Cooking oils are simply purified fats

Any supermarket shelf these days will have an enormous range of cooking oils, in fact the selection from safflower and soybean to cold pressed avocado oil can be just too much! Knowing what is best to use for frying, salads and other uses becomes more complex than choosing the best wine for a meal and it is easy to forget the basis – a cooking oil is simply a purified fat.

We hear a lot about the dangers of fat and cutting down on our intake of fat, but generally it is not just the quantity of fat in our diet that is the problem, but more importantly the type of fat. The “bad” fats which can increase the risk of certain diseases are the saturated or trans fats. Some fats, such as monounsaturated and polyunsaturated fats, are thought to actually help to lower the risk of disease.

Oil used for cooking comes in these three main types of fat: saturated, monounsaturated and polyunsaturated. The saturated fats are usually solid at room temperature and come from meat and dairy products but also in oils such as palm and coconut oil. While generally it is accepted that coconut oil is considered high risk and can contain more saturated fat than some animal fat; it must be mentioned that there are reports that indicate it is high in beneficial lauric acid which can help stabilize blood sugar, and some say this could lower the risk of heart disease and diabetes.

Generally, for cooking oils, monounsaturated and polyunsaturated vegetable fats are considered “good”. Polyunsaturated fats, found in oils such as safflower, soybean and sunflower, are liquid at room temperature and oxidize (turning dark) easily. Monounsaturated fats, such as canola, nut and olive oils, are more stable.

The term vegetable oil can refer to a specific oil such as pumpkin seed oil, corn oil or rapeseed oil, or it can refer to a blend of oils, often based on palm, corn and sunflower oils. Being a vegetable oil doesn’t necessarily mean it won’t have any saturated fat in it, depending on the blend.

Oils such as canola, flax seed, peanut, olive, safflower and sunflower do not contain saturated fats and are therefore the choice of many today. However, new oils are coming onto the market all the time and some are being hailed as new super foods.

Rice bran oil for instance is being talked about as one of the world’s healthiest edible oils because it contains vitamins, antioxidants and nutrients and is trans fat free. It is also very light without a strong flavour, making it ideal for cooking and baking. Another oil becoming more popular because of its nutritive properties is argan oil, produced from the kernels of the Moroccan argan tree.

Oils that have been flavoured by immersing aromatic plants, herbs, garlic and so on are growing in popularity but there is a slight health risk in that they can promote the growth of clostridium botulinum (leading to botulism) if not stored carefully.

In the preparation of cooking oils, some oils such as olive, walnut and avocado, can be produced from “cold pressing” where nothing is done but extract the oil and bottle it. Hard oilseeds such as canola or soy usually require some pre-treatment, possible steam treatment, to soften the seeds and extract the oil. However, some oils are extracted with the use of chemicals and also subjected to very high heat which can detract from their nutritional properties.

Oils are essential not only in the cooking process but also in normal diets; they can make or break a recipe; so it makes sense to learn a bit about the different oils now available and take the time to choose carefully and also to experiment.