Chapter 1. Food Biotechnology for undergraduate students.pptpptx

A teaching note on food biotechnology for undergraduate students

1. Arba Minch University College of Natural Sciences Department of Biology Food Biotechnology ( Biot. 4135) By: Samson Tizazu (MSc) Oct. 2016 1

2. Course Outline Introduction Food Industry Food Microbiology Genetically Modified Food Current Trend of Food Processing and Consumption 2

3. Chapter One 1.1 Introduction Food : Any substance that is/can be consumed by living organisms, in order to sustain life Q. Name 3 foods that come from things that have not been alive ? Man has been exploiting living systems for the production of food for centuries. Classical plant and animal breeding and selection of superior strains are well-accepted practices for improving the food production system. To produce a wide variety of fermented foods, such as cheese, bread, beer and, wine 3

4. 1.2 Famine and Hunger Famine: a period of extreme shortage of food in a region Hunger: A need or compelling desire for food Famine is extreme shortage of food in a region while, hunger is a need or compelling desire for food Young children & babies are often the first to die , due to food shortage Extreme malnutrition in children reduces school performance and causes long-term brain damage The provision of proper nutrition and food security is central to achieving many of the Millenium Development Goals, such as: Reducing poverty and child mortality Improving maternal health Combating disease. 4

5. Cause and Solutions: Causes: Poverty Agricultural mismanagement C onflict Unfair trade rules Problems of HIV/AIDS Climate change Solutions (Tackling root causes): Building capacity and reducing the risks of corruption Effective agricultural policies that involve and prioritise smallholders, pastoralists, and women. Investing in the rural poor Consolidate fragile peace deals, that provides peaceful livelihoods Utilizing the enormous potential of biotechnology to end hunger 5

6. 1.3 Food Science Definitions: Is the understanding and application of science to satisfy the needs of society for sustainable food quality, safety and security Is the application of the basic sciences and engineering to study the fundamental physical, chemical, and biochemical nature of foods and the principles of food processing The fundamental biological, chemical and physical scientific principles associated with the study of foods 6

7. Sub-disciplines of food science Food Chemistry: Covers the basic composition, structure and properties of foods and the chemistry of changes occurring during processing and utilization Food Engineering: Involves study of engineering concepts and unit operations used in food processing . Engineering principles should include: material and energy balances thermodynamics fluid flow mass transfer Product Development: The invention of new food products Sensory Analysis: The study of how food is perceived by the consumer’s senses 7

8. Cont… Food Microbiology: is the study of microbial ecology related to foods: the effect of environment on food spoilage and food manufacture, the physical, chemical and biological destruction of microorganisms in foods , the microbial examination of food stuffs, public health and sanitation microbiology Food Biotechnology: the use of genetic engineering techniques to create foods with desirable traits, such as resistance to pests Food Processing: covers general characteristics of raw food materials, principles of food preservation, processing factors w/c influence quality, packaging, water and waste management, good manufacturing practices sanitation procedures 8

9. 1.4 Food Technology Definitions: Is the use of the information generated by food science in the: selection, Preservation Processing Packaging and distribution of foods. Food technology affects the consumption of safe, nutritious and wholesome food The food scientist analyses and takes apart food materials, whilst the food technologist puts all that knowledge into use in producing safe, desired food products 9

10. Early History and Recent Development in Food Technology We have used science and technology for thousands of years to help provide adequate food The progression from hunter-gatherer to agriculture led to the need to store and preserve foods Without some form of processing, foods deteriorate rapidly due to the action of micro-organisms and enzymes Technology has allowed advances in food processing, such as freeze drying and introduced ‘new’ food ingredients, such as: Textured Vegetables Protein (TVP) Myco -protein The use of biotechnology and nanotechnology is increasing 10

11. Cont… Greater consumer awareness of nutrition, diet and health has led to new areas of food manufacture The formulation of food products with modified nutritional composition, for example: low fat spreads low fat dairy products low calorie drinks Genetic modification of ingredients has also been increasing Concern for the welfare of animals and humans in food production have also influenced the types of foods available and how they are produced 11

12. Early methods of processing and preservation Using chemicals: Salting meat Sugar to make jam S toring in alcohol Temperature control: S un drying fruit; U sing ice blocks. 12

13. There have also been many technological changes in the home: Refrigerators became widely used from the mid-1950s; Domestic freezers in the 1970s; Microwave ovens in the 1980s. Frozen and microwavable food and ready meals followed these developments . 13

14. Some of these early methods of food processing and preservation are still used today. New technologies have given us a greater range of methods to package and store foods This enables the preservation of nutrients and the extension of food product shelf-life . In recent years demand has increased for minimally processed foods which retain their freshness. New techniques have replaced methods that rely on heating and drying Advances in Food Technology 14

15. Cont… Food Biotechnology will allow more food to be produced on less land Economic benefits will allow food biotechnology to contribute to global hunger Biotechnology increases the amount of food that can be produced on the same amount of land. Vitamin A deficiency and iron deficiency afflict millions worldwide 15

