Instructors Guide for Food Science

8/3/2019 Instructors Guide for Food Science

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Section I: Introduction and BackgroundChapter 1:Overview of Food Science ............................................. 1 Chapter 2: Review of Chemistry ................................................. 3 Chapter 3: Chemistry of Foods ................................................... 5 Chapter 4: Nutrition and Digestion ............................................... 8 Chapter 5: Food Composition .................................................... 10 Chapter 6: Quality Factors in Foods .............................................. 12 Chapter 7: Unit Operations in Food Processing ..................................... 14 Chapter 8: Food Deterioration ................................................... 17

Section II: PresenrationChapter9:Heat ............................................................... 19 Chapter 10: Cold .............................................................. 21 Chapter 11:Drying and Dehydration .............................................. 23 Chapter 12: Radiant and Electrical Energy ......................................... 25 Chapter 13: Fermentation. Microorganisms. and Biotechnology ....................... 27 Chapter 14: Chemicals ......................................................... 29 Chapter15:Packaging .......................................................... 32

Section Ill: Foods and Food ProductsChapterl6:Milk .............................................................. 34 Chapter 17: Meat, Poultry, and Eggs .............................................. 37 Chapter 18: Fish and Shellfish ................................................... 40 Chapter 19: Cereal Grains. Legumes. and Oilseeds .................................. 42 Chapter 20: Fruits and Vegetables ................................................45 Chapter 21: Fats and Oils ....................................................... 48 Chapter 22: Candy and Confectionery ............................................ 51 Chapter 23: Beverages .......................................................... 54

Section IV: Related IssuesChapter 24: Environmental Concerns and Processing ............................... 57 Chapter 25: Food Safety ........................................................ 60 Chapter 26: Regulation and Labeling ............................................. 63 Chapter27:WorldFoodNeeds ................................................... 66 Chapter 28: Careers in Food Science .............................................. 69

Appendix A: Food Science Resources on the Internet .................................... 73 Appendix B: Suggested Resources .................................................... 76 Appendix C: Supply Companies ...................................................... 77


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To The TeacherLESSON PLANSThe textbook, Introduction to Food Science, is designed to be "teacher friendly." Each chapter beginswith a list of Objectives and Key Terms. Chapter outlines with different heading levels are very com-plete. Then every chapter ends with a list of Review Questions and Student Activities and a list ofResources.

A workable lesson plan includes the following:e The topice Overall instructional goale Rationale (why is this important)

Lesson outlinea Instructional procedurese Evaluation processe Materials and aidsLesson topics can come from the chapter titles or from a major heading in a chapter. Overall

instructional goals are listed for each chapter in this instructor's guide. The rationale for teachingthe lesson can come from a pretest or from some in-class demonstration or activity based on theStudent Activities section at the end of the chapter. The Lesson Outline comes directly from themajor headings in the chapter.

Instructional procedures need to be varied for different learning styles. In general, instruction-al procedures include:

Focusing event-something to get the students' attentione Teaching procedures-methods you will usee Formative check-progress check throughout the lessone Student participation-how you will get the students involved* Closure-how you will end the lessonAfter the lesson is presented, some type of evaluation process will measure outcomes to deter-

mine if the material has been learned. Finally, as lessons are prepared and plans made, a list ofmaterials needed and teaching aids should be developed. Each chapter provides a list of StudentActivities and Resources, including some ideas for using the Internet,

LESSON STRATEGIESPreview chapters with students. Start with the Objectives of the chapter, and then explain the impor-tance of knowing the meanings of the Key Terms. Explain that tables, figures, and figure captionscontain helpful information. Encourage the students to frequently use the Glossary in the back of thebook. All the Key Terms can be found in the Glossary.

Make reading assignments. Connect the reading assignments to the chapter Objectives and tothe use of the Student Activities section. Review the Resources at the end of the chapter for otherclass assignments or lesson enhancements.


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V i Ib the W h e rMake transparencies to use in the lesson discussion. Obtain any materials or make any

arrangements for some type of focusing event, student participation, or any of the Student Activitiesthat are used.

Decide which of the Review Questions at the end of the chapter to use as a pretest. This willhelp determine what the students know and stimulate interest. For example, use five of the questionsat the end of the chapter for a pretest.

To develop your lesson plan, start with the a pretest and an interest approach then build theclass discussion around the chapter outline, transparencies, problems, and student activities. Tables,lists, and figures or charts in a chapter can be used to produce transparencies.

Use the chapter sidebars. Make in-class reading assignments of the sidebars. Ask questionsabout the sidebar.

Summarize the chapter (lesson). Then assess how well the students met the objectives. Thiscan be done by giving the students a test or quiz based on the chapter objectives, or by developingprojects that reinforce the objectives. Also, at the end of each chapter in the textbook some sugges-tions are made as to how to search the Internet. Use these for some projects and reports.

Use the Appendix. It contains information to enhance learning. Table A-7 provides a list of spe-cific Internet sites leading to lots of valuable information that can be used to enhance the learningprocess. This table of Internet sites is reproduced at the back of this guide as Appendix A. Refer toAppendix TableA-8 in the textbook often. It is a fairly comprehensive food composition table that canenhance many of the lessons.

Besides Introduction to Food Science, other resource books are available that provide moredetails for some areas of food science, or they provide other ideas for teaching the subject. AppendixB in this guide suggests some resource books. Finally, a list of supply companies is provided inAppendixC at the back of this guide. These companies sell educational materials that enhance learn-ing through classroom activities and demonstrations. Also, many of the companies provide factsheets and newsletters that can be very helpful.

Above all, realize that students pick out the best teachers by their sincerity and their enthusi-asm for the subject and overall quest for knowledge. Let it show!


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Food ScienceOVERVIEWFood science strives to meet the demands of consumers in local, national, and international envi-ronments.SummaryConsumers vote every day in the marketplace with their dollars, and the market listens carefully totheir votes. A continuous feedback exists from consumers, who respond to the offerings of marketerstrying to meet the perceived wants of consumers. Changes in the makeup of the population, life-styles, incomes, and attitudes on food safety, health, and convenience have drastically altered theconditions facing producers and marketers of food products. Food manufacturers and distributorsmaintain vigorous efforts to meet changing consumer demands.The food industry is divided into production, manufacturing/processing,distribution, and mar-keting. The industry is highly responsive to change, and interrelated with others. Consumers drivethe food industry, and to some extent the food industry drives the consumer, making changes in foodconsumption, food types, and meals purchased. Food is now a global commodity due to changes inexport/import laws, transportation, and processing and communication.LEARNING OBJECTIVES&kr reading this chapter, the student should be able to:4B Name the four parts of the food industryO Describe consumer food buying trends$ Divide the food industry by major product lines@ Compare spending for food in the United States to that in other countries+B List four consumption trends8 Discuss trends in meal purchases69 Identify allied industries@ Explain how the food industry is internationalLesson Outline0bjectivesKey TermsParts of the Food IndustryTrendsAllied IndustriesInternational ActivitiesResponsiveness to ChangeInterrelated OperationsSummary


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2 Introduction to Food Science

Answers to ReviewQuestionsI. Away-from-home meals captures percent of the U.S. food dollar.

45 percent 2. Why have the international activities of food industries increased?

The international activities of food industries have increased because of improvements intransportation and communications.3. Name all seven product lines along which the food industry is divided.

cereals and bakery products; meats, fish, and poultry; dairy products; fmits and vegetables;sugars and other sweets; fats and oils; nonalcoholic/alcoholic beverages4. List the four artificial divisions of the food industry.

production, manufacture, distribution, marketing 5. Consumption of cheese has ,whereas consumption of red meat has over the

last 27 years. increased, decreased

6. List four reasons that influence people and the kind of food they eat.Any four of the following: demographic shifts; supply of ingredients; availability and costsof energy; politics; scientific advances in nutrition, health, and food safety; changes inlifestyle

7. About new food products are introduced each year. 10,000

8. Explain how the consumer votes in the marketplace. The consumer votes with how he/she spends money on what products.

9. Define an allied industry.An allied industry is directly associated with the food industry, such as cans for food, paperand plastic products such as paper plates and plasticware, chemicals such as preservatives,cooking equipment, or food regulatory agencies.

10. Compare the spending on food in the United States to that of Spain and Greece.The United States spends 7.9 percent, Spain spends 18.2percent, and Greece spends 31.7 p epcent of personal income on food consumed at home.


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3nstructor's Guide

Chapter 2Review oOVERVIEWThe study of food science requires an understanding of simple inorganic chemistry and organicchemistry principles.

