Cooking oils are a seasoned cook’s best weapon. With a booming food industry and a modern population that has become more conscious and informed about their health, talking about cooking oil has become important. Foods that have been prepared with cooking oil are part and parcel of every culture, in every part of the world. As one of the essential nutritional elements, next to proteins and sugars, a diet that consists of cooking oils is a must. There are many varieties of cooking oil, each with their own special characteristics and uses.
All about Cooking Oils
What are oils?
Oils refer to viscous liquids that are generally derived from seeds of plants, nuts or fruits. Oil is acquired from fruits, seeds and nuts through solvent distraction, which usually involves adding substances that dissolve the oil from the source. Oil is also acquired through grinding and pressing mechanisms that extract it in a more natural manner.
All oils are made up of unsaturated fatty acids. Oils exist as liquids in room temperature because they are made up mostly of unsaturated fatty acids, and it is these unsaturated fatty acids that make oils healthy and capable of lowering the levels of cholesterol in the blood.
Before you can use oil, understanding the type of oil that you are cooking with can help you determine whether it is the right type of oil to use and whether it will be healthy for you. Examples of unsaturated oils include olive oil, Rapeseed oil, soybean oil, palm oil, sunflower oil, corn oil, and so on.
What are fats?
Unlike oils that are made up of unsaturated fatty acids, fats are comprised of saturated fatty acids. Saturated acids typically exist in solid form and are only capable of melting when they are exposed to high temperatures. Unsaturated fats are known for hardening within the body which can cause health problems when consumed in excess.
Unsaturated fats can further be broken down to trans-unsaturated, monounsaturated, and polyunsaturated fats. Polyunsaturated and monosaturated fats are the only types of fats that exist in liquid form. Monosaturated fats are stable to oxidation, which is why it takes them longer to become rancid.
Polyunsaturated fats, alternatively, are generally less stable to oxidation and are perfect for use if you live in cold temperature areas. Examples of fats include butter, lard or pork fat, tallow or beef fat,
Similarities and differences between fats and oils
Fats and oils each have their own characteristics and can be utilized when cooking food over high temperatures. But certain fats and oils are better suited for use over little to no heat. As such, before you can use any oil, it is vital that you understand its best uses, as well as its smoking points. Both fats and oils are similar in that:
- They are both made of the components carbon (C), hydrogen (H), and oxygen (O)
- Both fats and oils are needed for a healthy immune system
- They are both made of long chain fatty acids
The differences between fats and oils include:
- Oils come highly recommended by dietitians and health enthusiasts because they decrease the risk of cardiovascular diseases while fats can increase it.
- At room temperature, fats are solid while oils maintain a liquid state
- Fats typically originate from animal sources while oils are acquired mainly from plants
- Oils have low oxidative rancidity while fats have high levels
- Oils are stored in the fruits and seeds of plants while fats are usually found beneath the skin of animals and in the liver. The specialized cells that store oils are known as fat granules while those of fats are referred to as adipocytes
How are oils produced?
People in many different parts of the world have been producing cooking oil for years from peanuts, olives and safflowers and an array of many different plants. In the beginning, oil would be produced by overheating an oily plant product until oil was extracted. Today, the extraction methods have become a little more sophisticated which has allowed the production of cooking oil to be more efficient.
The manufacturing process of cooking oils varies. Some oils such as peanut and coconut are typically extracted by cold pressing. Cold pressing produces a light and flavourful oil without any processing having to be done. Most oil cooking oil sources, however, are generally considered unsuitable for cold pressing since it would leave a lot of contaminated elements or it would result in a bitter product. Therefore, a large majority of cooking oils available are habitually put through different stages of processing to produce the consistency that you enjoy today.
Based on the different types of manufacturing processes, cooking oils can either be categorized as:
- Refined cooking oil
- Unrefined cooking oil
Refined cooking oil
Most of the cooking oils available today are refined cooking oils. During the process of refining, the oil is put through a solvent extraction process before it is bleached and finally deodorized. As the oil goes through each of the stages, the original flavour, colour and order of the oil become reduced.
