Food processing

• Reason for food processing

  • Preservation: Extends the shelf life of food by inhibiting the growth of microorganisms, enzymes,
  • Safety: Ensures food is safe to eat by removing harmful bacteria.
  • Convenience: Enhances the ease of preparation and consumption, making food products more accessible and easier to use.
  • Nutritional Enhancement: Enriches the nutritional content of food through fortification or enrichment, adding vitamins and minerals.
  • Sensory Modification: Improves or alters the taste, texture, colour, or aroma of food.
  • Economic: Reduces food waste
• Primary processing 


  Cleaning- removes dirt

  sorting- spearing food based on side etc

  grading- categorising food

  milling- grinding grains into flour

  slaughtering- processing meat from animals

  pasteurisation- heating liquids to destroy organisms
• Examples of primary processing

  • Milling Wheat into Flour: Transforming raw wheat grains into

  • Pasteurizing Milk: Heating milk to eliminate bacteria and

  extend its shelf life.

  • Freezing Vegetables: Preserving vegetables by freezing

  them shortly after harvest.
• Secondary processing

  • Mixing: Combining different ingredients
  • Forming: Shaping food into specific forms.
  • Cooking: Applying heat to prepare food for consumption.
  • Baking: Using dry heat in an oven to cook food.
  • Fermenting: Using microorganisms to convert sugars into alcohol or acids.
  • Canning: Sealing food in airtight containers and heat processing to preserve it.
• Reasons for processing convenience foods

  • Time-Saving: Designed for quick and easy preparation.
  • Longer Shelf Life: Processed to extend the food's lifespan.
  • Variety and Accessibility: Provide a diverse range of food options that might not be readily available in fresh form in all locations or seasons.
  • Portion Control: Often packaged in individual servings.
  • Nutritional Enhancement: Some convenience foods are fortified with vitamins and minerals to enhance their nutritional value.
• Classification of convenience foods

  Ready-to-Eat Food- Foods that can be consumed immediately without further cooking or preparation.

  ready to cook food- Foods that are pre-prepared and require cooking but minimal additional preparation.Ready-to-Heat Foods- Pre-cooked meals or components that simply need to be heated before eating.Meal Kits- Contain all the necessary ingredients in exact amounts required to prepare a dish. Snack Foods- Small, quick, and convenient food items
• Advantages of convenience foods

  • Time and energy saving
  • Consistent quality
  • Year-round availability
  • Variety
• Disadvantages of convenience food

  • Nutritional quality eg high salt, sugar and fats
  • Cost
  • Environmental impact - packaging contributes to waste
  • Taste and freshness
  • Health concerns
• Cook-chill food production 


  Made by secondary processing. Involves food being prepared, cooked and portioned Then chilled to 3°c and packaged for sale. Eg pasta, salads, chilled desserts
• Cook pasteurise chill food production - fresh veg soup

  1. Prepared: vegetables are washed and chopped, and stock is made.
  2. cooked: veg are cooked under controlled conditions until core temp reaches minimum of 72°, Thickening agents, e.g. cornflour or cream, are added, veg is blended to form a smooth mixture.
  3. Portioned and packaged: into retail sized portions
  4. Pasteurised: past. At 80° for 10 min
  5. chilled: rapidly chilled by blast chilling at 3°C.
  6. Quality control: soup is tasted and tested for quality using sensory analysis.
• Cook pasteurise chill food production: fresh veg soup

  7. labelled: type, ingredients, storage, allergy and nutritional info

  8. Stored: 1°-3°C

  9. Distributed: transported in cold conditions and then stored in chilled cabinets in shops
• Functional food 


  Contain added ingredients that gives food health benefits over their basic nutritional value.
• Examples of functional foods

  • probiotics (good bacteria eg lactobacillus): bio yoghurts: improve function of digestive system eg reduce bloating, strengthen immune system
  • omega 3 fatty acids (oily fish): omega 3 eggs: lower levels of cholesterol, aid brain function
  • Plant stanols and sterols (plant extract): dairy spreads, milk: lower cholesterol
  • Folic acid (B9): breakfast cereal: reduce incidence of neural tube defects
• Generally modified foods (GM) 


  Foods produced from plants that have had changes introduced into their dna. Foreign genes are inserted into genetic codes of plants. This can create plants that are disease resistant, req fewer pesticide, grow faster
• Primary processing 


  Involves changing or converting raw Food material into a food that lasts longer, fit for sale ans is ready to eat or cook
• secondary processing 


  Involves Changing or converting primary processed foods into other products. This produces added value foods