Carbohydrates, lipids, and proteins, are all important to food science, and they are composed ofsmaller building blocks. This chapter contains a review of important chemical interactions and con-cepts encountered in food science.Atoms are the smallest unit of an element that still shows properties of the element. Atoms bondwith other atoms in chemical bonds such as covalent bonds, hydrogen bonds, ionic bonds, and Vander Waals bonds. Molecules are the smallest identifiableunits of pure substances. These moleculesare formed by chemical reactions or become involved in chemical reactions. Reactions includingthose of metabolism can be classified as oxidation-reduction. Organic chemistry involves carbon-containing molecules; such groups are hydroxyl, amino, ammonia, methyl, and carboxyl.LEARNING OBJECTIVES@r reading this chapter, the student should be able to:@ Describe the chemical properties of an element@ Name the three elements most important to life@ Explain how covalent, hydrogen, and ionic bonds are formedC9 Define a moleculeO Idenm symbols for hydroxyl, amino, ammonia, methyl, and carboxyl@ Discuss oxidation-reduction reactions@ Describe the two divisions of metabolism

Lesson OutlineObjectivesKey TermsElementsChemical BondsMoleculesReactionsMetabolismOrganic ChemistrySummary


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Answers to Review Questions1. The atom is the smallest unit of an that still exhibits the properties of that

element, element

2. Define a molecule.Molecules are the smallest identif'iable unit into which a pure substance can be divided andstill retain the composition and chemical properties of that substance.3. Name and describe the two divisions of metabolism.

Anabolism-reactions involving the synthesis of compounds; catabolism-reactions involv-ing the breakdown of compounds,4. List the elements most important to life.

Carbon, hydrogen, nitrogen, oxygen 5. How are covalent bonds formed?

Covalent bonds are formed by the sharing of a pair of electrons. 6. The atomic number of an atom is the total number of .The atomic weight of an atom is the total number of plus--

protons, protons, neutrons7. Salt is an example of a/an bond.

ionic 8. Explain the oxidation-reduction reaction.

Oxidation is the addition of oxygen, and reduction is the removal of oxygen. Oxidation-reduction reactions always involve a change in the oxidation state of the atoms or ions-aloss or gain of electrons.9. Chemical properties of an element are determined by the number of in the outermost energy level of an atom.

electron10. All carbon atoms have four bonds to account for. What are the names of the bonds?

another carbon, a hydroxyl, a hydrogen, an amino group, an oxygen (double bond)


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5nstructor's Guide

Chapter 3Chemistry oOVERVIEW -Nutrients are naturally occurring chemical substances found in food. There are six categories ofnutrients: proteins, lipids, carbohydrates, vitamins, minerals, and water. The chemistry of thesenutrients influences the characteristics of our food.

Nutrition is the process by which the foods people eat provide the nutrients they need to grow andstay healthy. The digestive and nutritive needs of humans are discussed in Chapter 4.Besides contributing to nutrition, carbohydrates, proteins, and lipids function in food. For exam-ple, carbohydrates enhance flavor, contribute to texture, prevent spoilage, and influence color. Thefunction of carbohydrates in foods to some extent depends on their type-monosaccharides, disac-charide~,or polysaccharides. Starch is a polysaccharide whose characteristics depend on the type ofplant producing the starch. Cellulose is a nondigestible polysaccharide that contributes to the char-acteristics of food, and demonstrates some health benefits. Proteins in food can act as emulsifiersand also influence the color, flavor, and texture of food. Lipids contribute to the texture, flavor, andheat transfer of foods. Lipids also carry the flavors and the fat-soluble vitamins. Food provides thevitamins and minerals necessary for normal growth and health. Although not a nutrient, water isnecessary for a solvent of all nutrients. Biotin, choline, and phytochemicals are nutrients that seemto have some health benefits but do not have clearly defined requirements.

LEARNINGOBJECTIVES/Ifter reading this chapter, the student should be able to:@ Name four carbohydrates and describe their chemical makeupti9 Classify carbohydratesO Compare the sweetness of various sugars4B Name three uses of carbohydrates in foodsO Describe the chemical makeup of proteins@ Discuss the use of proteins in foods43 List six functions of protein in the body@ Name three functions of protein in food@ Classify lipids@ Discuss the use of lipids or fats in foods@ Identify saturated and unsaturated fatsf3 List the fat- and water-soluble vitamins@ Name ten minerals important in nutritionQ List two functions of water in the bodyQ Identify biotin, choline, and phytochemicals


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6 Introduction to Food ScienceLesson OutlineObjectivesKey TermsCarbohydratesProteinsLipidsVitaminsMineralsWaterBiotinCholinePhytochemicalsSummary

Answers to Review Questions1. What is the chemical composition of a carbohydrate?carbon, hydrogen, oxygen

2. List the three functions of proteins in food.color, flavor, texture

3. What is the difference between a monosaccharide and a disaccharide?Monosaccharides may have six carbons and are called hexoses, or they may have fivecapbons and are called pentoses. Two monosaccharides may be linked together to form a dis-accharide.

4. Name five functions carbohydrates play in foods.Any five of the following: flavor enhancer and sweetener flavor due to caramelization;water binder; contribute to texture (starch, gluten); hygroscopic nature/water absorption;provide source of yeast food; regulate gelation of pectin dispersing molecules of protein orstarch; act to subdivide shortening for creaming control crystallization; prevent spoilage;delay coagulation protein; give structure due to crystals; affect osmosis; affect color ofh i t s ; Meet texture (viscosity, struchue); contribute flavor other than sweetness

5. Explain two functions of water in the body.Any two of the following: carries nutrients and wastes; maintains structure of molecules;participates in chemical reactions; acts as a solvent for nutrients; lubricates and cushionsjoints, spinal cord, and fetus (during gestation); helps regulate body temperature; main-tains blood volume

6. Triglycerides, fatty acids, phospholipids, some pigments, some vitamins, and cholesterol a re classed as lipids


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7nstructor'sGuide

7 Fatty acid molecules that are contain what are known as double bonds. A fatty acid that contains one double bond is called mono .Fatty acids that contain two or more double bonds are called . unsaturated, unsaturated, polyunsaturated

8. List the fat- and water-soluble vitamins.Fat-soluble vitamins: A, D, E, K; water-soluble vitamins: thiamin, riboflavin, niacin, vita-min C, vitamin Biz9. is part of several major phospholipids critical for normal membrane structure and function, is used by the kidney to maintain water balance, and is used to produce the important neurotransmitter acetylcholine.

Choline10. Name ten minerals important in nutrition.

Macrominerals: calcium, phosphorus, potassium, sodium, chloride, magnesium, sulfur;microrninerals: chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybde-num, nickel, selenium, silicon, tin, vanadium, zinc


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rition and Diges Nutrients-the components of food-have specific functions in the body, and all of them together arerequired for overall health. The digestive system breaks down food into nutrients for absorption.

SummaryPeople require energy and certain other essential nutrients. These nutrients are essential becausethe body cannot make them and must obtain them from food. Essential nutrients include vitamins,minerals, certain amino acids, and certain fatty acids. Foods also contain other components such asfiber that are important for health.The Food Nutrition Board of the National Research Council establishes Recommended DietaryAllowances and Dietary References Intakes. These guidelines provide daily nutrient levels for main-taining normal functions and health. The RDA lists recommendations for energy; protein; vitaminsA, E, K, C, the B vitamins; and the minerals iron, zinc, iodine, and selenium. These recommenda-tions vary according to age, gender, pregnancy, and lactation. Protein requirements for humansshould consider the essential amino acids. The food pyramid provided by the FDA is easy for theaverage person to follow to ensure adequate nutrition.The digestive process includes ingestion, digestion, absorption, and elimination. Nutrients in thediet are progressively broken into smaller components by mechanical, chemical, and enzymaticmeans. Small molecules resulting from digestion are absorbed to supply the body with energy, pro-tein, vitamins, and minerals.LEARNING OBJECTIVES&r reading this chapter, the student should be able to:d Identify nutritional needs using RDA or DRI48 Discuss the functions of energy, carbohydrates, fats, and proteins in the bodyO Provide the caloric content of proteins, carbohydrates, fats, and alcohol@ List the essential amino acids8 Name two protein-deficiency diseases8 Describe protein quality

Name an essential fatty acid@ List the water- and fat-soluble vitamins and their functions63 List six minerals required by the body@ Describe the process of digestion9 Identify the organs involved in digestion69 Discuss the relationship of diet to health

Lesson OutlineObjectivesKey Terms


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Instructor's Guid e

Nutrient NeedsWaterFood PyramidDigestive ProcessesVegetarian DietsBioavailabiltiy of NutrientsStability of NutrientsDiet and Chronic Diseasesummary

Answers to ReviewQuestions1. Name six minerals required by the body.

Any six of the following: calcium, phosphorus, iron, copper, magnesium, sodium, potassi-um, chloride, zinc,iodine, manganese, selenium

2. Identify the protein requirement for a 19-year-old male and female. Male-58 grams; female-46 grams

3. Describe the function of protein in the diet. To provide amino acids, energy, and nitrogen

4. How many calories are in 1gram of protein, carbohydrate, fat, and alcohol?4 calories per gram for proteins and carbohydrates; 9 calories per gram for fat; 7 caloriesper gram for alcohol

5.-acid is an essential fatty acid. Linoleic 6. Identify the organ of digestion that receives enzymes from the pancreas. duodenum 7. During digestion, enzymes such as aminopeptidases, carboxypeptidases, and dipeptidases con-vert polypeptides into .

amino acids8. What nutritional deficiency causes kwashiorkor and marasmus?

protein; protein and calories 9. List five essential amino acids.

