Edible Cooking Oil is one of the most essenital items in every kitchen, drops of oil are the first ingreident in the cooking process , Nutrishilp brings this blog to develop an insightful understanding of this daily need product. lets begin with the very basic question.

Why do we use cooking oil?

For heat transmission. If you Just place food on a very hot surface, it will get scorched where it is in contact, and remain raw where it is not. Fat (oil, butter, lard, etc.) are excellent at transmitting heat from the pan to the food. Thus the food will cook evenly and not burn.

Oil increases the surface area of your cooking surface. Better distribution of heat would seem to allow for faster overall cooking of the food. So it becomes important to choose cooking oil which will ensure a healthy lifestyle. As a result, it is necessary to make a conscious choice while purchasing cooking oil.

One should keep in mind while making a rational choice upon considering the following factors about the cooking oil –

A. Oil composition.
B. Smoke point of oil
C. Extraction process.
D. Quality of Raw Ingredients

A. Oil Composition –

Since cooking oils are made up of saturated (SAFA), polyunsaturated (PUFA) and monounsaturated (MUFA) fatty acids. It is important to create a balance. Saturated fats are highly stable that resists oxidation and aids digestion. However, they are less healthy than the polyunsaturated and monounsaturated fats.

Both polyunsaturated and monounsaturated helps in preventing diseases like high cholesterol and heart attack. So a balance needs to be created between these acids.

Stability depends on how easily the cooking oils oxidize; that is, how easily they react with oxygen to form free radicals. The most important factor in determining oil’s resistance to oxidation is the relative degree of saturation of the fatty acids in it. Let’s understand these composition elements ,one by one –

Saturated Fatty Acids (SFAs)

Saturated fatty acids have their carbon chain completely filled (saturated) with hydrogen atoms. This saturation yields a highly stable structure that resists oxidation. Saturated fatty acids are found in tropical oils – such as palm oil and coconut oil – and animal fats – such as butter or ghee. These oils and fats are the most suitable for deep-frying and cooking under high temperatures.

Monounsaturated Fatty Acids (MUFAs)

Monounsaturated fatty acids miss two hydrogen atoms and have one double bond between their two carbons instead. Since monounsaturated fatty acids aren’t densely packed, they can’t be exposed to such high heat as saturated fatty acids. Monounsaturated fatty acids can be found in olive oil, avocado oil, and nut oils.

Polyunsaturated Fatty Acids (PUFAs)

Polyunsaturated fatty acids miss several hydrogen atoms and have two or more double bonds. Try to stay away from oils with lots of polyunsaturated fats, such as canola (rapeseed) oil, corn oil, cottonseed oil, grapeseed oil, rice bran oil, safflower oil, sunflower oil, and soy oil. These are very unstable and produce high levels of free radicals when heated.

One of the most important things to consider when consuming PUFAs is their ratio of omega-6 to omega-3.

This is a recipe for disaster because omega-6s are pro-inflammatory, while omega-3s are anti-inflammatory, as inflammation contributes to various diseases, including cardiovascular disease, arthritis, liver disease, depression, and even cancer. The ideal situation is less total PUFA with lower ratio of omega-6 to omega-3.

The next vital point to consider is –

B. Smoke Point of Cooking Oils

The smoke point is literally the temperature at which the oil stops simmering and starts smoking. The more stable the oil, the higher its smoke point is. When oil is heated past its smoke point, it decomposes – it loses its beneficial nutrients, generates toxic fumes, and creates harmful free radicals. Also, when there’s smoke, it means the oil is very close to its “flash point” – the point at which it may catch on fire.

Thus, smoke point and stability go hand in hand.

For deep-frying, it is recommended to use refined oils safflower oil and rice bran oil, as they are perfect for your heart and can withstand frying temperatures of almost 500° F. You can also use peanut oil, sunflower oil, mustard oil or vegetable oil if you’re frying at 400-450° F.

Even ghee too has high smoke point but it proves to be really costly affair for the purpose. Pan-frying requires less oil and lower temperatures too. It is recommended to keep it ideal for fats with smoke points at 350° F or lower. For pan-frying cold pressed oil as avocado, canola or olive oil can be considered.

Refined oils normally have high smoke point as they undergo heat treatment .Thus for deep frying or high temperature cooking, use refined oil. But for shallow frying, salad dressing, the oil with low smoke points such as cold pressed ones can be used. It is advised to choose the oil as per your usage; Ghee too, has high smoke point which makes it an apt choice for deep frying although cost constraint can make you think of other choices.

C. Extraction process

On this basis there are two different types of oils: unrefined and refined.

Unrefined Oils

Unrefined cooking oils occur exactly as they do in their plant form. They are mechanically extracted from their oily parts through crushing and pressing and then left in their virgin state. This extraction process preserves their high flavor and nutrients, making them a healthier choice.