Although this process causes the oil to lose its most important properties, the refining process also makes the oil more stable, which means that it does not oxidize as easily as unrefined oil. Unlike unrefined oils, refined oils can withstand exposure to light, air and heat for long durations without going rancid.
When buying refined oil, you should only limit yourself to refined oils that have been manufactured by a company whose refining process does not utilize harmful chemicals. Refined oils are great for cooking at medium to high temperatures. Some examples of refined oils include canola oil, safflower oil, refined peanut oil, and refined sesame oil.
Unrefined cooking oil
Unrefined cooking oils also go by virgin or extra virgin oils. Rather than use chemical extraction methods that are often featured in refined oils, unrefined oils are created using a mechanical process. During the extraction process, excess pressure is applied to extract the oil from the resulting pulp.
Because nothing is added or removed, unrefined oils tend to maintain their original flavours and colours of the seeds, plants or nuts that they were extracted from. It is because of this that unrefined oils are recommended for use; not only are they rich in nutrient content and full-bodied flavour, but they are also said to be the healthiest and the best for human consumption.
While unrefined oils are known to be healthier, their quality does not last long as they usually deteriorate over time as a result of exposure to the elements. When unrefined oils are left to sit for too long, they are likely to develop a rancid smell and taste as a result of oxidation.
Unrefined oils last a lot longer when stored in a dark area to preserve them for as long as possible. Examples of unrefined oils include canola oil, high oleic safflower oil, hazelnut, peanut oil, wheat germ and refined sesame oil, and many more.
How to pick the right cooking oil
When thinking about the best cooking oils to use, there are certain things that you have to keep in mind. Anyone can pour cooking oil and start cooking. However, picking the right oil can make all the difference in the world as it can mean the difference between a bland meal and a well-cooked one.
Depending on the cooking method that you settle on, whether deep frying, roasting or grilling, the type of cooking oil that you select will produce different results. When picking a cooking oil here are some things that you have to pay attention to:
- The cooking oil’s stability/ oxidation
- Its smoke point
- The quality of the raw ingredients used during the manufacturing process
The cooking oil’s stability
The best cooking oils are the ones capable of remaining stable even when exposed to high temperatures. Good cooking oils should also have oxidative stability. This simply means that the oil should be able to resist oxidation, which is the process that forms free radicals from fat molecules in the oil. Free radicals are bad for your health- they cause a host of issues including heart disease, cancer, inflammatory diseases like arthritis, and excessive ageing. As such, it is extremely vital to select an oil that has high oxidative stability.
An oil’s oxidative ability is dependent on its chemical composition, the smoke point and the amount of antioxidant matter contained in the oil to prevent oxidation from occurring. The degree of saturation of the fatty acids in the oil can also determine the oil’s resistance to oxidation.
For instance, tropical oils like palm and coconut oil, as well as animal fats like butter and ghee, are full of saturated fatty acids. It is these saturated fatty acids that provide the stability needed to resist oxidation. These types of oils should be used for deep frying or cooking anything that is to be subjected to high temperatures.
Cooking oils that contain monosaturated fatty acids are not as densely packed as saturated fatty acids, which means that they cannot be exposed to as much heat. Examples of cooking oils that contain monosaturated fatty acids include olive oils, oils made from nuts, as well as avocado oil.
Cooking oils that contain polyunsaturated fatty acids tend to be very unstable and therefore produce large amounts of radicals whenever they are heated. As a rule of thumb, you should try to stay away from cooking oils that contain polyunsaturated fatty acids such as soy oil, rapeseed oil, safflower oil, and cottonseed oil.
The cooking oil’s smoking point
Before you can pick a cooking oil, it is important to understand what its smoke point is. Put plainly, the smoke point refers to the temperature at which oil starts to burn and smoke. The more stable an oil is, the higher its smoke point. When oil reaches its smoke point, it starts to break down and can be incredibly damaging to your health like free radicals and toxic fumes.