Any five of the following: phenylalanine, tryptophan, histidine, valine, leucine, isoleucine,lysine, methionine, threonine10. What factor determines protein quality?

amino acid content


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Chapter 5Food Compos

. .... .................................... - --- - - .--------- --.---- - ---.Food composition tables are used to evaluate diets and food supplies.

SummaryFood composition tables are used to evaluate the nutritional value of food supplies, to develop fooddistribution programs, to plan and evaluate food consumption surveys, to provide nutritional coun-seling, and to estimate the nutritional content of individual diets.Methods such as spectrophotometry, iquid chromatography, and gas chromatography determinethe composition of foods. The bomb calorimeter measures the caloric content of foods. Many foodcomposition tables are available, but the USDA maintains and updates data on the composition offoods.

LEARNING OBJECTIVES &r reading this chapter, the student should be able to: @ Find foods in a food composition table and describe their nutritional value@ List three methods of determining the composition of foods@ Describe the method for determining the caloric content of foods@ Explain the difference between Calorie and calorie@ Identify common abbreviations and terms used in a food composition table69 Discuss the use of food composition tables$ List four factors that affect the nutrient content of foods

Lesson Outline0bjectivesKey TermsDetermining the Composition of FoodsEnergy in FoodFood Composition TablesSummary

Answers to Review QuestionsNote: The answers to some of these questions will be found by using Table A-8.1. How many Calories and grams of protein are in 3 oz. of Froot Loops' cereal?

Protein-6 grams; Calories-530


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Instructor's Guide

2. How many grams of fat are in one slice of cheese pizza?9 grams of fat

3. Describe item #4270.Chocolate chip cookie, home recipe

4. List three methods for determining the composition of foods.Any three of the following: proximate analysis, bomb calorimeter, spectrophotomehy, liq-uid chromatography, gas chromatography

5. A is defined as the amount of heat required to raise the temperature of one gram one 'C?calorie

6. Describe two uses of a food composition table.Any two of the following: evaluate the nutritional value of food supplies, develop food dis-tribution programs, plan and evaluate food consumption surveys, provide nutritionalcounseling, estimate the nutritional content of individual diets

7. Name four factors that affect the nutrient content of foods.Any four of the following: variety, season, geographical differences, stage of harvesting,handling, commercial processing, packaging, storage, display, home preparation, cooking,and serving

8. Explain the relationship between Calorie, Kcal, calorie, and cal.A Calorie is a metric unit of heat measurement. The small calorie (cal) is the amount ofheat required to raise the temperature of one gram of water one degree.A large Calorie, orkilocalorie (kcal), usually referred to as a calorie and sometimes as a kilogram calorie,equals 1,000 cal. This unit is used to express the amount of energy that a food provideswhen consumed,

9. Identify the following abbreviations: oz., mg, IU, RE, mono, sat, poly, carb, chols.oz.: ounce; mg: milligram; IU: International Units; RE: retinol equivalents; mono: mono-saturated; sat: saturated; poly: polyunsaturated; carb: carbohydrate; chols: cholesterol

10. In terms of energy and protein, what is the difference between a slice of white bread and aslice of whole wheat bread?Whole wheat bread contains 15more calories per slice and one more gram of protein thanwhite bread.


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Chapter 6Quality Factors in FoodsOVERVIEWConsumers expect certain qualities fkom their food, including color, flavor, texture, and even size.Food science works to maintain these qualities.SummaryQuality of a food product involves maintenance or improvement of the key attributes of the product-including color, flavor, texture, safety, healthfulness, shelf life, and convenience. To maintain quality,it is important to control microbiological spoilage, enzymatic degradation, and chemical degrada-tion. These components of quality depend upon the composition of the food, processing methods,packaging, and storage.When quality factors are missing or different than expected, the food is rejected. Food sciencedetermines and uses methods to measure food-quality factors. These methods ensure a consistent,reliable product. Some evaluation methods are chemical and mechanical techniques. Others are com-pletely human, such as taste panels. The USDA-AMS establishes quality and grading standards. Also,in cooperation with industry, the AMS develops and maintains c o m m ~ a ltem descriptions for hun-dreds of items. Within the food industry, methods such as HACCP, TQM, and GMP monitor quality.

LEARNINGOBJECIlYESm r eading this chapter, the student should be able to:@ Describe the influence of color on food quality8 Identify the instrument that could be used to measure food texture@ Discuss the influence of color, texture, size, and shape on consumer acceptance@ Describe how water changes textureO Identify six words used to describe food flavor@ Describe sensory methods humans use to determine food flavorO Discuss three factors that can affect food flavor43 Explain three means for maintaining or assessing quality in foods@ Describe the role the USDA plays in food qualityLesson OutlineObjectivesKey TermsAppearance FactorsTextural FactorsFlavor FactorsAdditional Quality FactorsQuality StandardsQuality Controls-w


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Instructor's Guide

Answers to Review Questionst ist the three components of reflected light used to derine colors.

value, hue, chroma 2. Name one instrument used to measure texture.

Any one of the following: tendemmeter, succulometer, Brookf'ield viscometer, Instron,Warner Bratzler, penetrometer3. Discuss what humans can taste and what they smell and how this forms food flavor.

Humans can taste sweet, salty, sour, bitter; they can smell aromas; taste and smell are usedinterchangeably.4. Identify the following acronyms: AMS, HACCP,TQM,GMP, CID.

Agricultural Marketing Service, Hazard Analysis and Critical Control Point, Total QualityManagement, Good Manufacturing Practices, Commercial Item Description5. Industry and develop and maintain CIDs.

AMS (Agricultural Marketing Service) 6. List six factors that can influence the flavor of food.

Any six of the following: color, texture, bacteria, yeasts, molds, enzymes, heatlcold, mois-ture/dryness, light, time, additives, shelf life, healthfulness, convenience7. Changes in the texture of food are often due to .

water 8. What qualities do consumers expect of their food?

good color and good size and shape 9. The study of the science of the deformation of matter is called .

rheology 10. How do fats or lipids affect the texture of food?

Lipids are softeners.


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t Operations inFood ProcessingOVERVIEWMost food processing is comprised as a series of physical processes that can be broken down into anumber of basic operations.

SummaryUnit operations make up the basics of food processing. These unit operations can stand alone anddepend upon logical physical principles. Unit operations include materials handling, cleaning, sep-arating, size reduction, fluid flow, mixing, heat transfer, concentration, drying, forming, packaging,and controlling.Most food processing involves a combination or an overlap of these unit operations. Where unitoperations overlap or are combined, complex controls ensure the proper function of each operation.Many of the unit processes discussed in this chapter are discussed in more detail in chapters thatfollow.LEARNING OBJECTIVES&r reading this chapter, the student should be able to:@ Describe materials handling in the food industry@ Name three methods of reducing the size of a food product@ Name three methods for separating food products@ Identify two general types of pumps@ Describe four factors that affect mixing@ Describe five factors influencing heat transfer43 Identify five unit processes that include heat transfer@ Discuss the uses of three common methods of drying@ List two examples of a formed food@ Describe the purposes of concentrationO Identify two reasons for packaging food productsO Discuss why some unit operations overlap

Lesson OutlineObjectivesKey TermsMaterials HandlingCleaningSeparating


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Instructor's Guide

Size ReductionPumping (Fluid Flow)MixingHeat ExchangingConcentrationDryingFormingPackagingControllingOverlapping OperationsConserving EnergyNew ProcessesSummary

Answers to Review Questions1. The manufacture of ice cream is an example of a/an

overlapping operation2. Why are foods packaged?

Foods are packaged for shipping; dispensing; improving the usehlness of the product; pro-tection fkom microbial contamination, dirt, insects, light, moisture, drying, flavor changes,and physical alterations; and for marketing and selling purposes.3, is the amount of heat required to change the temperature of a unit mass of prod-uct a specific temperature without changing the material.

Specific heat4. Name the three methods for separating foods.

cream separator, clM ~c at ion, embrane processes5. What are the two types of fluid flow pumps?

Centrifugal and positive6.-heat exchanges pass fluid over a plate where a heating or cooling medium is being passed up or down on the other side of the plate.

Plate7. List the four factors affecting the mixing of food products.

Design of impeller, diameter of impeller, speed, baffles8. Why is it important to handle food materials carefully?

Food materials should be handled correctly for sanitary reasons, to minimize losses, tomaintain the quality of the food, and to minimize bacterial growth.


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9. Explain the three common methods of drying foods.The three common methods of drying food are (1) sun or tray drying, which is exposingthe product to sun or placing it in trays and drying in a current of warm or hot air; (2) spraydrying-spray nozzles are used to atomize the fluid into the heated air; and (3) f'reeze dry-ing-the moisture is removed without a phase change (sublimation).