If the extraction occurs in uncontrolled temperature conditions (along with heat born from friction created during the pressing), the oil is expeller-pressed. If the temperature is made steady below 80-90°F (26-32°C), the oil is cold-pressed – that is, expeller-pressed in cooler temperatures. Cold-pressing retains the most aroma, color, flavor, and nutrients.

They tend to have a low smoke point and are most suitable for drizzling, dressings, and lower temperature cooking. But have short shelf-life.

There can also be Filtered oils or Kachi ghani as we call in India are the ones which are filtered through strainers to eliminate the solid particles & other impurities from the seed .They appear to be more dark and cloudy and also the smell is more prominent. You might have come across filtered coconut, ground nut, mustard oil, which are costly but worth.

Refined Oils

Refined cooking oils are made by highly intensive mechanical and chemical processes. Modern extraction consists of several steps:

1. Crushing the seeds and heating them in a steam bath.
2. Putting the seeds through a high volume press which uses high heat and friction to press the oil form the seed pulp.
3. Bathing the seeds in a hexane solvent bath and then steaming them again to squeeze out more oil. (Note: hexane is produced by the refining of crude petroleum oil).
4. Putting the seed/oil mixture through a centrifuge and adding phosphate to begin the separation of the oil and seed residues.
5. Refining the crude vegetable oil, including degumming, neutralizing, and bleaching.
6. Deodorizing the final product.

This exercise makes it easier to sell for the manufacturer as the oil has longer shelf life, higher smoke point and also the oil has a neutral flavour.

If you need oil for a higher-heat cooking or oil that doesn’t have a strong flavor, look for naturally refined cooking oils, using lower temperature and natural agents like citric acid. Refined coconut oil is one of the best.

There is a not so healthy variant of refined oil –

Hydrogenated Oil

Many refined oils also undergo a process known as hydrogenation. Hydrogenation involves adding hydrogen into omega-6 polyunsaturated oils to prevent them from going rancid and to make them solid at a room temperature, primarily as a cheaper and less perishable alternative to butter in the form of margarine and shortening.

Hydrogenation produces trans fatty acids (trans fats), which are particularly dangerous to human health. These artificially saturated fats are difficult for the body to metabolize and remain “stuck” in blood circulation, contributing to an increased risk of cardiovascular disease and cancer.

Some of the most commonly hydrogenated oils include corn, cottonseed, safflower, and soy. But theoretically, almost any polyunsaturated oil can be hydrogenated.

There is one last but not the least factor –

D. Quality of Raw Ingredients

The quality of the original raw ingredients (nuts, seeds, grains, legumes, fruit) is crucial in determining the eventual quality of the fat. Organic oils are much better than their non-organic counterparts. The reason is that pesticides are fat-soluble and accumulate in plant’s fatty acids. And since oils are very concentrated, pesticides and other environmental toxins pack more punch in a small amount.

The charm of Olive Oil –

There is one premium cooking oil which often attracts the consumers differently its array of choices, lets discuss it separetly for better clarity –

Extra-Virgin, Virgin, Pure, or Light

Extra-virgin olive oil is an unrefined olive oil and the highest quality oil you can buy. There are very specific standards olive oil has to meet in order to deserve the label “extra-virgin”. It contains no more than 1% of oleic acid and typically has a golden-green color and a true olive taste.

Virgin olive oil is also unrefined and comes after extra-virgin olive oil in terms of quality. Virgin olive oil has a slightly higher level of oleic acid, lighter color, and less intense flavor.

Pure (regular) olive oil is usually a blend of virgin olive oil and refined olive oil. It’s a lower-quality oil with oleic acid between 3-4%, lighter color, and mild flavor.

Light olive oil is a refined lowest quality olive oil. The term “light” doesn’t refer to calories, but to a lighter (neutral) flavor. Out of all the types of olive oil, light olive oil has the highest smoke point.

Key points to remember –

• The worst type of dietary fat is trans fat. Avoid it whenever possible.

• Monounsaturated fats are among the most healthful fats. Recent studies have also found virgin coconut oil to have many positive health benefits. While coconut oil is made of 90% saturated fat, half of it is lauric acid, which has a number of health-promoting properties.

• Unrefined oils are superior to refined oils. Naturally refined oils are better than industrially refined oils.

• Organic oils are rank higher in quality than their non-organic counterparts.

• For Indian cooking style filtered variety of nuts based oils as coconut , groundnut, mustard or Ghee can be recommended .

Don’t reuse or reheat your cooking oil.

Ensure that there is no visible smoke while frying.

Avoid stocking oils for longer periods.

If your oil smells different or bad, avoid using it.

“On the basis of composition, no oil can be tagged as the best, rather different kinds of oil should be used in rotation to have taste and benefits of all kinds of composition.”

– Dietitian and Wellness Expert Shilpi Goel