food processing and packaging

• Food processing

  Treating foods to make them easier to use
• Food preservation


  A form of food processing that slows down food spoilage, which is caused by enzymes, moulds, yeast or bacteria attacking food
• Freezing


  Bringing food quickly to a temperature of -18°C or below. Enzymes and microorganisms are not killed at this temperature, but they become inactive. Once food is thawed, enzymes and microorganisms become active again.
• How freezing works


  1. Fresh food needs to be frozen as quickly as possible so that small ice crystals are formed. This means that food does not lose its shape and nutrients upon thawing.

  2. If food is frozen slowly, large ice crystals form, and the food loses nutrients and becomes mushy when thawed.
• Guidelines for home freezing

  • Organise your freezer well
  • Turn the freezer to its coldest setting two to three hours before freezing, cool foods before freezing and do not freeze too much at a time
  • Blanch vegetables before freezing
  • Choose suitable packaging, e.g. plastic freezer bags. Care should be taken to seal containers well, or freezer burn will result and food will be inedible
  • Freeze in useable amounts (e.g. enough vegetables for one meal) so that only the amount you need will be thawed
  • Label foods clearly with the name of the product and the date it was frozen
  • Foods that are likely to stick together (e.g. berries or peas) should be open frozen before being packed into bags
• Blanching


  Destroys enzymes that can reduce the quality of frozen vegetables
• Open freezing


  Foods that are likely to stick together, e.g. berries or peas, are frozen without wrapping before being packed into bags
• Blast freezing


  A commercial method of freezing where very cold air (-35°C) is blown over food to freeze it quickly
• Freezer burn occurs when frozen food becomes dried out or has been exposed to air in the freezer
• Information on frozen food packaging

  • Name of product
  • Date frozen
  • Ingredients
  • Nutritional information
• Vegetables with a high water content, such as cucumber or lettuce, are not suitable for freezing as they go limp
• Whole eggs are not suitable for freezing as they crack (although egg white and yolk can be frozen separately)
• Milk, cream and mayonnaise are not suitable for freezing as fat and water separate
• Reasons food needs to be packaged

  • Protect food from contamination while it is being transported and stored
  • Make food easier to transport and store, both before and after sale
  • Help preserve food, e.g. tinned peas
  • Provide information, such as nutritional information, storage and cooking instructions
• Characteristics of good food packaging

  • Strong
  • Easy to open
  • Resealable if necessary
  • Hygienic
  • Non-toxic
  • Biodegradable or recyclable
• Biodegradable packaging


  Made from plant-based materials that can be easily decomposed (broken down) by microorganisms. Therefore, it does not pollute the environment. Examples include paper and cardboard.
• Recyclable packaging


  Packaging that can either be reused as it is (e.g. glass bottles) or processed so that it can be reused (e.g. cans are crushed, melted, rolled flat and used to make new cans). Glass, metal, card and paper can be recycled. Packaging that can be recycled carries the recycling symbol.
• Disadvantages of food packaging

  • Some packaging, such as soft plastic, is not biodegradable or recyclable and litters and pollutes the environment.
  • Packaging such as paper and cardboard uses up natural resources (i.e. trees), which is harmful to the environment.
  • Packaging adds to the price of a product.
  • Packaging can deceive the consumer, e.g. the quantity inside the package can be much smaller than expected.
• Sustainable consumer


  One who makes an effort to minimise their impact on the environment.
• Steps to be a sustainable consumer

  1. Avoid buying products that use excessive packaging.

  2. Examine food packaging and choose products in biodegradable or recyclable packaging.

  3. Always bring reusable shopping bags when shopping.

  4. Reduce the amount of packaging you use, e.g. buy loose fruit and vegetables.

  5. Reuse packaging for other purposes, e.g. plastic takeaway cartons for freezing food.

  6. Recycle packaging, using your local bottle bank and household green bin.
• Information that must be displayed on food packaging

  • Name of food
  • List of ingredients: main ingredient (by weight) listed first
  • Quantity (%) of certain ingredients, e.g. beef in beef burgers
  • Allergen information (if any), e.g. contains nuts
  • Net quantity
  • Use-by, best-before or sell-by date
  • Storage instructions
  • Name and address of manufacturer
  • Instructions for use (if necessary)
  • Nutritional and dietary information (if product is making health claims, e.g. low fat)