10. List three membrane processes for separating food products.reverse osmosis, ultraf"~ltration,microfiltration


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17nstructor's Guide

Chapter 8Food DeOYERVIEWFood science seeks to minimize food deterioration as much as possible.

SummaryDeterioration includes changes in organoleptic quality, nutritional value, food safety, aestheticappeal, color, texture and flavor. To some degree, all foods undergo deterioration after harvest Therole of food science is to minimize negative changes as much as possible.

All foods undergo deterioration-physical, chemical, or biological. There are many ways to con-trol this deterioration-from proper handling in the initial stages of harvesting to correct food preser-vation techniques. Some deterioration produces toxins that are not destroyed by heat. Some of thesetoxins can cause infections in humans. All foods from living tissues have enzymes. Some of the post-harvest enzymes are desirable and are controlled by heat, chemicals, and radiation. Food processorsrealize the importance of controlling deterioration through such means as heat, cold, drying, acids,sugar, atmosphere, chemicals, and radiation.

LEARNING OBJECTIVES@r reading this chapter, the student should be able to:@ List three general categories of food deterioration@ Discuss shelf life and dating6B Name six factors that cause food deterioration@ Identify six preservation techniques that prevent deterioration@ Describe normal changes in food products following harvest or slaughter@ Identify four food enzymes and describe their function

Lesson OutlineObjectivesKey TermsTypes of Food DeteriorationShelf Life and Dating of FoodsCauses of Food DeteriorationPost-Harves t Biochemical ChangesPost-Slaughter Biochemical ChangesPrinciples of Food PreservationSummary


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Answers to Review Questions1. Name the two environmental conditions that affect microbial growth on food.

temperature and oxygen 2. Name the three general categories of food deterioration.

physical, chemical, biological 3. Some are desirable in food preservation.

microorganisms 4. Why do foods have a shelf life?

Foods are given a shelf life to determine usefulness. 5. The growth of aerobes is slowed by removing the ;while providing limits the

growth of anaerobes. oxygen, oxygen

6. List four factors that cause food deterioration.Any four of the following: microorganisms; activity of food enzymes; infestations by insects,parasites, and rodents; inappropriate temperatures during processing and storage; gain orloss of moisture; reaction with oxygen; light; physical stress or abuse; time

7. What is a food-borne disease? A food-borne disease is an infection in a human when infected food is consumed.

8. Give four preservation techniques to prevent food deterioration.Any four of the following: heat, cold, drying, acid, sugar, salt, smoke, atmosphere, chemi-cals, radiation

9. Why are some fruits and vegetables washed immediately after being picked? Fruits and vegetables are washed af'ter being picked to begin removing internal heat

10. Name four food enzymes and describe their fbnction.Use enzymes from Table 8-2 (text pages 129-131).


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19nstructor's Guide

Chapter 9 Heating (cooking) foods kills some microorganisms, destroys most enzymes, and improves shelf life.

Heat produces varying degrees of preservation depending on the product and the use of the product.Heat treatments can be selected on the basis of time and temperature combination to inactivate themost resistant microbe and the heat penetration characteristics of the food and the container. Themost heat resistant microbe in canned foods is Clostridium botulinum Thermal death curvesdescribe the time/temperature relationships for preservation of food.Depending on the type of food and its acidity, the heat treatment can be mild or severe.Convection, conduction, and radiation transfer heat to the processed foods. Commercially, foods areheated before or after packaging. Different types of retorts efficiently process commercial foods.Aseptic packaging is used when the food is sterilized outside the container. Home canning followsthe same principles as commercial heat preservation methods.

LEARNINGOBJECTIVESlqpter reading this chapter, the student should be able to:@ Name four degrees of preservation achieved by heating@ Describe how specific heat treatments are selected@ Identify how the heat resistance of microorganisms is determined@ Discuss methods of heating foods before or after packaging@ Describe one type of retort@ Compare conduction and convection heating@ Explain time-temperature combinations@ List three factors that influence how foods heat43 Describe a thermal death curve8 Compare the acidity of various foods to the heat treatment required

Lesson outl3neObjectivesKey TermsHeatDegrees of PreservationSelecting Heat TreatmentsHeat Resistance of MicroorganismsHeat TransferProtective Effects of Food Constituents


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Different Temperature-Time CombinationsHeating Before or After PackagingHome Canningsummary

Answers to Review QuestionsI.The most heat resistant microbe in canned foods is

Clostridium botulinum

2. What are the two main objectives of pasteurization?(1) Destroy all pathogenic microorganisms that might grow in a specfic product; and (2)extension of shelf life by decreasing number of spoilage organisms present

3. Name four types of preservatives achieved by heating. sterilization, commercial sterility, pasteurization, blanching

4. In the thermal death curve, the D value relates to the to reduce the number ofmicroorganisms, and the Z value relates to the required to decrease the microorgan-isms.time, temperature

5. Heating after packaging requires what type of packaging? aseptic

6. heating is thermal transfer due to collisions of hot food particles with cooler ones.Conduction7. What is the difference between a still retort and an agitating retort?A still retort is when the product is placed in a container and then heated in a steam atmos-phere without agitation. An agitation retort agitates the product during cooking and allowsfor the use of high temperatures during processing.

8. Identify the two factors to pick the right heat treatment severity for a specific food.(1) Time-temperature combination required to inactivate the most resistant microbe; (2)heat penetration characteristics of the food and the container

9. Define conduction heating. Conduction heating is the transfer of heat fkom one particle to another by contact.

10. is the transfer of energy in the form of electromagnetic waves. Radiation


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Instructor's Guide 21

Chapter 10 OVERVIEWCold (cool) storage, refrigeration, and frozen storage are methods of food preservation and process-ing differing in temperature and time.

Various methods of using cold take food to temperatures necessary for cold storage or frozen stor-age. Freezing and refrigeration preserve foods not because they destroy microbes but because theyslow or stop microbial growth. Refrigeration temperatures range from 40" to 45F; frozen storagetemperatures range from 32" to OF.Refrigerated storage also requires air circulation, humidity con-trol, and a modii3ed gas atmosphere. During refrigerated storage, foods can experience the absorp-tion of flavor, a loss of firmness, color, flavor, and sugar.Freezing technology has been key to the development of convenience foods. Foods properlyfrozen and stored experience minimal changes in food quality. Frozen storage varies with tempera-ture and the type of food being stored. General freezing methods include still air, blast freezer, andfluidized-bed freezer. Single plate, double plate, and slush freezers freeze foods or packages thatdirectly contact a cold surface. Immersion freezing is the direct contact of the food or package andthe refrigerant such as liquid nitrogen. To maintain quality, frozen foods must be packaged in airtightand liquid-tight strong and flexible containers.Home freezing of foods follows the same general principles as commercial freezing.LEARNINGOBJECTIVES@r reading this chapter, the student should be able to:@ Compare cooling, refrigeration, and freezing@ Identify four requirements for refrigerationO Correlate storage temperature to length of storageO Compare requirements for refrigeration to those of freezing43 List three methods of freezing@ Describe changes in food quality that may occur during refrigeration or freezingO Compare home freezing to commercial freezing

Lesson OutlineObjectivesKey TermsRefrigeration versus FreezingRefrigeration and Cool StorageFreezing and Frozen StorageNew DevelopmentsHome FreezingSummary


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Answers to Review Questions1. Name the three methods of freezing.

Freezing in air such as blast fieezer; fieezing where food packages directly contact a supface that is cooled by a rewgerant; immersion fkeezing2. List the four requirements of refrigerated storage.

low temperatures,air circulation, humidity control, modified gas atmosphere 3. Identify four changes in food during refrigeration.

Any four of the following: chill injury; flavor (odor) absorption; loss of firmness, color, fla-vor, and sugar4. A key factor in food fkeezing is how the food is frozen.

fast 5. Describe the temperature difference between cooling, refrigeration, and freezing.

Cooling-temperatures from 68"to 28OF;refkigeration-temperatures fkom40"to 45OF;f'reez-ing-temperatures fkom 32' to OF6. Why do food processors blanch vegetables prior to freezing them?

Blanching is a mild heat treatment designed to inactivate enzymes. 7. Name the two types of containers for home freezing use.

Rigid containers and flexible bags or wrappings 8. Freezing cannot improve the or texture of any food.

flavor 9. Explain why a freezer should not be overloaded with u@ozen food.

Overloading the fieezer slows down the freezing rate, and foods that fieeze too slowly maylose quality.10. List the three things packaging for frozen foods protects against.

dehydration, light, air


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Instructor's Guide 23

Chapter 11Drying and DehydraOVERVIEW............................................. .. ..Besides preservation, drying and dehydration decrease the weight and volume of a product andthereby decrease shipping costs.SummaryDrying and dehydration both remove water from foods. Dehydration occurs under natural conditionsin the field and during cooking. Dehydrated and dried foods are lighter, take up less space, and costless to ship.Drying is affected by surface area, temperature, humidity, and atmospheric pressure. As foodsdry, they demonstrate a typical drying curve. Some chemical changes that can occur during dehy-dration include caramelization, browning, loss of rehydration, and loss of flavor. Foods can be driedby air convection, drum,vacuum, or freeze-drying.Food concentration removes one third to two thirds of the water and reduces weight and volume.Methods of concentration include solar, open-kettle, flash evaporators, thin-film evaporators, freezeconcentration, and ultrafiltration or reverse osmosis.Home drying of foods follows the same general principles a s commercial processes. Smallhome dehydrators are available or can be built. The kitchen oven (or microwave) can also be usedfor drying foods.