16. What are the different techniques associated with food biotechnology? Food biotechnology techniques are often divided into old and new Old: Older food biotechnology techniques include conventional crossbreeding which refers to the random recombination of genes through sexual reproduction leading to a new organism with improved traits Crossbred plants, for instance, may require several generations to achieve a particular trait due to the randomness of gene transfer. Examples of such traits are: improved crop yield, aesthetic qualities, increased tolerance to physical stress such as cold temp. increased resistance to disease and insects. 16

17. New Modern food biotechnology techniques include the joining of two pieces of DNA from different organisms Specific genes are transferred from one organism to another in order to improve the nutrient levels of a food Modern techniques are much faster and more precise. It is possible to quickly transfer a specific gene of interest rather than waiting on the random shuffling of genes over several generations. 17

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19. THE END ! 19

20. Chapter 2 Food Industry 2.1. Unit Operations in Food Industrial Processing Is an attempt to combine all forms of physical processing into a small number of basic operations, which are called unit operations. Food processes may seem bewildering in their diversity, but careful analysis will show that these complicated and differing processes can be broken down into a small number of unit operations. For example, consider heating of which innumerable instances occur in every food industry. There are many reasons for heating and cooling - for example, the baking of bread, the freezing of meat, and the frying of yam slices in oils . But in processing , the prime considerations are firstly, the extent of the heating or cooling that is required and secondly, the conditions under which this must be accomplished. Thus, this physical process qualifies to be called a unit operation. 20

21. Food Processing Series of physical processes that can be broken down into simple operations These operations can stand alone 21

22. Unit Operations 1. Material Handling 2. Cleaning 3. Separating 4. Size reduction 5. Fluid Flow 6. Mixing 7. Heat transfer 8. Concentration 9. Drying 10. Forming 11. Packaging 12. Controlling 22

23. 1. Materials Handling Includes : Harvesting, refrigerated trucking of perishable produce, transportation of live animals, conveying a product from truck or rail car to storage During these operations: Sanitary conditions must be maintained Losses minimized Quality maintained Bacterial growth minimized Transfers and deliveries must be on time while keeping time to a minimum for efficiency and quality Trucks, trailers, harvesting equipment, railcars , a variety of conveyors, forklifts, storage bins, & pneumatic lift systems are all part of the process 23

24. 2. Cleaning Ranges from dirt removal to the removal of bacteria from liquids Uses: Brushes High-velocity air Steam Water Vacuums Magnets Microfiltration Mechanical separation Method used depends on the food surface Equipment and floors and walls of the facility also require frequent, thorough cleanings to maintain product quality 24

25. 2. Cleaning Cleaning is the unit operation in which contaminating materials are removed from the food and separated to leave the surface of the food in a suitable condition for further processing. Peeling fruits and vegetables, skinning meat or descaling fish may also be considered as cleaning operations. In vegetable processing, blanching also helps to clean the product. The presence of contaminants (or foreign bodies) in processed foods is the main cause of prosecution of food companies. Cleaning should take place at the earliest opportunity in a food process both to prevent damage to subsequent processing equipment by stones, bone or metals, and to prevent time and money from being spent on processing contaminants which are then discarded 25

26. 3. Separating Achieved on the basis of density or size and shape Density based separations include: Cream from milk Solids from suspension Removal of bacteria from fluid 26

27. 3.1 Cream Separator Disc type centrifuge Separates the milk into low and high density fluid streams, permitting the separate collection of cream and skim milk 27

28. 3.2 Clarification Done with a clarifier-a disc type centrifuge that applies forces of 5,000-10,000 times gravity and forces denser materials to the outside Used to remove sediment and microorganisms Allows solids to be removed Used to recover yeast cells from spent fermentation broths and to continuously concentrate bakers cheese from whey 28

29. 3.3 Membrane Processes Uses membranes with varying pore sizes to separate on the basis of size and shape Reverse osmosis Uses membranes with the smallest pore and is used to separate water from other solutes Requires a high pressure pump Ultra filtration Uses membranes with larger pores and will retain proteins, lipids and colloidal salts while allowing smaller molecules to pass through to the permeate phase Requires a low pressure pump Microfiltration Pores less than 0.1 microns are used to separate fat from proteins and to reduce microorganisms from fluid food systems Requires a low pressure pump 29

30. 4. Size Reduction Uses high-shear forces, grater, cutters, slicers, homogenizers, ball mill grinders Size reducers used for meat include Grinders, Bacon slicers, sausage stuffers, & vertical choppers Better thought of as size adjustment because size can be reduced or it can be increased by aggregation, agglomeration or gelation 30

