Camellia oil is a nutritious cooking oil that rivals olive oil in terms of nutritional value, so it is known as the "olive oil of the East". There is only one benefit of eating camellia oil: it is too expensive and you have to eat less.
So, is camellia oil suitable for stir-frying and frying?How to choose and use camellia oil?Today's article, let's learn about the unique charm of camellia oil.
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What is camellia oil and what are its nutritional characteristics?
Camellia oil, also known as camellia seed oil and camellia seed oil, is the mature seed of Camellia oleifera through pressing, extraction and other processes, and is one of the most ancient woody edible vegetable oils unique to the mainland.
1. Rich in monounsaturated fatty acids
Camellia oil is rich in monounsaturated fatty acids (MUFA), of which the oleic acid content is as high as about 80%. MUFAs can help lower the level of bad cholesterol in the blood, which can be beneficial in reducing the risk of heart disease and stroke.
For example, the Mediterranean diet, which has a fat-to-energy ratio of up to 40 percent, has a much lower incidence of blood cholesterol and cardiovascular disease than other European and American countries, which researchers attribute to the fact that olive oil is rich in MUFA.
According to the national standards GB/T 23347-2021 and GB/T 11765-2018, MUFA accounts for 56.4%~87.6% and 69.9%~88.9% of the total fatty acids in olive oil and camellia oil, respectively.
In this way, the upper limit of MUFA for both is about the same, but the lower limit of MUFA, camellia oil is much higher than olive oil. The lower limit is the minimum requirement of the national standard for products, but what about the actual MUFA levels of commercially available olive oil and camellia oil?
I searched for 4 popular olive oils and camellia oils, and found that the olive oil with the lowest MUFA content was 68.5 g/100 g, followed by 72 g/100 g, but the camellia oil with the lowest MUFA content also contained 79.5 g/100 g MUFA, so it seems that camellia oil has more advantages than olive oil to supplement MUFA.
However, at present, the fatty acid intake of mainland residents is not too lacking in oleic acid, so there is no need to supplement oleic acid. However, like soybean oil, corn oil, and sunflower oil, which are commonly used for stir-frying, are not only more unstable at high temperatures, but also promote inflammation with more N-6 fatty acids, although N-3 fatty acids are anti-inflammatory, but N-3 series fatty acids are not heat-resistant, so oils rich in them such as flaxseed oil are not good for heating, so from the perspective of edible oil, it is still recommended to use more oils rich in monounsaturated fatty acids in cooking oils, such as camellia oil.
2. Strong ability to supplement bioactive ingredients
Cold-pressed camellia oil is also rich in fat-soluble vitamins, plant polyphenols, squalene, phytosterols and other fat concomitants, and does not contain behenic acid, erucic acid and other components that are difficult for the human body to digest and absorb, nor does it contain aflatoxins.
Among them, phytosterols can compete with cholesterol and reduce its absorption into the blood, so it is beneficial for cardiovascular health, and vitamin E, squalene, polyphenols, flavonoids, and proanthocyanidins can all be antioxidant, because excessive oxidative stress is closely related to aging, tumors, infectious diseases and other diseases, so the intake of these ingredients is also beneficial to health.
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Can cold-pressed camellia oil be stir-fried and fried?
Since cold-pressed camellia oil contains various bioactive components, most of which are sensitive to heat, is it suitable for high-temperature cooking (such as stir-frying or frying)?
Let's talk about the answer first: camellia oil is relatively stable when heated, and there is no problem with stir-frying and frying below 180°C, but it is recommended not to wait until the oil is smoking, and try to avoid repeated frying.
There are three specific reasons for this:
1. The monounsaturated fatty acid content of camellia oil is much higher than that of the oil we usually use for stir-frying, such as soybean oil, corn oil, sunflower oil, and peanut oil.
2. About 99% of the components of vegetable oil are fat, which means that the amount of active ingredients is actually very low, in other words, the main purpose of eating camellia oil or olive oil is to ingest MUFA, which is beneficial to health.
3. From a nutritional point of view, it is a pity that high temperature heating will lose the active ingredient that is sensitive to heat, but from a safety point of view, it is a good thing, because of their antioxidant capacity, which can protect fatty acids and make them less susceptible to oxidation at high temperatures. Let's take a look at the following study.
