Changing properties: fats and oils

Changing Properties: Fats and Oils

  • Fats and oils undergo several changes when exposed to heat and through their interaction with other ingredients, leading to the creation of new flavours and textures.

Melting Point

  • Fats and oils have different melting points, which play a significant role in food preparation.
  • This is important in techniques like creaming, where solid fat is beaten with sugar to produce a light texture in baked goods.

Smoke Point

  • The smoke point is the temperature at which an oil starts to smoke and break down, producing harmful compounds.
  • Different oils have different smoke points. For example, extra virgin olive oil has a lower smoke point and is thus better for low temperature cooking, while canola oil has a high smoke point and is suitable for high temperature cooking.


  • Fats and oils can also be used to emulsify mixtures, meaning they keep water and oil mixed together.
  • This is important in mayonnaise and salad dressings, where oil is slowly mixed into egg yolk, which contains lecithin, a natural emulsifier.


  • Solid fats, such as butter or shortening, create a tender, flaky texture in pastries. This process works because the fat interferes with gluten development in wheat flour, shortening the strands of protein which otherwise create a chewy bread-like texture.


  • Fats can aerate mixtures when vigorously mixed, or creamed, with sugar, trapping air. This is an essential step in making light textured cakes.
  • The creaming method produces a web of fat, sugar, and air that expands when heated during baking to help leaven the product.

Deep frying

  • Deep-frying is a cooking method that relies on fat’s ability to cook food at high temperatures. The food is completely submerged in hot oil, which cooks it quickly and seals in the juices.

Remember that the properties of fats and oils will play a vital role in decision-making when planning a menu or a recipe.