Biotechnology and nanotechnology.ppt

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1、Biotechnology and nanotechnology,Foundation,DRAFT ONLY,Learning objectives,To define biotechnology and nanotechnology. To understand where increases in the use of biotechnology and nanotechnoogy have occurred. To understand areas of traditional biotechnology. To understand areas of modern biotechnol

2、ogy. To know the food labelling legislation about genetically modified food products.,What is biotechnology?,Biotechnology is the industrial use of biological processes to make products.Its major uses are in the production or preservation of food.,Biotechnology is not new.,For many centuries the pro

3、cess of fermentation has used micro-organisms (yeasts and bacteria) to make beer, yogurt and cheese. Bread making, beer brewing and pickling all use naturally occurring micro-organisms in the production of food and drink.The basis of the fermentation process is the conversion of glucose (sugar) to a

4、lcohol or to lactic acid by enzymes in the micro-organisms.,Increases in biotechnology,Increases in the use of biotechnology by the food industry are due to: competition between food companies for an increased market share; attempts to increase efficiency and reduce the environmental impact of produ

5、ction; consumer demand for convenient, high quality products at reasonable cost.,Traditional biotechnology,Traditional biotechnology mainly involves the production of foods, such as cheese, bread and wine.The fermentation process: offers a method of preservation, e.g. by producing acid which lowers

6、the pH (converting a perishable food into one that has a longer shelf-life); can be used to change the nutritional value of food products, e.g. converting milk to cheese; can create or improve sensory characteristics of foods (flavour, aroma and texture).,Food production,Cheese rennet (from the enzy

7、me renin) is used to coagulate milk, forming curds and whey.Alcoholic beverages glucose is fermented by yeast enzymes.Bread enzymes within the flour break down starch, eventually producing glucose. This is fermented by enzymes present in yeast producing alcohol and carbon dioxide.,Modern biotechnolo

8、gy,The emphasis of modern biotechnology is on the production of raw materials and food ingredients. Work is based on changing the characteristics of plants, animals and micro-organisms, including fungi.,Cell genetics,Every cell in plants and animals, including humans, contains genes.They are inherit

9、ed from each parent and passed on to future generations. They carry information about physical characteristics and qualities.In the past, plant and animal breeders have had to work through many generations, and so wait for years for improvements to be achieved, e.g. cross breeding pigs to produce po

10、rk with more muscle and less fat.,Deoxyribonucleic acid,Scientists, now, are able to identify which individual gene controls a particular characteristic. These discoveries offer a quicker and more exact way to improve crops and livestock.Understanding the nature of deoxyribonucleic acid (DNA) has le

11、d the way to genetic modification. This is the process by which biotechnologists can selectively splice specific sequences of DNA genes together, to produce a crop, for example, with additional or improved characteristics.,Improving crops and livestock,Improving varieties of crops or livestock by in

12、troducing or modifying specific genes is fast and more accurate than traditional breeding. If the gene can be identified and modified the following changes may be possible: plant crops may have a longer shelf-life, be more resistant to pests or disease, be more nutritious, have a better taste or giv

13、e a higher yield; animals may be made more resistant to disease, produce less fatty meat, grow faster or be more fertile.,Genetic modification,A number of ethical and safety issues need to be considered with genetic modification. Some concerns expressed by consumers include fears that the results of

14、 genetic modification could harm the environment and pose a danger to humans.,Genetically modified (GM) food,Foods which have been produced from genetically modified organisms (GMOs) are likely to appear no different from food produced by traditional means.A series of laboratory tests would be neede

15、d to show that genes had been changed.The Government has set up a series of controls to protect consumers, the environment and people who work with genetically modified organisms (GMOs) which take account of these concerns.,GM food labelling,Food is labelled if it contains genes that would not be ex

16、pected to be there and which might cause concern to some people on ethical grounds.Labelling is not considered necessary for foods in which the inserted gene has been destroyed by processing, and is therefore not present in the food at the time it is sold.,GM food labelling,Food from genetically mod

17、ified organisms needs to be labelled if: if contains a copy gene originally derived from a human being; if contains a copy gene originally derived from an animal which is restricted by some religions, e.g. pigs for Muslims or Jews; it is a plant or microbial food and contains a copy gene originally

18、derived from any animal.,What is nanotechnology?,Nanotechnology is the manufacture and use of materials and structures at the nanometre scale (a nanometre is one millionth of a millimetre). It offers a wide range of opportunities for the development of innovative products and applications for food p

19、ackaging. Nanotechnology and nanomaterials are a natural part of food processing and conventional foods, because the characteristic properties of many foods rely on nanometer sized components (such as nanoemulsions and foams).,Nanotechnology,Recent technological developments lead the way for the man

20、ufacture of nanoparticles to be added to food. These could be finely divided forms of existing ingredients, or completely novel chemical structures.Nanotechnology applications in the food sector are on the increase worldwide and are expected to grow rapidly in the future, e.g. the use of nano carboh

21、ydrate particles which bind with bacteria so they can be detected and eliminated.,Nanotechnology,The types of material produced can be at the nanoscale in one dimension (very thin coatings), two dimensions (nanowires) or three dimensions (nanoparticles, such as a very fine powder preparations). Nano

22、technologies are not new chemists have been making polymers based on nanoscale subunits for many years.,Uses for nanotechnology in food,The texture of food can be changed as food spreadability and stability (nanoemulsions) improve with nano-sized crystals and liquids for better low fat foods.The fla

23、vour of a food can be changed with bitter blockers or sweet and salty enhancers.Nano-enhanced bacteria keep oxygen sensitive foods fresher.,Issues and concerns,Certain concerns have been raised in regard to the safety of the consumer resulting from a growing body of scientific evidence, which indica

24、tes that some free nanoparticles may cause harm to biological systems because they can penetrate cellular barriers, and induce oxyradical generation that may cause oxidative damage to the cell. However, the nature and extent of risk to consumer health from ingestion of nanoparticles via food and dri

25、nk are largely unknown.,Assessment of novel foods,The Food Standards Agency is the UK body responsible for the assessment of novel foods and it will not assess the safety of using nanotechnology in the food chain unless asked to do so.There are no specific criteria to consider particle size under th

26、e novel Foods Regulation. However, the assessment of the food, or food ingredient includes details of composition, nutritional value, metabolism, intended use and the level of microbiological and chemical contaminants.,Review of the learning objectives,To define biotechnology and nanotechnology. To

27、understand where increases in the use of biotechnology and nanotechnoogy have occurred. To understand areas of traditional biotechnology. To understand areas of modern biotechnology. To know the food labelling legislation about genetically modified food products.,For more information visit www.nutrition.org.uk www.foodafactoflife.org.uk,