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Food preservation

PPT on Food Preservation by Prakhar Aggarwal V A.

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Food preservation

  2. 2. MEANING Food Preservation is the process of treating and handling food to stop or slow down food spoilage, loss of quality, edibility, or nutritional value and thus allow for longer food storage. Preservation usually involves preventing the growth of bacteria, fungi (such as
  3. 3. This means…. that the food treated that way will go bad (spoil from bacteria) later that if it had not been treated that way. For thousands of years, humans have used methods of preserving food, so that they can store food to eat later.
  5. 5.  Food preservation prevents the food from being spoiled by the action of enzymes and microorganisms.  Food preservation increases the safe storage period of foodstuffs.  It increases the availability of out of season foodstuffs.  It increases the availability of various foodstuffs even at distant and not easily approachable places. In other
  6. 6. METHODS OF FOOD PRESERVATION TRADITIONAL METHODS  Drying  Cooling  Freezing  Boiling  Heating  Salting  Sugaring  Smoking  Pickling  Lye  Canning  Jellying  1Jugging  Burial INDUSTRIAL MODERN METHODS  Pasteurization  Vacuum packing  Artificial food additives  Irradiation  Pulsed electric field electroporation  Modified atmosphere  Nonthermal plasma  High-pressure food preservation  Biopreservation  Hurdle technology
  7. 7. Drying (dehydrating) food is one of the oldest and easiest methods of food preservation. Dehydration is the process of removing water or moisture from a food product. Removing moisture
  8. 8. Dehydrated foods are ideal for backpacking, hiking, and camping because they weigh much less than their non-dried counterparts and do not require refrigeration. Drying food is also a way of preserving seasonal foods for later use.
  9. 9. How dehydration preserves foods
  10. 10. Foods can be spoiledby food microorganisms or through enzymatic reactions within the food. Bacteria, yeast, and molds must have a sufficient amount of moisture around themto grow and cause spoilage. Reducing the moisture content of foodprevents the growthof these spoilage-causing microorganisms and slows down enzymatic reactions that take place within food. The combination of these events helps to prevent spoilage in driedfood.
  11. 11. Reasons Why Dehydration is a Great Method of Food Preservation  Does Not Require Electricity.  Is Less Time Consuming.  Makes Winter Meals Easier.  Requires Less Storage Space.  Is Child Friendly.
  12. 12. Pasteurisation is a process that kills bacteria in liquid food. In this method moderately high (62°C to 100°C) temperatures are used (for about 15 to 30 minutes) to inactivate certain enzymes and kill certain other microorganisms specially in milk. Since all pathogens are not killed at these temperatures, pasteurized products need refrigeration after exposure to air. It was invented by French scientist Louis Pasteur during the nineteenth century.
  13. 13. Purpose of Pasteurization • To increase milk safety for the consumer by destroying disease causing microorganisms (pathogens) that may be present in milk. • To increase keeping the quality of milk products by destroying spoilage microorganisms and enzymes that contribute to the reduced quality and shelf life of milk.
  14. 14. Canningis the process of applying heat to food that’s sealed in a jar in order to destroy any microorganisms that can cause food spoilage. Proper canning techniques stop this spoilage by heating the food for a specific period of time and killing these unwanted microorganisms. During the canning process, air is driven from the jar and a vacuum is formed as the jar cools and seals.
  15. 15. Vacuum Packing
  16. 16. Vacuum Packingis a method of packaging that removes air from the package prior to sealing. This method involves (manually or automatically) placing items in a plastic film package, removing air from inside, and sealing the package. Shrink film is sometimes used to have a tight fit to the contents
  17. 17. PURPOSE OF VACUUM PACKING • to remove oxygen from the container to extend the shelf life of foods and, with flexible package forms, to reduce the volume of the contents and package. • It is also commonly used to store dry foods over a long period of time, such as cereals, nuts, cured meats, cheese, smoked fish,coffee, and potato chips • On a more short term basis, vacuum packing can also be used to store fresh foods, such as vegetables, meats, and liquids, because it inhibits bacterial growth.
  19. 19. Sugaringis the process of desiccating a food by first dehydrating it, then packing it with pure sugar. This sugar can be crystalline in the form of table or raw sugar, or it can be a high sugar density liquid such as honey, syrup or molasses.
  20. 20. The purpose of sugaring is to create an environment hostile to microbial life and prevent food spoilage. Sugaring is commonly used to preserve fruits as well as vegetables such as ginger. From time to time sugaring has also been used for non- food preservations.
  21. 21. Saltingis the preservation of food with dry edible salt .It is related to pickling(preparing food with brine, that is, salty water) and is one form of curing. It is one of the oldest methods of preserving food.
  22. 22. Salting is used because most bacteria, fungi and other potentially pathogenic organisms cannot survive in a highly salty environment, due to the hypertonic nature of salt. Any living cell in such an environment will become dehydrated through osmosis and die or become temporarily inactivated.
  23. 23. THANK YOU