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Modern Food Materials. These icons indicate that detailed teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates the slide contains activities created in Flash. These activities are not editable.
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Modern Food Materials These icons indicate that detailed teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates the slide contains activities created in Flash. These activities are not editable. This icon indicates the slide contains activities created in Flash. These activities are not editable. For more detailed instructions, see the Getting Started presentation. For more detailed instructions, see the Getting Started presentation.
Modern food materials Food companies spend millions of pounds each year developing new food products. Food science can make food that is better for the people who eat it. Leave our food alone, you're only in it for the money. Let's look at some examples to help you decide what you think.
New protein foods Lots of development is going on into sources of protein that don’t involve animals, either for economic reasons or because some people do not want to eat animal products. New protein foods, like tofu, texturized vegetable protein and Quorn are often lower in fat than meat, and a good source of protein.
Probiotic products • Whilst some bacteria can make us ill, other can help us digest our food. • Probiotic products claim to contain ‘friendly bacteria’ which will help us digest our food better. • They are often supplied as yoghurts and drinks. • There are lots of beneficial health claims made by probiotic food companies. However, more research still needs to be done to prove some of the claims.
Phytochemicals – chemicals from plants • Phytochemicalsare biologically active nutrients. • They occur naturally in fruit and vegetables giving them theirscent,flavourandcolour. • Research shows they may also be useful in protecting againstdiseaseslike cancer and heart disease.
Antioxidants – what are they? • Antioxidantsstop substances in foods from combining with oxygen. • When oils and fats oxidise they becomerancid. They smell and taste unpleasant and are a health risk. • Vitamins C and Eare antioxidants that occur naturally, and so is beta carotene. Other antioxidants are man made. • Antioxidants are examples of phytochemicals. Vitamin C is found in green leafy vegetables, like these cabbages, potatoes, citrus fruits, strawberries, peppers and tomatoes.
Antioxidants – why are they useful? • Oxidation is linked to the aging process, like the formation of wrinkles. • It is also involved in some diseases such as arthritis, cancer and cataracts. • Free radicals formed by oxidation make cholesterol sticky, and then it can block arteries. • Eating lots of fruit and vegetables will give you natural antioxidants. • Adding antioxidants to other foods may also help fight these diseases.
Modified starches • Modified starches are normal starches that have been altered chemically or physically in some way. • Starches have always been used to thicken foods, for instance corn flour is used to set flavoured milk to make a blancmange. When milk is heated to boiling point, the starch grains swell and the blancmange thickens. • Granular starches have now been developed that swell in cold water, and so can be used to set desserts instantly.
Other uses of modified starches • Oxidised starches produce tough, clear films that make products like fish coatings and french fries crispier. • They are also added to some breakfast cereals so they stay crisp after you add the milk. • Re-dried starches have less moisture than ordinary ones and are used to dust sweet moulds to stop the sweets sticking. • Modified starches are also used in many low fat products. Theyimprove the melting and stretching of imitation mozzarella cheese and also its flavour. Mozzarella Or Modified Starch?
Genetically modified foods Life savers or Frankenstein foods? You decide.
What are GM foods? • All living things are made up of genetic material. • Nature has always changed the genetic properties of living things by mutation and natural selection. • Now modern scientists can change the genetic make up of cells to change their properties. • For example, genetic engineering could allow certain characteristics of wild wheat to be transferred to wheat grown as a crop to make it more resistant to disease.
How are foods genetically modified? • Scientists use chemical ‘scissors’ to obtain the DNA or gene they want to transfer. It could come from an animal, a plant or bacteria. • They then place it into a plant cell. • The DNA then gets into the nucleus of the plant, and new cells grow from the altered ones to make plants with the new characteristics. • The DNA will have been chosen to pass on the feature they want the new plant to have. Gene taken from bacterium that produces a natural insecticide Wheat that does not need to be sprayed against insects Added to wheat cells
Why are foods genetically modified? • Some genetic engineering is done for economic reasons – the crop will grow bigger or faster and so make more money. • GM crops may be useful to poorer countries if they need less water, or are more resistant to pests and diseases. • Some genetic research is for medical developments such as new vaccines or cancer treatments. • It may be possible to make biodegradable plastics from plants to reduce the amount of fossil fuel we use and help the environment. Tomatoes, modified to contain three times the normal amount of vitamin A, may help prevent cancer, scientists claim.
Genetically modified enzymes • Enzymes are proteins that speed up chemical reactions such as digesting food. • Chymosin is an enzyme extracted from the stomach of calves which is added to milk as rennet to make cheese. • An equivalent enzyme can be made from genetically modified micro-organisms such as yeast. • This means the cheese that is produced is suitable for vegetarians and as a result fewer calves are slaughtered.
