1 / 11

Food Preservation

Food Preservation. By Simon Chute. What is it?. In the earlier days people would have to go long periods of time without a good supply of food, so they needed a way of keeping food fresh for long periods of time. There are two main reasons for this method of preserving the food:

adeola
Télécharger la présentation

Food Preservation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Food Preservation By Simon Chute

  2. What is it? • In the earlier days people would have to go long periods of time without a good supply of food, so they needed a way of keeping food fresh for long periods of time. • There are two main reasons for this method of preserving the food: • 1. To slow down the bacteria that is causing disease so that they don’t get sick. • 2. To simply kill all of the bacteria so that people don’t die.

  3. Types of Preservation: #1 • Refrigeration and Freezing • This method is very simple. The food is put into a very cold place like a fridge or freezer, which causes the bacteria to grow very slowly which will keep the food fresh for longer rather than the bacteria growing very fast when it is still room temp.

  4. Types of Preservation: #2 • Salting • Salting food is also a very simple method. This method was usually only used for meats because the salt was so expensive. What happens is the meat is literally covered in salt. The bacteria doesn’t like the salt so it wont grow there.

  5. Types of Preservation: #3 • Freeze Drying • Freeze Drying is a bit more complicated. What happens is the food is frozen, then it is attached to a big vacuum which sucks out all of the water in the food. Bacteria likes to grow in water, and if there isn't any water then bacteria will stay away. • Instant Coffee is Freeze Dried:

  6. Types of preservation: #4 • Pickling • Pickling is very Similar to Salting. What happens is the food is placed in a jar of vinegar which is very acidic so the bacteria wont grow because it is too acidic for them.

  7. Types of Preservation: #5 • Alcohol Preservation • This method is also very simple. The food is placed in a jar full of alcohol, and when bacteria tries to grow on the food, the alcohol kills the bacteria. One downside though is that all of your food is going to taste like alcohol.

  8. History Of Preservation • Food Preservation has been going on for almost as long as we can remember. • One of the first methods was to freeze meat on the ice. People in older days who were living in the arctic in cold weather would simply freeze the fish or seal meet on the icebergs. This would keep it fresh for long amounts of time. • Another method for those who were living in warm, tropical places would dry their fruits and meats to keep it fresh. The bacteria wouldn’t grow their because there was no water.

  9. How has it Changed? • Food preservation has changed quite a bit since earlier days. There have been better, faster ways of preserving food like alcohol preservation, and salting. However we do still use some of the old methods like freezing meat, or drying it.

  10. Who invented it? • Nicolas Appert was a chef, and in 1810 he experimented with ways to preserve food. He came up with a method that could preserve soups, vegetables, and more. His method was very simple. He would put the food in big glass jars, put sealing wax on it, and sealed it off with a cork. Then he would cover them in cloth so that it wouldn’t break. Next he put the jars into boiling water and after a certain amount of time, took them out and placed them on shelves and the bacteria couldn’t get to it as long as the jar wasn’t opened.

  11. Picture Bibliography • http://www.whatscookinglehighvalley.com/2011/11/03/preserving-food/ • http://schoolworkhelper.net/food-preservation-history-methods-types/ • http://www.grit.com/Preserving/Preserve-Food-with-Salt.aspx • http://www.21food.com/product/search_keys-nescafe+instant+coffee-p1.html • http://tomatoesonthevine-velva.blogspot.com/2012/05/dirt-to-table-experience-refrigerator.html • http://foodpoisoningsignsinfo.com/tag/preservation-of-food/ • http://www.wired.com/science/discoveries/news/2008/11/dayintech_1117

More Related