31. 5. Pumping (Fluid Flow) Achieved by either gravity flow or through the use of pumps Gravity flow Flow is laminar and is transferred from the fluid to the wall between the adjacent layers Adjacent molecules don’t mix Pumps Centrifugal pump uses a rotating impeller to create a centrifugal force within the pump cavity. The flow is controlled by the choice of the impeller diameter and rotary speed of the pump drive. The capacity of a centrifugal pump is dependent upon the speed, impeller length and the inlet and outlet diameters Positive Pumps consist of a reciprocating or rotating cavity between two lobes or gears and a rotor. Fluid enters by gravity or a difference in pressure, and the fluid forms the seals between the rotating parts. The rotating movement of the rotor produces the pressure to cause the fluid to flow. 31

32. 6. Mixing Two major purposes Heat transfer Ingredient incorporation Different mixer configurations are used to achieve different purposes Efficiency depends on Design of impeller Diameter of impeller Speed Baffles 32

33. 7. Heat Exchange Used for either heating or cooling to Destroy microorganisms, produce a healthful food, prolong shelf-life through destruction of enzymes and promote products with acceptable taste, odor and appearance 33

34. 7.1 Factors that Influence Heat Transfer Heat Exchanger Design Heat Transfer properties of the product Specific heat Thermal conductivity Latent heat Density Method of Heat Transfer Conduction Radiation Convection Viscosity 34

35. 7.2 Types of Heat Exchanges Used In the Food Industry Plate Pass fluid over a plate where heating or cooling medium is being passed up and down on the other side of the plate Most efficient method of heating fluids with low viscosity Tubular Composed of a tube within a tube in which product and heating or cooling medium are flowing in opposite directions . Low cost Used for fluids of higher viscosities Swept Surface Have blades that scrape the surface of the heat exchanger and bring new product continuously to the heat or cooling surface Used for fluids of very high viscosity Example: Ice Cream Freezer 35

36. 7.3 Common Unit Processes that Include Heat Transfer as a Unit Operation Pasteurization ( heat) Sterilization ( heat) Drying ( heat) Evaporation ( heat) Refrigeration ( cold) Freezing (cold) 36

37. 8. Concentration Achieved through evaporation and reverse osmosis Often used a pre-step to drying to reduce costs 37

38. 9. Drying 3 methods Sun or tray Spray freeze 38

39. 9.1 Sun or Tray Drying Least expensive Used with products that are already solid like fruits and vegetables Drying is achieved through exposure to the sun or a current of warm or hot air Used to make grapes into raisins 39

40. 9.2 Freeze Drying Used with heat sensitive products Moisture is removed without a phase change Commercially only instant coffee is widely freeze dried 40

41. 9.3 Spray Drying Most common Used for fluid products 41

42. 10. Forming Processes Compacting Pressure Extrusion Molds Powders & binding agents Heat and pressure Extrusion cooking Used for Hamburger patties, chocolates Jellies, tablets, butter, sausages, Variety breads, margarine bars, cheeses 42

43. 11. Packaging Machines operate at high speeds and automatically package food products in a step-wise and automated fashion from forming the container, filling the container, sealing the container, labeling and stacking it Use a variety of materials 43

44. 12. Controlling Tools include Valves Thermometers Scales Thermostats Other instruments to control pressure, temperature, fluid flow, acidity, weight, viscosity, humidity, time and specific gravity All automated 44

45. Conserving Energy Energy intensive Energy represents a significant share of the costs of the final product Food processors are always looking for new ways to optimize energy use Energy requirements are monitored and new and more efficient ways are continually looked for Examples: Heat that is used or removed is captured and used somewhere else in the process 45

46. New Processes Major goal of food scientist and food processing engineers Always looking to improve quality and/or increase efficiency 46

47. Summary Material handling, cleaning, separating, size reduction, fluid flow, mixing, heat transfer, concentration, drying, forming, packaging and controlling are the units that make up food processing Most processing involves a combination or overlap of these units of operation When they do overlap complex controls ensure the proper function or each operation 47

48. END 48

49. 2.2. Food processing 2.2.1 Backing bread 49

50. Description, composition and nutritional value of fruit and vegetables 50

51. Various products of fruits and vegetable processing Industrial process steps of fruit and vegetable ??? 51

52. 2.2.4. Dairy Industry 52

53. 2.2.5. Meat Processing technology 53

54. 2.2.5.1.Effect of animal growth on meat quality 54

55. 2.2.5.2. Hazards in meat processing 55

56. 2.2.5.3. Facility requirement for meat processing 56

57. 2.2.5.4.Type and criteria for meat processing technology 57

58. 2.2.6. An over view of beverage industries 58

59. 2.2.7. Oil and Fat Processing Industry 59

60. 2.2.7.1.Type of extraction methods 60

61. 2.2.7.2.Butter, Ghee and Margarine Processing 61

62. 2.2.7.3.The hydrogenation of Oil 62

63. 2.2.7.4.Handling and storage of oil-bearing material 63

64. 2.2.7.5.Preparation oil bearing materials 64

65. Chapter 3: Food Microbiology 3.1. History and development of food microbiology 65