LEARNING OBJECTIVES &zr reading this chapter, the student should be able to: @ Discuss two reasons for dehydrating foods9 Describe changes that occur during dehydratingQ List three factors affecting dehydration@ Identify chemical changes that can occur in food during drying@ List two problems that can occur during drying@ Identify reasons for food concentration69 Describe three drying methods@ Describe the methods of food concentrationO Compare home drying of foods to commercial drying

Lesson OutlineObjectivesKey TermsDehydrationFood ConcentrationHome DryingS-ary


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Answers to Review Questions1. List the three drying methods.

Any three of the following: air convection, drum, vacuum, freeze 2. Dehydration results in decreased and and shipping costs.

weight, volume 3. Vacuum drying produces the highest quality of product but is also very .

expensive 4. What is ultrafiltration?

Ultrafiltration is a membrane filtration process operating at 2 to 10 bars (international unitof pressure equal to 29.531 in. of mercury at 32'5') pressure and allowing molecules the sizeof salts and sugars to pass through the membrane pores, while molecules of the size of pro-teins are rejected.5. The principle of is that under conditions of low vapor pressure (vacuum), water evaporates &om ice without the ice melting.

6. The purpose of drying is to remove enough moisture to prevent growth. microbial

7. Define sublimation.Sublimation is when water goes from a solid to a gas without passing through the liquidphase.

8. What types of foods are dried using drum or roller driers? liquid foods, purees, pastes, and mashes

9. Discuss the two problems with drying of a food product.The two problems with drying products are (1) the rate may be too low and organisms maycause spoilage before the product can be dried; and (2) problems with contamination ofthe product.

10. List three chemical changes that occur during drying.Any three of the following: caramelization, enzymatic browning, nonenzyrnatic browning,loss of ease of rehydration, loss of flavor


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25nstructor's Guide

Chapter 12Radiant and EEnergyIonizing radiation, microwaves, and ohmic heat are new methods for heating and preserving foods.

summaryIonizing radiation and microwaves are invisible energy waves moving through space. Food proces-sors use these two forms of radiation. Electrical or ohmic heating of foods is a relatively new methodfor heating and preserving foods.Ionizing radiation (irradiation) and microwaves are both used to preserve food. Although irradi-ation has been in use since 1950, the FDA must approve its uses on each additional food. The latestapproval for irradiation occurred in 1997 for fresh and frozen red meats. Irradiation serves four usesin the food industry: preservation; sterilization; control of sprouting, ripening, and insect damage;and control of foodborne illness. Though irradiation demonstrates little effect on nutrient content,the greatest challenge will be consumer acceptance. Microwaves are also used to heat foods by gen-erating heat inside the food due to water friction. Scientists refer to microwaves as nonionizing radi-ation.Microwave development has led to a whole new group of convenience foods. Attempts to usemicrowave energy in food processing include baking, concentrating, cooking, curing, drying, heat-ing, puffiing, foaming, tempering, and thawing. The best use of microwaves depends on the productquality and the cost.Ohmic heating heats foods between electrodes using alternating current. It is one of the newestmethods of heating, and it is useful because solid and liquid in a food are heated at the same time.LEARNING OBJECTIVES &er reading this chapter, the student should be able to: @ Describe ionizing radiation@ Name two requirements for the irradiation process@ Discuss the four areas in which irradiation is most usefulO List the three specific ways the FDA has approved irradiation uses43 Explain how microwaves heat food

Describe ohmic (electrical) heating and its major advantage8 Explain why salt and water content are important in microwave heating

Lesson OutlineObjectivesKey TermsFood IrradiationMicrowave Heating


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26 Introduction to Food ScienceOhmic (Electrical) Heatingsummary

Answers to Review Questions1. Describe ohmic heating.Ohmic heating is the heating of a food product by using an alternating current flowingbetween two electrodes.2. Name the two requirements for irradiation.

The two requirements for the irradiation process are (1) a source of radiant energy, and (2)a way to confine that energy.3. Radiation is broadly defined as moving through space in invisible waves.

energy 4. Explain ionizing radiation.

Radiant energy has different wavelengths and degrees of power. Ionizing radiation is shortwavelengths capable of damaging microorganisms that contaminate food or cause foodspoilage and deterioration.5. List the four ways in which irradiation is most useful.

(1)preservation; (2) sterilization; (3) control of sprouting and ripening, and insect damage;and (4) control of foodborne illness6. Describe how microwaves heat food.

Microwaves generate heat inside a food due to water fiction. 7. When is added to water, it changes the microwave heating characteristics in two differ-ent directions.

salt8. List three specific ways irradiation has been approved for use by the FDA.

Any three of the following: eliminating insects from wheat, potatoes, flour, spices, tea,fruits, and vegetables; to control sprouting and ripening; to use on pork to control trichi-nosis; to control Salmonella and other harmfulbacteria in chicken, turkey, and other freshand frozen uncooked poultry; to control pathogens in fkesh and fkozen red meats9. Food composition influences microwave heating of food in what two ways?

(I) water loss factor; (2) penetration depth of microwaves10. Irradiation cannot be used on what two specific products?

(I) milk; (2) some fruits such as peaches and nectarines


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27nstructor's Guide

Chapter 13Fermentation, Microorganisms,and BiotechnoOVERVIEWFood science develops the use of fermentation, microorganisms, and biotechnology to alter, improve,and preserve food.

Fermentation allows the growth of microorganisms in order to produce a stable product Productscommonly produced, at least in part, by fermentation include: beer, pickles, olives, some meat prod-ucts, bread, cheese, coffee, cocoa, soy sauce, sauerkraut, and wine. Microorganisms can becomefood, and biotechnology changes the way microorganisms are used.Fermentation is the breakdown of carbohydrate materials by bacteria and yeasts under anaero-bic (without atmospheric oxygen) conditions. The main benefit of fermentation is preservation of theproduct. For example, acid produced may prevent spoilage by some microorganisms. Fermentationmay add flavor-for example, wine. It may remove or alter existing flavors-for example, soy. Or fer-mentation can alter the chemical characteristics of the food as in sugar to ethanol, ethanol to aceticacid, or sugar to lactic acid. To encourage the growth of certain microorganisms, fermentation canbe controlled by pH, salt content, and temperature. Controlling fermentation is an attempt to favordesired organisms. Fermentation is stopped by pasteurizing and cooling. Microorganisms, like SCP, canbecome food. Biotechnology can bring great changes to food production but not without controversy.LEARNING OBJECTIVES &r reading this chapter, the student should be able to: 8 Discuss the use of fermentation in food preservation@ Provide the general reactions for fermentationO Name three methods for controlling fermentationQ List six foods produced by fermentation@ Identifv the uses of acetic acid bacteria and lactic acid bacteria@ Describe fermentation use in bread making@ Identify four uses of acetic acid43 Describe the use of microorganisms as food@ Discuss a role of biotechnology in the food industry

LEARNINGOBJECTIYESObjectivesKey TermsFermentationsUses of FermentationMicroorganisms as Foods


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28 Introduction to Food ScienceGenetic Engineering and BiotechnologySummary

Answers to Review QuestionsI.Describe SCP.SCP s single-celled protein. These microorganisms are selected for their rapid growth,nutritional value, and other properties that make them a good food or feed. Examples ofmicroorganisms used as food or feed include brewer's yeast and baker's yeast

2. Explain fermentation.Fermentation is the breakdown of carbohydrate materials by bacteria and yeasts underanaerobic (without atmospheric oxygen) conditions. It produces acids and alcohols, withsome aldehydes, ketones, and flavorings. Products produced by fermentation help preservefoods against microbial degradation.

3. Show the general reactions that fermentation follows. Glucose-pyruvic acid--+acetaldehyde+ carbon dioxide-alcohol (ethanol) 4. List six foods produced by fermentation.Any six of the following: pickles, olives, some meat products, sour cream, cottage cheese,cheddar cheese, coffee

5. Name three factors that control fermentation.pH, salt content, temperature

6. BST, ,is a growth hormone and is produced by genetically engineered microorganisms. bovine somatotropin

7. Acetic acid produces ;while lactic acid bacteria produce and .Any of the following: beer, wine, whiskey, bread; cheese, chocolate

8. What action does yeast perform in bread making?Yeast performs its leavening fbnction by fermenting carbohydrates such as the sugars,glucose, hc tose, maltose, and sucrose. The principal products of fermentation are capbon dioxide, which produces the leavening effect, and ethanol. Yeast also produces manyother chemical substances that flavor the baked product and change the dough's physicalproperties.

