to be extracted during the second stage, in order to turn the bulk of the water to ice, the temperature changes by a few degrees and this stage is known as the period of “thermal arrest” When about 55% of the water in turned to ice, the temperature again begins to fall rapidly and most of the remaining water freezes during this third stage A comparatively small amount of heat has to be removed during this third stage Once the water in fish freezes out as pure crystals of ice, the remaining unfrozen water contains an ever increasing concentration of salts and other compounds that are naturally present in fish flesh The effect of this ever increasing concentration is to depress the freezing point of the unfrozen water The result is that, unlike pure water, the complete change to ice of water in fish at this status is not accomplished at a fixed temperature of 0oC, but proceeds over a range of temperature The variation of the proportion of water which is converted to ice in the fish muscles against temperature is shown in Figure The figure shows that by the time the fish temperature is reduced to -5oC about 70% of the water is frozen It also shows that even at temperatures as low at -30oC, a proportion of water in the fish muscle still remains in the unfrozen state Figure 2: Freezing of fish muscle The percentage of water frozen at different temperatures Page | 35 English for Food Science and Technology Quick freezing Since the temperature just below 0oC is the critical zone for spoilage by protein denaturation, an early UK definition of quick freezing recommended that all fish should be reduced from a temperature of 0oC to-5oC in 2h or less The fish should then be further reduced in temperature so that its average temperature at the end of the freezing process is equivalent to the recommended storage temperature of -30oC With normal freezing practice in the UK, this latter requirement is defined by stating that the warmest part of the fish is reduced to -25oC at the completion of freezing When this temperature is reached, the coldest part of the fish will be at, or near, the refrigerant temperature of about – 35oC and the average temperature will then be near -35oC This is an elaborate definition of quick freezing and it is probably stricter than is necessary to ensure a good quality product The more widely used definitions of quick freezing not specify a freezing time or even a freezing rate but state that the fish should be frozen quickly and reduced in the freezer to intended storage temperature II PRACTICES A Questions What happens after fish die? What consequences does the rigor mortis cause for the fish after death? According to the text, what is the purpose of freezing fish? Describe three stages in freezing process of fish What is the percentage of liquid water in fish frozen at -30oC? What is quickly freezing definition applied in the UK? III VOCABULARY Retard (v): to delay, to postpone Bulk (v): to drawn together so as to wrinkle; to knit Denature (n): magnitude of material substance; mass; size Page | 36 English for Food Science and Technology Rigor mortis (v): to deprive of its natural qualities; change the nature of stiffening of the muscles of the body that occurs after death Page | 37 English for Food Science and Technology Unit 10: POSTHARVEST TECHNOLOGY OF RICE I READING COMPREHENSION The post-harvest technology consists of a set of operations which cover the period from harvest to consumption i.e harvesting, threshing, cleaning, drying, storage, milling and transportation to the market (or retention for farm family consumption) It is estimated that about 10 per cent of food grains produced in India are lost in processing and storage An efficient post-harvest system aims at minimizing losses and maintaining quality of the produce for final consumer In Haryana, rice harvesting is done manually as well as mechanically In regions, where sufficient work force is not available, harvesting with combine harvesters is in vogue These machines cut the crop, thresh it and deliver the clean grain in the grain tank The combine harvested rice generally has a moisture content of about 20 per cent and the grain must be dried immediately to about 12 per cent moisture content for storage The manually harvest crop is mainly threshed by manual beating, which is cleaned by using hand operated and power operated winnowing fans Usually the farmers clean paddy immediately after manual threshing First they use hand raking and shifting to remove straw chaff and other large and dense material followed by winnowing i.e making the grain fall down to be collected on a surface such as tarpaulin or a nylon sheet The sun drying of paddy is usually followed for domestic storage and further processing in rice mills When the rice grain is harvested, it is unusable as human food until the inedible hull is removed (hulling/dehusking) The whole kernels from which the hulls have been removed are known as brown rice Since the grain is usually consumed as white rice, the bran layer removed through a process called polishing or milling About half of the India’s rice- crop is parboiled Parboiling is a hydro-thermal treatment given particularly course and medium paddy to make the dehusking easy, to reduce breakage during milling The nutritive value of the grain also increases as parboiled rice reduces the losses of a vitamin B, riboflavin and niacin In Haryana, rice is milled by home-pounding or in mechanized rice mills In modern rice milling the cleaned paddy grains are first dehulled in a huller without damage to bran layer and rice kernel followed by separation of husked rice The husked rice is then polished to remove germ pericarp and aleurone layers Page | 38 English for Food Science and Technology The modern rice mills have better recovery and lower energy consumption compared to conventional hullers The husk is utilized for energy and industrial products like furfural 1and the bran for extraction of edible and non-edible grades oil Paddy on milling yields approximately 20% husk, 8% bran, 1% polishing and 70% rice The milled rice consists of unbroken kernel (the head rice) and broken kernels The mill recovery normally ranges from 65-70% depending on the rice variety To fetch better market price, grading of paddy is done mainly by thickness or length of grain using mechanical devices like rotating graders & colour grader/sorter Packaging is the next post-harvest operation which provides not only convenient handling in transportation and storage but also attracts consumers to pay more It is essential to avoid spoilage and to prolong the quality It is also important for long-term storage to fulfill the demand of old rice in the market, particularly in case of Basmati and non-parboiled rice In Haryana, most commonly used packaging materials are jute bags in addition to cloth bags, polythene impregnated jute bags and poly pouches For rice transportation, road and rail transport are normally used for internal markets while bullock cart or tractor’s trolley is used to transport the produce from field to storage or market Paddy, as well as rice is stored to maintain the supplies between two harvests Storage provides protection against weather, moisture, insects, micro-organisms, rats, birds and any type of infestation and contamination In Haryana, paddy/rice is stored in traditional as well as improved structures The traditional structures includes Mud bin, Thekka, Metal drums and Gunny bags whereas improved structures include different types of improved bins, brickbuild godowns, CAP (cover and plinth storage) and most advance silos The storage facilities are also available at mandi godowns, Central Warehousing Corporation, State Warehousing Corporations and Cooperative godowns The marketing of the produce is one of the most important operations The state has very well developed marketing system and various agencies like wholesale merchants and commission agents, village merchants, rice mill agents, co-operative organizations and government organisations (FCI, State Government, etc.) are engaged in its marketing II PRACTICES A Questions 1) How many stages operations cover the period from harvest to consumption? 2) What is brown rice? Page | 39 English for Food Science and Technology 3) What is parboiling? 4) What are the main provisions of rice for people? 5) According to the text, what are the main steps of rice processing? 6) Why is brown rice more nutritious than white rice? III VOCABULARY - Thresh (v): to remove the seeds of crop plants by hitting them, using either a machine or a hand tool - cereal (n): any plant of the grass family yielding an edible grain as wheat, rye, oats, rice or corn - moisture (n): condensed or diffused liquid, esp water - starch (n): a white, tasteless, solid carbohydrate, (C6H10O5)n, occurring in the form of minute granules in the seeds, tubers, and other parts of plants, and forming an important constituent of rice, corn, wheat, beans, potatoes, and many other vegetables foods - substance (n): that of which a thing consists; physical matter or material the act of degrading Page | 40