As oils reach their smoke point, they also begin to form dangerous compounds such as acrolein, which is one of the components that is known to cause ulcers and gut problems. When oil reaches its smoke point, it also means that it has lost most of its beneficial nutrients. When oil starts to smoke, it may reach its flashpoint, which is the point at which it may catch fire.
Smoke point and stability of the cooking oil go hand in hand. Because polyunsaturated fats are the most unstable, manufacturers usually rely on industrial level refinement processes to make the polyunsaturated fats stable enough to withstand high temperatures. Most polyunsaturated cooking oils are usually unrefined and because they do not play well with heat, they are only used for dressings, drizzling and low-temperature cooking.
The best cooking oils to use for high-temperature cooking are therefore refined oils. Refined oils typically have a neutral flavour, they enjoy a longer shelf life, as well as a high smoke point.
The quality of raw ingredients used
The quality of the ingredients used is vital for de3termining the quality of the cooking oil that you are going to pick. Organic oils produced from seeds, grains, and nuts are ranked higher in quality compared to the non-organic ones. Obviously, if you want to stay healthy, organic oils come highly recommended over non-organic counterparts.
Common types of cooking oils used today and the best oils for day to day cooking
- Olive oil
Olive oil is made by crushing olives to create a paste; olive oil is then extracted from the paste. Olive oil is available in different textures, colours and flavours; some are green and produce grassy flavours while others are golden and smoky. Olive oil has one of the lowest smoke points out there so you should not use it for high-temperature cooking. Instead, it should be drizzled over salads, bread, veggies or anything to be eaten raw.
- Coconut oil
Coconut oil is one of the few oils out there that remains solid even at room temperature, which means that it sometimes cannot be used for dressings or vinaigrettes like olive oil can. Coconut has become increasingly popular in recent times because of the host of health benefits that it offers. Because of its consistency, it is often used for baking and can also be used in place of other vegetable oils. Coconut oil is also great for stir fry.
- Canola oil
Canola oil is a neutral oil which means that it can be used in a range of situations and cooking styles including roasting, frying and searing.
- Avocado oil
Avocado oil not only has numerous benefits to offer, but it is one of the best cooking oils to use for high heat situations because it has a smoke point of 520ºF compared to canola oil’s 400º.
The worst oils to cook with
- Soy, peanut and corn
These oils should be consumed minimally as they contain high amounts of unstable polyunsaturated fats which can lead to diseased. Because of the high amounts of polyunsaturated components, it also means that the oils are unstable and prone to oxidation.
- Safflower Oil
Safflower oils also contain high amounts of polyunsaturated fats, which gives the oil its low smoke point. It also means that it is capable of forming radicals a lot faster than most other oils.
- Walnut oil
Walnut oil has a high concentration of monosaturated fats, which actually makes it one of the healthiest options out there. But it also has a low smoke point, which means that it is best enjoyed over salads like olive oil.
How to get the most of your cooking oils
An oil that has a high smoke point is prone to oxidation, which means that it becomes faster whereas an oil that is resistant to oxidation may very likely have a low smoke point. As such, there is no clear winner as to which cooking oil you should have in your house. The best way to make the most out of your cooking oil is to have as much variety as you can stock up, which will allow you to always be prepared for every culinary occasion possible.
How to store your cooking oils
To keep your oils as fresh as possible, it is essential that you store them properly. If you do not, your oils can start to go rancid, which will cause your recipes to taste awful in return. Cooking oils can also go bad after they have been left in storage for a long time. The cooking oil might not show signs of mould, but when they turn rancid, they should not be used.
Before you cook using any oil, it is generally a good idea to give it a good sniff. Most cooking oils have a neutral smell or one that is very light. If yours has started to smell, you should dispose of it immediately.
In general, most cooking oils can be stored safely in a pantry, especially if you use them on a regular basis. However, you should strive to store your oils in a cool, dry area away from direct sunlight to prevent them from turning faster than they should. Cabinets make great storage spaces but there are some oils such as corn, sesame and sunflower oils that can be stored in the refrigerator.