Research on three kinds of oil with different degrees of refining, respectively, 2 liters of heating to 180 °C, stable for 30 minutes before frying, each batch of 50 grams of potato strips, fried for 4 minutes, and then 6 minutes to let the oil temperature return to 180 °C before frying, so 6 batches of potato strips were fried every hour, 4 hours to clean up the debris in the pot and continue to fry, 8 hours a day, a total of 28 hours, no drop of new oil was added in the process.
The results showed that compared with refined camellia oil, when frying potato fries with camellia oil crude oil, which is rich in various active ingredients, the oil was not only less prone to oxidation, but also less prone to hydrolysis and polymerization, resulting in less lipid hydroperoxides that are harmful to health, and fewer free fatty acids that are more likely to oxidize rancidity. In addition, frying did not destroy all the bioactive components, and the polyphenols and total sterols in the crude oil of camellia oil were retained by 17% and 56% respectively at the end of frying.
Low-temperature cold-pressed camellia oil is obtained by filtering and removing impurities, and the content of bioactive ingredients is also high, so it can naturally be used for stir-frying and frying.
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How to choose and consume camellia oil?
1. Choose first-grade camellia oil
This is because the national standard GB/T 11765-2018 stipulates that the moisture, volatile content and acid value of first-grade camellia oil are lower, so the oil is more stable.
2. Prefer cold-pressed rather than hot-pressed or leached
This is because the camellia seeds are not steamed or fried when cold pressed, but directly pressed, and the pressing temperature will not exceed 60 °C, while the hot pressing needs to be steamed or fried first, the temperature is as high as 100 °C or more, and the temperature of some frying will reach more than 250 °C, and then the pressing temperature of some screw pressing can be as high as 200 °C, which will seriously lose the bioactive components; Some steps are high-temperature), which will further lose bioactive components, for example, studies have found that when the deodorization temperature of crude oil reaches 210°C, the loss rate of squalene is as high as 53.7%, as shown in the figure:
In addition, without the protection of these active ingredients, not only the stability of the oil during cooking is worse (as mentioned in the previous study of fried potatoes), but also the stability of the oil during storage, the study shows that compared with cold-pressed camellia oil, the acid value and peroxide value increase more significantly during the storage of refined camellia oil, and the higher these two indicators, the easier it is for the oil to oxidize rancidity.
3. Choose a small package
It is best to buy less than 1 liter for a family of three, and 2.5 liters for a family of six, because after the package is opened, it will accelerate the oxidative rancidity of fatty acids.
Finally, I would like to emphasize three points
1. Control the amount you eat. No matter how healthy the oil is, 1 gram will also produce 9 kcal of energy, and if you eat too much, you will be fat, so it is recommended to eat it with other oils, and all the oil per day, each person can eat 25~30 grams.
2. Don't wait until the oil is smoking. Compared with refined camellia oil, cold-pressed camellia oil does have a lower smoke point, so you have to be numb and eat when the oil is not smoking, because the smoke contains a variety of ingredients that may cause cancer.
3. Fry less and avoid repeated frying. If you fry deeply, it is best to control the oil temperature as in the study (such as using a thermometer, and turn down the heat when you find that the oil temperature is high), don't be like fried fritters at roadside stalls, you can always see a puff of black smoke; in addition, no matter how much you fry, it will produce harmful ingredients such as 3,4-benzopyrene, acrylamide, these carcinogens, and the energy of food will also soar after frying, so try to fry as little as possible, and avoid repeated frying, the fried oil is recommended to be used to mix cold dishes or make dumplings/buns.
In general, the nutritional content of camellia oil is very good, with both stable and cardiovascular-friendly characteristics, but its price is also relatively expensive, so many friends will be a little reluctant to put too much when eating, from this point of view, camellia oil can also promote oil reduction to a certain extent, so without considering the price factor, it is also a good choice in cooking oil, which is also the real reason why we recommend everyone to eat camellia oil.
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Planning and production
This article is a work of popular science China-Star Project
Produced by the Department of Science and Technology of the China Association for Science and Technology
Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Galaxy Culture Media Co., Ltd
Author丨Gu Chuanling, Deputy Secretary-General of the Capital Health Nutrition and Gastronomy Society, Registered Dietitian
Audit丨Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center