Not all oils perform well under high temperatures. Tan Bee Hong finds out that palm oil has a high smoke point which makes it a stable oil for deep frying
FRIED chicken, banana fritters, keropok lekor... what do these three top favourite foods on the local menu have in common?
They are all deep fried foods of course. But they are not the only ones. We deep fry lots of other items too — from potato and tapioca chips to curry puffs and tempura.
Why do we love deep fried foods? For one thing, the colour of deep fried food is an appetising golden brown. Secondly, there’s the crispy texture. Thirdly, frying in oil enhances the aroma of the foods.
Cooking food by immersing them in hot oil or fat is practised all over the world.
But not all oils are suitable for deep frying. Some oils are not stable. When heated, different cooking oils react differently as they break down and eventually start to smoke (also known as smoke point).
When a particular oil is said to have a high smoke point, this means it can be heated to a relatively high temperature before it starts to smoke. Some oils perform better for high heat cooking, like sauteeing or deep frying and some don’t.
Generally, vegetable oils have higher smoke points than animal fats (lard, butter). But oils such as olive oil has a low smoke point. Also, refined oils have higher smoke points as the process of refining removes impurities that causes oil to smoke.
But why is it important to have a high smoke point? At smoke point, oil breaks down, gives off an unpleasant, putrid odour and when food is cooked with this, it takes on an unsavoury flavour.
When oil reaches smoke point, there is also the danger of it catching fire and erupting into flames.
USE AND DISCARD
After deep frying, discard whatever oil is left. It is not advisable to reuse the oil. No, it’s not because used oil is “dirty” but rather, when oil is exposed to heat for a long time, the smoke point is lowered.
In the process of deep frying, bits of food such as batter or bread crumbs (used to coat food such as chicken) inevitably break off and get into the oil. These impurities will lower the smoke point.
GREAT FOR FRYING
Palm oil has one of the highest smoke point of all oils, at 235°C. Here’s how it compares with some popular oils:
Virgin olive oil 210°C
Corn oil 232°C
Sunflower oil 199°C
Sesame oil 232°C
Rice bran oil 245°C
Coconut oil 250 °C
Soya oil 210°C
An interesting observation about frying with palm oil is that its high smoke point means food deep fried in it will absorb less oil.
PACKED WITH GOODNESS
Palm oil is also high in nutrient content, highly resistant to oxidation and suitable for all methods of food preparation, from deep frying, stir frying to roasting and baking. It is also a good choice as a salad oil. There is no need to keep different types of oils in your larder as palm oil will meet all your cooking requirements.
Produced from the fruit of the oil palm (Elaeis guineensis), it contains a variety of fats, vitamins and nutrients, with no unhealthy trans-fatty acids that is found in hydrogenated oils.
Palm oil is free of artery-clogging trans-fats as it is made up of a balanced mix of fatty acids containing vitamins A and E and nutrients our bodies need. It contains 40 per cent oleic acid and 10 per cent linoleic acid, which are monounsaturated fatty acid and polyunsaturated fatty acid respectively. Those are the good fats and like it or not, our bodies require fat.
Palm oil is a rich source of carotenoids and vitamin E which makes it stable against oxidative deterioration. Unrefined palm oil and crude palm oil are nature’s richest source of carotenoids as compared to the other vegetable oils — 15 times more than carrot, and 300 times more than tomato.
Unlike other vegetable oils, palm oil is the only one containing the full spectrum of Vitamin E (tocopherols and tocotrienols). The lesser known form of vitamin E, tocotrienols, are powerful anti-oxidant that kills free radicals in the body. This helps lower the risk of certain chronic diseases and delay the body’s ageing process.
Studies by Dr Paul Sylvester, Professor of Pharmacology and director of Graduate Studies and Research at the College of Pharmacy, University of Louisiana, on the health benefits of palm oil show it has anti-cancer properties and the fatty acids of palm oil can inhibit and/or delay experimental carcinogenesis.
When red palm oil is refined and processed, some of the carotenes are lost but not the tocotrienols and other nutrients.
Oil palm trees (Elaeis guineensis jacq.) originates from West Africa. They were introduced to Malaya by the British in 1870 but as an ornamental plant. In 1917, the first commercial planting of oil palm was in Tennamaran Estate in Selangor. Today, the oil palm is the leading agricultural crop in the country (about 15 per cent of landmass), spanning across five million hectares.
The oil palm is the most efficient oil-bearing crop in the world. It requires only 0.26 hectares of land to produce one tonne of oil while soya bean, sunflower and rapeseed require 2.22, 2 and 1.52 hectares, respectively, to produce the same amount of oil.
Indonesia and Malaysia are the largest producers and exporters of palm oil in the world, accounting for two thirds of the world’s vegetable oils and fats shipment.
The oil palm tree produces compact bunches of fruit weighing up to 25kg each. Each bunch has about 1,000 to 3,000 small, dark purple to orange red (when ripe) fruitlets comprising a hard kernel (seed) enclosed in a shell (endocarp) which is surrounded by a fleshy mesocarp.
Both produce different types of oil but what we know as palm oil is that which is extracted from the mesocarp, so essentially, it is a fruit oil, not a kernel oil.
The oil yield from the fruit is high and as much as 5kg of oil can be obtained from a fruit bunch weighing 25kg.