Food Preservation


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Food Preservation

  2. 2. VARIOUS WAYS OF FOOD PRESERVATIONBottling and Salting Waxing Smokingcanning Vacuum Pickling Boiling packing Cooling Pasteurizatio Drying and n freezing
  3. 3. BOTTLING ANDCANNING Bottling and canning are processes of preserving food by heating and then sealing it in an airtight container. The food is boiled to kill microorganisms and then sealed to prevent other microorganisms from getting in.
  4. 4. PICKLING Picklingfood in vinegar or other acids, makes it difficult for microorganisms to live. Commonly pickled food include onions, parkias, soya beans and chillies.
  5. 5.  Sugar can also be used in pickling fruits such as nutmegs, mangoes and cherries. The concentrated sugar solution used draws water from the fruit thus preventing the growth of microorganisms.
  6. 6. DRYINGA lot of food is preserved by drying under the sun. Drying removes most water from food. Most bacteria die or become inactive when the food is dried.
  7. 7.  Anchovies and dried chillies are examples of dried food. A lot of fruit such as raisins, guavas and papayas can be eaten dried.
  8. 8. SALTING Salting is an age-old way of preserving food. The salt draws out moisture and prevents microorganisms from growing. In this process, food such as fresh fish are gutted, washed and coarse salt is rubbed into it.
  9. 9. Alot of our local foods are preservedby salting process.
  10. 10. VACUUM PACKING Vacuum packing keeps food by sucking air out from its packaging. Foodis thus prevented from spoiling because there is no air.
  11. 11.  Vacuum packing is commonly used for storing nuts, sliced fish, pickled and dried fruit.
  12. 12. COOLING ANDFREEZING Cooling and freezing are the most common forms of food preservation.
  13. 13.  Cooling slows down the action of microorganisms, thus it takes longer to spoil. It allows fruit from different parts of the world to appear on our supermarket shelves. At freezing temperature, microorganisms become inactive, thus food cannot spoil when it is frozen.
  14. 14.  Food like meat, fruit and vegetables are kept in the refrigerator.
  15. 15. WAXING Waxing of fruit and vegetables is also common. Apples, oranges, eggplants and tomatoes are dipped into liqiud wax to prevent growth of fungi and loss of moisture.
  16. 16. BOILING Asfood is heated and cooked, the heat kills the microorganisms. Boiling kills most bacteria. However, those not affected by heat will grow when the conditions are suitable.
  17. 17. PASTEURIZATION Pasteurization means heating food to a certain temperature for some time followed by rapid cooling. Heating at such high enough temperature kills most bacteria. However, it does not affect the taste and nutritional value of the food.
  18. 18.  Fresh milk, yoghurt drink and juices are pasteurized to make them last longer.
  19. 19. SMOKING Smoking is the process of drying food with smoke for a long period of time. This method is mainly used for fish, meat and fruit such as banana. The drying effects of smoke and the chemicals produced from the smoke help to preserve the food.
  20. 20. CONCLUSION Food preservation is a process of slowing down food from becoming bad. Besides making the food lasts longer, preservation also prevents food wastage. Food preservation also allows food to be eaten out of season.
  21. 21.  Food preservation gives variety and nutrition to our diet all year round. Freeze-dried food are easy to store and transported because they are light and require less space.
  22. 22. THANK YOU by Wong MC@2011