Not all oils are the same as some perform better when heated at high temperatures, whilst others have strong flavours which are ideal for salad dressings. Identifying the nature of the oil is important, as some oils contain much higher levels of detrimental saturated fats. Assessing whether an oil is higher in mono- or poly- unsaturated fats may also help to identify the best cooking oils. Finally, the smoking point of the oil is important to consider as this determines the temperature at which the oil begins to break down.

Extra virgin olive oil and coconut oil are two of the most stable oils which make them great options for deep frying. However, coconut oil comprises 92% saturated fat whereas extra virgin olive oil only contains 14% saturated fat. Therefore, extra virgin olive oil is preferred for deep frying as it has a higher smoking point and does not break down into harmful compounds when heated at high temperatures.  Extra virgin olive oil is made from pure, cold pressed olives whereas regular olive oil includes both cold pressed and processed oils.      

                                                                                                         

Monounsaturated oils are best for shallow frying and baking. Examples of mainly monosaturated fats include avocado, olive and canola oils. In addition, these oils contain lower levels of linoleic acid which means that they don’t break down too soon during frying. Interestingly, avocado oil has one of the highest amounts of monounsaturated fat and it is high in potassium. Olive oil also contains antioxidants including vitamin E which helps to decrease damage to cells.

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Polyunsaturated oils are best used for salad dressings due to their stronger flavours. Mainly polyunsaturated oils include corn, soybean, flaxseed, sunflower and safflower oils. It is important to note that flaxseed oil contains elevated levels of omega-3 fats which can improve risk factors for heart disease and help to fight inflammation. The smoke point (i.e. temperature at which an oil is most stable) for flaxseed oil is 107 degrees Celsius compared to avocado oil which is 270 degrees Celsius, which is why it shouldn’t be used in cooking.

Written by 
Mary-Anne Chamoun
Mary-Anne is an Accredited Practising Dietitian and Accredited Nutritionist who has been working in a clinical setting since 2007. She has a particular interest in managing diabetes, malnutrition, IBS, inflammatory bowel disease, and weight loss.