Food preservation

• Food preservation


  The process of preventing food spoilage by creating conditions under which microorganisms cannot multiply and grow
• Preserved food products are delicious and in demand. Some are considered delicacies that people crave for.
• Different ways of preserving food

  • Drying
  • Freezing
  • Salting
• Drying


  • Removal of moisture or water in food
  • Oldest method of food preservation, going as far back as the ancient Egyptians
  • Can be natural (drying under the sun) or artificial (drying using an equipment)
  • Food preserved through drying should be turned once in a while for uniformity and equal dryness
• Natural drying


  Food is placed on flat containers and left under the sun to dry
• Artificial drying


  1. Food is put inside an equipment (oven) that uses artificial heated air with controlled temperature, humidity, and airflow

  2. The maximum drying temperature is around 50 to 62 °C

  3. High temperature may be used during initial drying to remove moisture as quickly as possible
• Freezing


  • Turns food into solid state at very low temperature
  • Completely different from refrigeration
  • Freezers have much lower temperatures
  • Fruits and vegetables may be placed in a freezer to maintain their freshness and nutrients
  • Frozen food should only be taken out before use, otherwise it will lose its nutrients and flavor
• Freezing process


  1. Choose fresh, ripe, and bruise/spot-free fruits or vegetables

  2. Wash the food thoroughly

  3. Peel and cut the food

  4. Add syrup (1 cup sugar and 1/2 cup water) or dry sugar to the food

  5. Ascorbic acid (1 tablet) can be also added to maintain its flavor

  6. Mix the food with the syrup, then pack it in a container

  7. Place it in the freezer
• Salting


  • Uses salt, which can be rock salt or iodized salt, as its main preservative
  • Preserves food by osmosis - the water in food is removed when it is salted
  • Reduces or totally prevents food contamination
  • Commonly done to poultry (eggs), fish, and seafood
  • One of the most common and easiest method of food preservation
  • Other salted preserved foods are mixed with sugar, spices, and other flavorings
• Dry salting


  Putting salt in layers in a jar, pot, or tray to draw out the water content of the food
• Wet salting or brine salting


  1. Adding salt to boiling water, then mixing it until it dissolves

  2. Food is immersed in the brine solution when it has cooled
• Salted vegetables and fruits


  • Santol
  • Green mangoes
  • Cucumber
  • Onions
• Salted poultry and fish products


  • Itlog na pula
  • Tuyo
  • Daing
• Benefits of food preservation


  • Prevents spoilage of food
  • Retains the nutrients and texture of food
  • Maintains the good and sanitary quality of food
  • Makes seasonal food such as fruits available all year round
  • Provides a means of income or livelihood for the family and the community
• Tools and utensils used in food preservation


  • Mixing tools (wooden spoon, tongs, ladle, turner)
  • Cutting tools (kitchen scissors and shears, paring knife, chopping knife, peeler)
  • Measuring tools (measuring cups and spoons)
  • Weighing scale
  • Colander and strainer
  • Pots and pans
  • Pressure canner
  • Salometer
  • Food processor and blender
  • Containers (plastic, ceramic, glass)
• The law of Conservation of energy states that energy can neither be created nor destroyed; it can only be transformed.