DRAFT ONLY Biotechnology and nanotechnology Foundation 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.
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Biotechnology is the industrial use of biological processes to make products.
Its major uses are in the production or preservation of food.
For many centuries the process 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 alcohol or to lactic acid by enzymes in the micro-organisms.
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 production;
• consumer demand for convenient, high quality products at reasonable cost.
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 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).
Cheese – rennet (from the enzyme 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.
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.
Every cell in plants and animals, including humans, contains genes.
They are inherited 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 pork with more muscle and less fat.
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 led 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 varieties of crops or livestock by introducing 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 give a higher yield;
• animals may be made more resistant to disease, produce less fatty meat, grow faster or be more fertile.
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 genetic modification could harm the environment and pose a danger to humans.
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 needed 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.
Food is labelled if it contains genes that would not be expected 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.
Food from genetically modified 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 derived from any animal.
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 packaging.
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).
Recent technological developments lead the way for the manufacture 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 carbohydrate particles which bind with bacteria so they can be detected and eliminated.
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).
Nanotechnologies are not new – chemists have been making polymers based on nanoscale subunits for many years.
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 flavour of a food can be changed with bitter blockers or sweet and salty enhancers.
Nano-enhanced bacteria keep oxygen sensitive foods fresher.
Certain concerns have been raised in regard to the safety of the consumer resulting from a growing body of scientific evidence, which indicates 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 drink are largely unknown.
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 the 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.
For more information visit www.nutrition.org.ukwww.foodafactoflife.org.uk