9. became the first genetically engineered product approved for use in food.Renin

10. Define recombinant DNA technology.The process of recombining genes bearing a chosen trait into the DNA molecules of a newhost is called recombinantDNA technology.


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- --- 29nstructor's GuideChapter 14

Food additives (chemicals) are used only to maintain or to improve quality of food or to give it someadded quality that consumers want.

SummaryThe Food and Drug Administration (FDA) monitors the use of additives and allows them to be usedonly if proven information has shown that the additive will accomplish the intended effect in thefood. Also, the amount used cannot be more than is needed to accomplish the intended effect inthe food.Food additives are used to maintain or improve the quality of food. The Food and DrugAdministration (FDA) monitors the use of additives. According to the FDA, additives are any sub-stance intentionally or indirectly a component of food. Intentional food additives include the gener-al categories of flavor, colors, vitamins, minerals, amino acids, antioxidants, antimicrobial agents,acidulants, sequestrants, gums (thickeners), sweeteners, and surface active agents. Some additionaladditives include fat replacers and irradiation. The majority of direct food additives fall into the cat-egory of Generally Recognized AsSafe (GRAS). Unacceptable uses of food additives include any usesto deceive, disguise, lower nutritional value, or avoid good manufacturing practices. For years theuse of food additives has been controlled by the Delaney clause.

LEARNING OBJECTIWS14fter reading this chapter, the student should be able to:@ Describe three reasons for using food additives@ Discuss how food additives are monitored and controlled@ List five general categories of intentional food additives@ Identify the five specific uses of food additives and give examplesO Discuss the use of nutritional additivesQ Identify five uses of food additives that would be considered an abuseO Name two methods used to reduce fat intake49 Identify three color additives exempt from certification@ Read food labels and identify the additives and provide a reason for their use

Lesson OutlineObjectivesKey TermsReasons for UsePreservativesNutritional AdditivesColor Modifiers


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30 Introduction to Food ScienceFlavoring AgentsTexturing AgentsAcidulantsFat ReplacersIrradiationHazardsSummary

Answers to Review Questions1. Name the two methods used to reduce fat intake.

(I) decreasing fat content; (2) using fat replacers, substitutes, extenders, mimetics, or syn-thetic fat2. List three reasons for using food additives.

Any three of the following: To maintain or improve nutritional value; to maintain fresh-ness; to aid in processing or preparation; to make food more appealing3. Using Table 144, choose three additives and describe their function.

Refer to Table 141 (text page 217) for answers. 4. BHT is a/an that retards rancidity of unsaturated oils and prevents browning in fruits

and vegetables.antioxidant

5. Nitrates and nitrites of sodium and potassium add to and maintain in cured meats. flavor; color

6. What organization is responsible for controlling all color additives used on foods in the UnitedStates?Food & Drug Administration (FDA)

7. Why are vitamins and minerals added to foods?To make the foods more nutritious and sometimes to replace those nutrients lost duringprocessing

8. Green potato skins and apple seeds are two examples of common foods containing foodbornetoxicants

9. List five categories of intentional food additives.Any five of the following: Flavors; colors; vitamins; minerals; amino acids; antioxidants;antimicrobial agents; acidulants; sequestrants; gums; sweeteners; surface active agents


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31nstructor's Guide

10. List three colors that are exempt fYom FDA certification.Any three of the following: annatto extract; beta-carotene, beet powder; canthaxanthin;caramel color; carrot oil; cochineal extract; cottonseed flour; ferrous gluconate; h i t uice;$rape color extract; paprika; riboflavin; saffron; titanium dioxide; turmeric, vegetable juice


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Chapter 15PackagingOVERVIEWFood science develops packaging to protect food. The package also serves as a vehicle for the man-ufacturer to communicate with the consumer.

Food packaging development started with humankind's earliest beginnings. Early forms of packag-ing ranged from gourds to seashells to animal skins. Later came pottery, cloth, and wooden con-tainers. These packages were created to facilitate transportation and trade.Using modern technology, society created an overwhelming number of new packages contain-ing a multitude of food products.A modern food package has many functions, its main purpose beingto physically protect the product during transport. The package also acts as a barrier against poten-tial spoilage agents, which vary with the food product. Practically all foods should be protected frommicroorganisms, moisture, and objectionable odors. Consumers rely on the package to offerthat protection.Aside from protecting the food, the package serves as a vehicle for the manufacturer to commu-nicate with the consumer. Nutritional information, ingredients, and often recipes are found on a foodlabel. The package is also used as a marketing tool designed to attract attention at the store. Thismakes printability an important property of a package. Globalization of the food industry and theconsumers are driving the development of innovations in packaging.

LEARNING OBJECTIYESd & r reading this chapter, the student should be able to:63 Identify three types of food packaging@ Name the describe the use of four basic packaging materials8 List ten features or requirements of packaging material@ Describe tests that measure the properties of packaging material@ Identify packages with special features@ Discuss how packaging addresses environmental concernsQ Identify and describe a packaging innovationLesson OutlineObjectivesKey TermsTypes of ContainersFood-Packaging Materials and FormsPackage TestingPackages with Special FeaturesEnvironmental Considerations


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33nstructor's Guide

Innovations in Packaging

Answers to Review Questions1. What are the two basic tests to measure the protective properties of packaging materials? chemical and mechanical 2. Name the three general types of food packaging.

primary, secondary, tertiary 3. Explain the three layers in a retortable package.

The three layers consist of an outer layer of polyester film for strength, temperature resist-ance, and printability; a middle layer of aluminum film for barrier properties; and an innerlayer of polypropylene film that provides for a heat-seal.4. List ten features of packaging materials.

Any ten of the following: Nontoxic and compatiblewith food; sanitary protection; moistureprotection; resistant to impact; light protection; gas and odor protection; ease of openingand closing; tarnper-resistant and tamper evident; pouring features; size, shape, andweight limitations; reseal features; ease of disposal; appearance and printability; trans-parent; low cost5. Name the four basic packaging materials used by the food industry.

metal, plant matter (paper/wood), glass, plastic 6. The collection, separation, and purification of the consumer's disposed food packages is the main problem with

recycling7. Packaging is of concern because of small children and the elderly.

security 8. Packages with special features have what requirements?

being able to withstand freezing and boiling temperatures 9. are an example of edible film packaging.

Sausage casings 10. Describe the functions of primary, secondary, and tertiary packaging.

Primary containers come in direct contact with the food.A secondary container is an outerbox or wrap that holds several primary containers together. Tertiary containers group sev-eral secondary holders together into shipping units.


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Chapter 16 OVERVIEWMilk provides high-quality protein, energy, vitamins, and minerals to human nutrition. Besides fluidmilk the dairy industry produces a variety of milk products including butter, cheeses, condensed anddried products, and cultured products.

Milk is the first food of young mammals. It provides a high-quality protein, a source of energy, andvitamins and minerals. Worldwide, many mammalian species are used to produce milk and milkproducts. Some of these include goats, sheep, horses, and yaks. The focus of this chapter is milk fromdairy cows.Mostmilk in the United States is produced by cows. The dairy industry produces milk as a fluidproduct and in a variety of manufactured products including butter, cheeses, condensed, dry, andcultured.The USDA and the FDA maintain quality standards. To protect the consumer against pathogen-ic microorganisms in milk, it is pasteurized. Butterfat globules in homogenized milk are reduced insize to prevent coalescence. Butterfat is also separated from milk and added back to produce bever-age milk with specific fat content or to be used in the production of butter and creams. Butter is pro-duced by churning butterfat, and a by-product is buttermilk.Concentrated or dried dairy products such as evaporated milk, sweetened condensed milk, con-

densed whey, milk powder, or whey powder increase shelf life and convenience and decrease trans-portation costs. Traditionally, cheese developed as a way to preserve the nutrients of milk. Today,many varieties of cheese have evolved. Production of cheese basically involves the coagulation of themilk and separation of the whey. Coagulation can be accomplished with enzymes, acid, or heat.Yogurt is a fermented dairy product, as are acidophilus milk, sour cream, and kefii. Fermented dairyproducts require a starter culture for fermentation. By legal definition, ice cream contains 10percentor more butterfat. It also relies on sweeteners at a level of l 2 o 16percent.The USDA established grade standards for butter, cheese, and instant nonfat dry milk. The FDAestablished grade designations for fluid milk, yogurt, and cottage cheese. Only officially gradedproducts may carry the grade shield.In an effort to meet new consumer demands, the food industry developed milk and milk productsubstitutes such as coffee whiteners, whipped toppings, imitation milk, and reduced fat products.

LEARNING OBJECTIYES@r reading this chapter, the student should be able to:423 Define the term "milk"@ Describe quality control during the production of milk and milk products@ Explain pasteurization and homogenizationO Identify three methods of pasteurization@ Describe the "solids" composition of milk@ Discuss the separation of butterfat and its usesO List four beverage milk products


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Instructor's Guide

GB Describe butterQ Name five concentrated or dried dairy products@ List the steps in cheese making@ Identify three bacteria used to produce dairy products@ Name five fermented dairy products63 List the steps in making ice creamd Describe three USDA quality grade shields

Lesson OuUineObjectivesKey TermsFluid MilkMilk Products and By-productsQuality ProductsMilk SubstitutesReduced Fat Productssummary

Answers to Review Questions1. heats the milk to at least 16I0Ffor at least 15 seconds. eliminates all viablelife-forms.

