QUICK! Answer this question: What’s the first ingredient you use as soon as you start cooking? The answer definitely has to be oil.
Vegetable oils are extracted from plants, nuts, seeds and fruit. These oils are also known as plant oils because they are all plant-based. Vegetable oils are made up of three primary, essentially fatty acid compounds, called polyunsaturated fat, monounsaturated fat and saturated fat.
Depending on the type of plant, their percentage of the three fatty acids differ – i.e. some oils are higher in monounsaturated fat, whereas some are higher in polyunsaturated fat and some in saturated fat.
Sometimes, manufacturers mix different vegetable oils together. Read the ingredient list of the vegetable oil to determine the oils present.
Our body needs all these essentially fatty acids from our foods as our body cannot make them on their own. So when you add vegetables oils to your foods, you are inevitably getting nutrients that our body requires. One tablespoon of vegetable oil has an average of 120 calories and 15 grammes of fat.
Vegetable oils are pure fat, so they do not provide us with any carbohydrates, protein, sodium or fibre. Vegetable oils are also a source of Vitamin E.
All vegetable oils are also cholesterol-free. Cholesterol is only present in animal meat and byproducts from animals such as eggs and milk. There is no cholesterol in plants.
You will notice that many brands of cooking oils will have “cholesterol-free” boldly splashed on their packaging label. That’s true, but don’t think that “cholesterol-free” means “Fat-free”. Oils are pure fat. So they are definitely not fat-free. Just to remind you, one tablespoon of vegetable oil will give you 15 grammes of fat. So, a little goes a long way!
If you are stir-frying a dish, one to two tablespoons of oil is more than enough. Use oil like how you would herbs and spices — to add layers of flavour to your foods — and not as a means to avoid the ingredients in your pan from sticking to its bottom!
Research shows that vegetable oils that are high in monounsaturated and polyunsaturated fatty acids may help to reduce the risk of heart disease and stroke by reducing related risk factors such as your total cholesterol level, LDL cholesterol (the bad cholesterol), blood pressure and cell inflammation.
OILS AND HEAT
When cooking, oils react to heat differently. Some oils are able to withstand a higher temperature, whereas others cannot. This is known as the oil’s smoking point.
The “smoke point” is the temperature at which the oil compounds start to break down. Soya bean, palm, peanut and sesame seed oils all have a high smoking point. They are for deep-frying.
Oils with a lower smoking point, such as walnut and flaxseed oils, are better used in making salad dressings, dips or gently tossed into cooked foods as a finishing oil. Oils that have been used and broken down should ideally be discarded, as they give out a bitter after-taste and have lost some of their nutritional value.
When storing oils, remember that light and heat will cause the oil’s compounds to degrade. This lessens their nutritional content over time. So don’t place them on out the kitchen counter by the stove (which is the typical place most people tend to put their bottle of oil). Oils are best stored in a dark, cool place away from direct sunlight such as in a kitchen cabinet or pantry.
Give the oil a sniff too once in a while. Throw it away if it smells off or is past its expiration date. Some oils that have a high polyunsaturated fatty acid content such as grape seed or walnut oil turn rancid faster than other oils. Store these oils in the refrigerator to extend their shelf life. Depending on your frequency of your usage, you may want to buy small bottles of oil so they don’t go to waste.
Oils add flavour and nutrition to dishes.
Let’s take a look at the various vegetable oils that add wonderful flavour and nutritional goodness to our foods to help us eat well.
Soya bean oil
This is mainly a polyunsaturated fat, and also has some monounsaturated and saturated fat. It has a mild neutral flavour and is commonly used as an all-purpose cooking oil.
This has a high amount of monounsaturated fatty acids, which make it a heart-healthy oil. Olive oil that is “light” means that it has a lighter colour and flavour. Don’t get confused and think that it has less fat. The fat content of a regular olive oil and “light” olive oil is exactly the same. Extra-virgin olive oil has a stronger aroma and is less acidic that regular olive oil. Olive oil can be used to lightly sauté fry meats, vegetables, as a dressing or as a dip.
This contains mainly monounsaturated fats and has Vitamin E. Due to its high smoking point, it’s often used for deep-frying and high heat wok-frying, as they do in Chinese restaurants.
This has a mild, neutral flavour and is higher in polyunsaturated fat. Corn oil is commonly used in baking, stir-frying or to lightly saute.
As its name implies, grapeseed oil is extracted from the seeds of grapes. It’s rich in polyunsaturated fat. Grapeseed oil only has a moderate smoking point, so it’s best used for light sautéing or quick stirfries. Do try it in your salad dressing or drizzled over steamed vegetables as a finishing oil.
It is made by cold-pressing dried walnuts. Walnut oil has alpha-linolenic acid, which gets converted in your body to Omega 3 fatty acid. Alpha-linolenic acid is primarily found in plants, and it is similar to the omega-3 fatty acids that are in cold-water fish such as salmon, mackerel and tuna. Other types of cooking oils that are good sources of this type of alpha-linolenic acid include flaxseed oil and canola oil too.
Pumpkin seed oil
This exotic sounding oil has a nice rich deep-yellow colour. Its flavour is also rather nutty, which gives your dish a robust flavour. Like walnut oil, pumpkin seed oil also contains alpha-linolenic acid.
This is extracted from the fruit of fully mature coconuts. It has a predominantly saturated fat content – hence it tends to be solid at room temperature. Virgin coconut oil is high in a type of fat called lauric acid, which is a type of medium chain fatty acid. This type of fatty acid is more easily absorbed and converted to energy. Coconut oil’s nutty flavour is often used as a substitute for butter for vegans who do not consume dairy.
This is a natural source of Vitamin E and carotenoids, which is a type of antioxidant. Palm oil is predominantly made up of saturated and monounsaturated fatty acids. It adds a rich, earthy taste to our foods. With a high smoking point, palm oil is suitable for deep frying of foods.