The first thing to consider when picking an oil to cook with level of oxidation that will occur. To explain this a bit more you need to be aware that frying at high temperatures produces free radicals which are quite widely accepted as being harmful to health. Free radicals are thought to be responsible for cell damage and a contributing factor to cancer, heart disease and premature aging as well as depleting vitamin A and E in the body.
All this said the the type of oil, the temperature of you cooking and the length of time that something is fried for will all affect the amount of free radicals produced. When I say type of oil here I am talking about whether an oil is saturated, monounsaturated or polyunsaturated and I have given a bit more detail on each below:
1. Saturated Fats - these are usually solid at room temperature and ironically are thought to be the healthiest type of oil to cook in. Usually these are animal fats but the plant based options are coconut oil and palm oil.
2. Monounsaturated Fats - these are usually liquid at room temperature but start to become solid if chilled. They are thought to be almost as good for cooking in as saturated fats.
3. Polyunsaturated Fats - these liquid fats that are thought to have the greatest health benefits are thought to be the worst to cook in as the produce free radicals at lower temperatures.
In terms of cooking methods, the longer you cook for and the more oil you use the worse the situation will be. So deep frying food is thought to have negative effects for your health, whatever oil you choose. When frying food you are best to use a technique of brazing. To do this all you need to do is heat a small amount of oil in a pan and fry your food for a minute or two and then add about 1cm or 1/2in of either water or stock and put a lid on the pan and let it cook in its own juices. This will create and surprisingly tasty flavor and be a lot less damaging to your health.
Ok so we have done a quick overview of oils and of ways that you can use them and so we will now look at each of the oils individually.
Coconut Oil
Coconut oil is probably the best fat for frying for a number of reasons. The first one being that it is a saturated fat and as already discussed these are the best types of oils for frying. Also of all the saturated fats coconut oil is the most healthy this is because it is a short-chain saturated fat whereas animal fats are long-chain saturated fats and although diets high in animal fat have been shown to be linked to heart disease the same cannot be said for coconut oil. You can get coconut oil in a virgin raw form which means it comes as is and does have a flavor of coconuts. You can also get it slightly steamed which is odourless and make the perfect vegan alternative to butter.
Olive Oil
Olive oil is a monounsaturated fat and thought to be the most stable of all the monounsaturated fats as a result is the best one to cook with. Having said that you get different grades of olive oil and some are better for cooking with than others. If you want to use olive oil for cooking then go for a medium or mild olive oil. The more expensive and flavoursome extra virgin olive oil should be saved for salad dressings and drizzling after cooking.
Sunflower Oil
This is a commonly available oil and was once recommended as a healthy cooking oil as it is a polyunsaturated oil. However with the knowledge now that this type of oil oxidises and produces free radicals a lot more easily then I would avoid cooking with sunflower oil. It is best used in salad dressings and good for things like soaking sun dried tomatoes.
Rapeseed Oil
Also known as Canola Oil this is probably the most common oil in the market today. It is a monounsaturated fat but has a much lower smoking point than olive oil and so is not so good for frying. However this oil might be a good one for using in baked goods as it is a low cost option and better for low temperature cooking.
Sesame Seed Oil
This is one of my favorite oils for flavor but not for cooking. Sesame seed oil is a polyunsaturated oil and so not suited to cooking, not to mention the fact that cooking takes the flavor away as well. This oil is perfect for dressings and also for adding to cooked noodles in oriental dishes.
Palm Oil
Palm oil is actually a saturated fat and so falls into the category of oils that are good to cook with. However before choosing palm oil as your cooking oil of choice you need to consider the impact on the environment which is great where this oil is concerned. If you do want to use palm oil then it is probably best to use a sustainable source.
Peanut Oil
You might often see this labeled as groundnut oil and it is a monounsaturated fat that is not quite as good for cooking as olive oil but is not bad. It has quite a mild flavor but can also be used in salad dressings as well as for lower temperature cooking.
Avocado Oil
Avocado oil is actually a monounsaturated oil that has a very high smoking point and so would be a good option for cooking. One of the disadvantages to using this oil is it might be difficult to get hold of and more expensive than other oils. It would also be a wonderful oil to use in salad dressings and might be best saved for that.
Nut Oils
Most nut oils are monounsaturated fats however they generally have low smoking points which make them a lot less stable than olive oil and so not great for cooking. They would be excellent for salad dressings as they will add some excellent flavor but you might also want to use them for low temperature cooking like baking granola. Oils included in this section are:- Almond Oil
- Hazelnut Oil
- Macadamia Nut Oil
- Walnut Oil
Seed Oils
I have looked at a few seed oils already and they are all similar in that they are generally polyunsaturated oils and do not lend themselves to cooking. Seed oils are full of your omegas and these are destroyed at high temperatures and so these oils are wasted. These are perfect for adding to salads or to drizzle over any meal. The oils included are:- Flaxseed Oil
- Grapeseed Oil
- Pumpkin Seed Oil
- Safflower Oil