Pasteurization, Sterilization2. Name four beverage milk products.

Any four of the following: whole mi& skim milk, low fat milk, buttermilk, acidophilusmilk3.-s made by churning pasteurized cream. Butter d Define "milk."

Milk is a solution containing lactose, water-soluble vitamins (thiamin and riboflavin), andmineral salts. It is also a colloidal dispersion of the protein casein and the whey proteins.Finally, fluid milk is an emulsion with fat globules suspended in the water phase of milk.

5. List the steps in cheese making.1. treatment of milk; 2. additives; 3. inoculation and milk ripening; 4. coagulation;5. enzyme; 6. acid; 7. heat-acid; 8. curd treatment; 9. cheese ripening

6. Why is milk homogenized?Milk is homogenized to prevent the cream portion from rising to the top of the package.

7. Name the three reasons manufacturers use the grade standards.1. Identify levels of quality; 2. Provide a basis for establishing prices at wholesale; 3. Giveconsumers a choice of quality levels


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36 Introduction to Food Science8. List the six areas of inspection that occur at the dairy farm for quality control of milk produc-tion.

heard health, farm water supplies, sanitation of milking equipment, temperature, holdingtimes, bacteria counts of milk

9. After water, what are the components of milk solids?carbohydrates, lactose, fats, proteins, minerals10. Name three dried milk products.

milk powder, whey powder, whey protein concentrates11. LAB or lactic acid bacteria aid in making .

cheese12. List the steps in making ice cream.

1. blending of the mix ingredients;2. pasteurization; 3. homogenization; 4. aging the mix;5. freezing; 6.packaging; 7. hardening


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-- - 37nstructor's Guide

Chapter 17Meat, Poul ry, and EggsOVERVIEWFood science maintains the quality of meat, poultry, and eggs and seeks to provide safe, healthy, andnew foods based on these products.SummaryThe first meat packers in the United States were the colonial New England farmers, who packedmeats in salt as a means of preservation. The beef industry moved from the large metropolitan areasto be near commercial feedlots in the central United States in such states as Texas, Oklahoma,Kansas, and Nebraska. The pork industry remains centrally located in the Midwest, principally inIowa, Illinois, Minnesota, Michigan, and Nebraska, but it is making a move to the west and south-east. Rapid growth and vertical integration characterize the poultry industry.The term "meat" generally refers to the skeletal muscle from the carcasses of animals-beef andveal (cattle), pork (hogs), and lamb (sheep). Inspection takes place at practically every step of thelivestock procurement and meatpacking processes. Grading establishes and maintains uniform trad-ing standards and aids in the determination of the value of various cuts of meat. Carcasses are givenboth a quality and a yield grade. Meat and processed meat products, and other foods of animal ori-gin,provide a complete protein source that contains, in favorable quantities, all the essential animoacids. The most causes of variation in tenderness of beef, pork, lamb, and veal include genetics,species and age, feeding, muscle type, suspension of the carcass, electrical stimulation, chilling rate,aging, mechanical tenderizing, chemical tenderizing, freezing and thawing, cooking, and carving.Poultry includes meat from chickens and turkeys. Meat from chickens and turkeys provides ahigh-quality protein that is low in fat. The protein is an excellent source of essential amino acids.Appearance, texture, and flavor of poultry meat are a primary concern in the food industry and tothe consumer. Poultry meat color is affected by factors such as bird age, sex, strain, diet, intramus-cular fat, meat, moisture content, pre-slaughter conditions, and processing variables. Chickens,turkeys, ducks, geese, guineas, and pigeons are all eligible for grading and certification services pro-vided by the USDA's Agricultural Marketing Service (AMS) Poultry Program's Grading Branch.Although eggs are widely known as breakfast entrees, they also perform in many other ways forthe knowledgeable cook. Eggs are an excellent source of amino acids. The structure and character-istics of an egg include its color, shell, white, yolk, air cell, chalaza, germinal disc, and membranes.Classification is determined by interior and exterior quality and designated by the letters AA, A, orB. In many egg packing plants, the USDA provides a grading service for shell eggs. Food manufac-turers have taken different approaches to reducing the cholesterol in eggs, from physically separat-ing the cholesterol from the yolk to formulating yolks from other products and combining these withthe albumen. Producers are also trying to reduce the cholesterol and change the fat content of eggsby changing the genetics of chickens.LEARNING OBJECTIVES

. .. ... ..... ......................................-- - - - ---- ------------ ---------mr reading this chapter, the student should be able to:@ Describe the production of meat from cattle, pigs, and poultry@ Identify meat products from cattle, pigs, and poultry@ Discuss the general composition of meat and meat products@ List five factors affecting meat tenderness


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38 Introduction to Food Science@ Describe the cooking of meat49 Discuss the production of meat substitutes63 Identify quality grading of meat@ Describe egg productionO Identify factors affecting egg quality@ Discuss egg gradingLesson OutlineObjectivesKey TermsMeat and Meat ProductsMeat SubstitutesPoultryEggsSummary

Answers to Review QuestionsI.The general composition of meat is percent water, percent protein, percent fat, and percent ash (mineral).

70, 21,8, 12. Define what the Contract Acceptance CeMicate ensures.

The contract acceptance service ensures the integrity and quality of poultry and furtherprocessed poultry products bought by quantity food buyers such as food manufacturers,food service operators, and food retailers.3. Who authorizes meat inspection?

Food Safety and Inspection Service h m he USDA4. Why was the development of the extrusion method important in the meat industry?

With the extrusion method, the vegetable protein, combined with flavor, color, and otheringredients, is formed into a plastic mass in a cooker-extruder. Under pressure this mass isforced through a die to form beeflike strips or other shapes characteristic of meats.5. List three general meat by-products.

Any three of the following: cosmetics, glues, tallow, variety meats, meat and bonemeal 6. What are the parts of an integrated meat chicken production company?

Hatching egg production, hatching, growing, processing, and marketing of the birds; oftenthey mill their own feed and render the offal and feathers to produce feed ingredients.7. Explain the difference between a grade AA, a grade A, and a grade B egg.

When cracked onto a surface, a grade AA egg will stand up tall. The yolk is f i i nd thearea covered by the white is small. A large proportion of thick white to thin white exists.


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39nstructor's Guide

When cracked onto a surface, a grade A egg covers a relatively small area. The yolk isround and upstanding. The thick white is large in proportion to the thin white and standsfairly well around the yolk. When cracked onto a surface, a grade B egg spreads out more.The yolk is flattened and there is about as much (or more) thin white as thick white.8. Why are eggs gathered and refrigerated frequently?

The moment an egg is laid, physical and chemical changes begin to reduce freshness. 9. Beef and veal are from ,pork from ,and lamb from .

cattle, hogs, sheep 10. Another word for egg white is .

albumen11. As meat is cooked, contractile become less tender, and becomes more tender.

proteins, collagen12. List the five factors affecting meat tenderness.

Any five of the following: suspension of carcass, electrical stimulation, chilling rate, quali-ty grade, mechanical, chemical, marinading, freezing/thawing, cooking


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- --40 Introduction to Food Science

Chapter 18 sh and She

Fish and shellfish spoil easily, so food science finds ways to process and preserve them to maintainsafety and quality.

Fish and shellfish provide a source of high-quality protein to the diet. Due to the demand and pop-ularity of fish and shellfish, many are commercially cultured and processed. Processed fish andshellfish are checked for quality and graded.Fish includes saltwater and freshwater finfish such as catfish, trout, halibut, salmon, tuna, her-ring, and eel. Shellfish include a group of mollusks and crustaceans like clams, oysters, lobsters,crabs, shrimp, and crayfish. Fish and shellfish are provided by commercial fishing and aquacultureproducers. Fish and shellfish provide a high-quality protein and are also a good source of B vitamins,calcium, phosphorus, iodine, and potassium.Fish spoil easily, so they require strict processing and preservation procedures to maintain qual-ity. Fish processing operations adhere to standards in the Good Manufacturing Practice Code andprocessors use the HACCP method to monitor quality. After inspection, grading determines the qual-ity. GradeA indicates a product of high quality that is uniform in size, free of blemishes and defects,in excellent condition, with good flavor and odor.Fish and shellfish are marketed fresh or frozen. Fish can be marketed as whole, dressed, pan-dressed, filleted, steaks, sticks, or nuggets. Fish protein concentrate or fish flour are fish by-productsused for humans. Roe is fish eggs used for human food also. Surimi represents a new manufacturedproduct made from pieces of fish.

