These days there are many varieties of culinary oils available and each one is suited to particular cuisines, flavours and cooking temperatures. Here’s a glossary of terms to help you gain a better understanding of them.
The smoke point of oil is the temperature at which it starts to smoke constantly. When this happens, the flavour and chemical composition of the oil shifts and toxic by-products are produced. However, new research indicates that an oil’s smoke point is a poor indicator of its stability and likelihood to break down and form harmful compounds.
Cooking at high temperatures for extended periods can cause oils to oxidise faster and turn rancid. The more an oil can resist reacting with oxygen and breaking down, the greater its oxidative stability. Focus on oxidative stability rather than smoke point when choosing cooking oil. Several factors determine an oil’s stability, including antioxidant content, ratio of fats and how refined it is.
Cooking oils are fats derived from plants, nuts or seeds. All oils have a similar energy content (roughly 650-700kJ per tablespoon), although they differ in the types and ratio of fats they contain, how they’re made and how they react to heat. Not only does this make some oils healthier than others, but also more suitable for certain cooking methods.
These are considered heart-friendly fats, which have been shown to help lower bad (LDL) cholesterol and have abundant disease-fighting antioxidants. Extra virgin olive oil (EVOO) is the richest source of monounsaturated fats and antioxidants, while other sources include peanut, avocado and canola oil.
These fats are essential, as they’re required for normal bodily functions, but you need to get them from food since the body doesn’t produce them. There are two main types of polyunsaturated fats: omega-3 fatty acids and omega-6 fatty acids. Cooking oils such as rice bran, sesame and sunflower oil primarily contain omega-6 polyunsaturated fat, which helps to lower LDL cholesterol. Smaller amounts can also be found in canola and peanut oil.
These are primarily found in animal products and tropical plant oils, such as coconut oil, and these fats tend to be solid at room temperature. However, be careful, as too much saturated fat can increase the risk of heart disease.
All oils are sensitive to light, heat and exposure to oxygen. It’s best to buy them in a dark glass bottle and store in the fridge or a cool, dry place. Oil can be kept for six months once opened. Try buying it in smaller quantities to keep it as fresh as possible.
Words by Kathleen Alleaume