LEARNING OBJECTIYES&er reading this ch a p m the student should be able to:@ Identify three fish and three shellfish used for food8 Describe aquaculture and processing@ Discuss the composition of fish and shellfish@ Identify three spoilage issues associated with fish49 Describe two processes that ensure qualityO List four factors that affect the grading of fish@ List four fish products and by-products43 Describe two methods for preserving fish@ Explain the methods of inspection during processingLesson OutlineObjectivesKey TermsFish, Shellfish, Salt- and FreshwaterFishing versus Culture


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Instructor's Guide 41Composition, Flavor, and TextureSpoilageProcessingPreservationShellfishFish By-productsStorageNew ProductsSummary

Answers to Review QuestionsI.Fish are classified on the basis of their content.

fat 2. Describe the difference between fish and shellfish.

Fish have vertebrae, and shellfish are soft-bodied and have a shell. 3. Fish is a good source of vitamins and , fat, and high-quality .

A, D, unsaturated, protein d Discuss three indications of spoilage in fish.

Any three of the following: skin markings and colors less distinctive; gills change color;scales loosely attached to skin; eyes cloudy and shrunken; flesh separates fkom bones, mayalso become soft and slimy; odor will be fishy5. List the steps for catfish processing.I.receiving and weighing the live fish at the processing plant; 2. holding them alive untilneeded; 3. stunning; 4. deheading; 5. eviscerating; 6. skinning; 7 chilling; 8. size grading; 9.freezing or ice packing; 10. packaging; 11. warehousing; 12. icing; 13. shipping the finishedproduct

6. What does HACCP stand for? Hazard Analysis and Critical Control Point

7. Name the four grading factors for fish. appearance, discoloration, cuttingltrimming defects, improper boning

8. What are the head, gills, and intestines of fish used for? fish meal or fertilizer

9. Caviar is sturgeon preserved in brine. roe

10. List four methods of preserving fish.drying, salting, curing, smoking


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42 htm duct ion to Food Science

Chapter 19Grains, Legumes,and Oi

OVERVIEWCereal grains and legumes supply energy (starch) and protein. As a food, they are consumed asseeds, food science develops techniques to process these seeds into many useM products.

As a food, cereal grains, legumes and oilseeds are consumed as seeds, but more often they are con-sumed in some processed form such as flour, syrup, or vegetable protein extract Corn refining andsoybean extraction provide a wide variety of products for food and technical uses.Cereal grains and legume seeds, and products from these, are used as food for people through-out the world. Cereal grains provide mainly starch and some protein. Legumes provide mainly pro-tein, oil, and some starch. Starch has unique properties that are used in foods. Seeds of the grainsand legumes are used to produce flour. These flours are used to produce a variety of other food prod-ucts.Corn refining and soybean extraction separate the corn seed and soybeans, respectively, intocomponent parts and convert these to high-value products. These processes are some of the bestexamples of value added agriculture and the application of food science.

LEARNING OBJECTIYES&r reading this chapter, the student should be able to:O Diagram the general structure of a grain@ Name three cereal grains@ Describe the general composition of grains, legumes, and oilseeds@ Identify three properties of starchQ List four factors that must be controlled when cooking starch8 Discuss the milling of grain to flour@ Identify five types of wheat flour43 Explain the classes of wheat and grades of flour@ Identify the type of flours other than wheat flour@ List the steps in corn refining63 Name four products derived fi-om corn@ Explain the processes that take place during bakingQ List four oilseeds and indicate the use of their products@ Discuss the general use of legumes(B Name four general categories of products &om soybean extraction@ Identify five food products of soybean extraction


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Instructor's Guide

Lesson OutlineObjectivesKey TermsCereal GrainsStarchMilling of GrainsCorn RefiningBreakfast CerealsPrinciples of BakingLegumesSoybeanss-=YAnswers to Review Questions1. Explain the processes that take place during baking.

Liquid serves as a solvent for salt, sugar, and other solutes; assists in the dispersion of allthe colloids and suspensions; assists in the development of gluten; and contributes to boththe leavening and gelatinization phenomena during baking. Sugar facilitates air incorpo-ration by shortening, inhibits development of gluten and gelatinization of starch, and ele-vates the temperature at which egg and flour proteins heat denature.Eggs contribute to thestructure of a baked product The leavening source used in a baked product may serve toproduce gas by physical, chemical, or biological methods. Salt functions to control yeastmetabolism in yeast bread.2. Soy is made from roasted soybeans in a fine powder. Soy are substitutes forcream cheese or sour cream. Soy is a dark brown liquid made from soybeans that have

been fermented. Soy comes from defatted soy flakes.flour, cheeselyogurt, sauce, protein concentrate3. List three properties of starch.

Any three of the following: completely insoluble in cold water; on cooking, a colloidal dis-persion is formed in the resulting starch paste; some pastes form gels and some are non-gelling; some are opaque and some are clear, semiclear, or cloudy in appearance and softor cohesive in texture; some tend to become rigid on standing; some are cohesive and tendto be stringier4. Name five types of wheat flour.

enriched, bread, cake, all-purpose, pastry5. List four general uses of legumes.

Any four of the following: fermented foods, flours, imitation meats, infant formulas, oils,and sprouts6. The is the large central portion of the kernel and contains most of the starch. The is the small structure at the lower end of the kerneL It is rich in fats, proteins, and minerals.

endosperm, germ


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44 Introduction to Food Science7. Identify five food products of soybean extraction.

Refer to Table 19-2 (text page 346) for answer.8. What is the purpose of the first step of corn refining-steeping?

During steeping, the kernels absorb water, increasing their moisture levels from 15 percentto 45 percent and more than doubling in size. The corn swells and softens. The mild acid-ity of the steepwater begins to loosen the gluten bonds within the corn and release thestarch.

9. List four factors that must be controlled when cooking starch.Any four of the following: temperature of heating; time of heating; intensity of agitation orstirring; pH of the mixture; addition of other ingredients

10. Name four products derived fkom corn.Any four of the following: organic acids, amino acids, vitamins and food gums, citric andlactic acid, ethanol, dextrose, high-fiuctose corn syrup, feeds for animals, vitamins C andE, monosodium glutamate, xanthan gum


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Instructor3 Guide 45

Chapter 20s and Vege

OVERVIEW-................................................. ................. .. .Fruits and vegetables include a wide variety of edible parts. Food science seeks to maintain the qual-ity and safety of fresh fruits and vegetables, and to develop new, safe, healthy food products fromfruits and vegetables.SummaryFruits, vegetables, and other plant tissues either directly or indirectly supply all foods to humans. Anestimated 270,000 plant species exist. The number of crops that fit into humans' dietary picture isprobably between 1,000 and 2,000 species. Fruits and vegetables take in a wide variety of edible plantparts. Fruits include apples, pears, peaches, apricots, plums, cherries, bananas, oranges, tangerines,and grapes. The term vegetable includes many different parts of plants, including some fruits.They vary widely in carbohydrate and protein content. Many have a high water content. Fruitsand vegetables are a good source of many vitamins and minerals. Because many parts of plants areeaten as fruits or vegetables, an understanding of plant tissues is critical to food scientists.Harvesting of fruits and vegetables can be affected by variety, soil type, water, temperature, andseason. Climacteric fruits produce ethylene gas during ripening; nonclimacteric fruits do not. Fruitsand vegetables get their characteristic color from numerous pigments. In general, water transport inplant tissues influences the texture of fruits and vegetables; flavors and aromas are due to com-pounds such as aldehydes, alcohols, ketones, esters, organic acids, and sulfur compounds.

The USDA assigns quality grades to both fruits and vegetables. These quality grades determinethe eventual use of the fruit or vegetable. Post-harvest care is critical to maintaining the optimalquality of fruits and vegetables. Fruits and vegetables are sold fresh, canned, and frozen. Most ofthese processes are automated. By-products from fruit and vegetable processing are often used forlivestock feed. Biotechnology offers the promise of providing h i t s and vegetables to meet new con-sumer demands.LEARNING OBJECTIVESmr reading this chapter, the student should be able to:@ Identifv the parts of a plant considered a vegetable or a fruitQ Describe the nutrient composition of a fresh fruit or vegetable68 Discuss the structure of a plant cell8 Describe the plant tissues and their hnctions@ Explain climacteric and nonclimacteric with examples@ Name one pigment in fruits or vegetables and describe how it responds to heat or pH@ List four factors affecting the texture of fruits or vegetables8 Name four general compounds that give fruits and vegetables their flavor8 Identify the quality grades for fruits and vegetables@ Describe how quality grade determines the use of a fruit or vegetable@ List five factors considered during storage@ Describe the processing of fruits43 Discuss the processing of vegetables


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46 Introduction to Food ScienceLesson Outline0bjectivesKey TermsGeneral Properties and Structural FeaturesGeneral CompositionActivities of Living SystemsHarvestingPos t-harvesProcessing of FruitsProcessing of VegetablesBy-productsBiotechnologySummary

Answers to Review Questions1. F'ruits and vegetables get their characteristic color from .pigments2. What are the grade designations for fresh fruits and vegetables and

Instructors Guide for Food Science

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