There is only one benefit of eating camellia oil, and it’s different from what you think!

Camellia oil is a nutritious cooking oil, and its nutritional value is comparable to that of olive oil, so it is known as the "Oriental Olive Oil". 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 cooking and frying? How to choose and use camellia oil? In this article, let us learn about the unique charm of camellia oil.

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What is Camellia Oil?

What are the nutritional characteristics?

Camellia oil, also known as camellia seed oil and tea seed oil, is obtained from the mature seeds of camellia oleifera through pressing and extraction. It is one of the unique and oldest woody edible vegetable oils in my country.

1

Rich in monounsaturated fatty acids

Camellia oil is rich in monounsaturated fatty acids (MUFA), of which oleic acid content is as high as about 80%. MUFA can help lower the level of bad cholesterol in the blood, thereby helping to reduce the risk of heart disease and stroke.

For example, the energy supply ratio of fat in the Mediterranean diet is as high as 40%, but their blood cholesterol and cardiovascular disease incidence rates are much lower than those in other European and American countries. Researchers attribute this to the MUFA rich in olive oil.

According to the national standards GB/T23347-2021 and GB/T11765-2018, MUFA accounts for 56.4%~87.6% and 69.9%~88.9% of the total fatty acids in olive oil and camellia oil, respectively.

It seems that the upper limit of MUFA of the two is similar, but the lower limit of MUFA of camellia oil is much higher than that of olive oil. The lower limit is the minimum requirement of the national standard for products. What are the actual MUFA levels of commercially available olive oil and camellia oil?

I searched for 4 best-selling olive oils and camellia oils respectively and found that the olive oil with the lowest MUFA content has 68.5g/100g MUFA, followed by 72g/100g. However, the camellia oil with the lowest MUFA content also contains 79.5g/100g MUFA. It seems that camellia oil has more advantages than olive oil when it comes to supplementing MUFA.

However, the current fatty acid intake of Chinese residents is not too lacking in oleic acid, so there is no need to supplement oleic acid. However, soybean oil, corn oil, and sunflower oil, which are commonly used for cooking and frying, are not only more unstable at high temperatures, but also contain more n-6 fatty acids that promote inflammation. Although n-3 fatty acids are anti-inflammatory, n-3 fatty acids are not heat-resistant, so oils rich in them, such as linseed oil, are not easy to heat. Therefore, from the perspective of edible oil, it is still recommended to use more oils rich in monounsaturated fatty acids, such as camellia oil, in cooking 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 accompaniments, and does not contain ingredients such as behenic acid and erucic acid that are difficult for the human body to digest and absorb, nor does it contain aflatoxin.

Among them, plant sterols can compete with cholesterol and reduce its absorption into the blood, so they are beneficial to cardiovascular health; vitamin E, squalene, polyphenols, flavonoids, and proanthocyanidins can all be antioxidants. Because excessive oxidative stress is closely related to aging, tumors, infectious diseases and many other diseases, the intake of these ingredients is also beneficial to health.

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Can cold-pressed camellia oil be used for cooking and frying?

Since cold-pressed camellia oil contains various bioactive ingredients, most of which are afraid of heat, is it suitable for high-temperature cooking (such as stir-frying or frying)?

Let me give you the answer first: Camellia oil is relatively stable when heated, and it is fine for stir-frying or deep-frying at oil temperatures below 180°C, but it is recommended not to wait until the oil smokes before adding food, and try to avoid repeated frying.

There are three specific reasons:

1. The monounsaturated fatty acid content of camellia oil is much higher than that of the oils we usually use for cooking, such as soybean oil, corn oil, sunflower oil, and peanut oil. Monounsaturated fatty acids are more stable than polyunsaturated fatty acids, and are less likely to be oxidized into hydrogen peroxides that can damage human DNA and cell structure at high temperatures.

2. About 99% of vegetable oil is 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 that is beneficial to our health. As for various biologically active ingredients, being able to ingest a little bit of them is a plus. Besides, various dark-colored fruits and vegetables can also supplement a lot of antioxidants, so we don't necessarily have to rely on eating oil to supplement them.

3. From a nutritional point of view, it is a pity that high temperature heating will cause the loss of heat-sensitive active ingredients, but from a safety point of view, this is a good thing, because their antioxidant capacity can protect fatty acids and make them less likely to be oxidized at high temperatures. Let's take a look at the following study.

The study heated 2 liters of three kinds of oil with different degrees of refinement to 180℃, and started frying after stabilizing for 30 minutes. Each batch of potato strips was fried for 50 grams, and the potatoes were removed from the pan after 4 minutes. Then, the oil temperature was allowed to return to 180℃ after 6 minutes and frying continued. In this way, 6 batches of potato strips were fried every hour, and the debris in the pan was cleaned out after 4 hours and frying continued. The frying lasted for 8 hours a day, for a total of 28 hours, and not a drop of new oil was added during the process.

The results showed that compared with refined camellia oil, when frying potato strips with camellia oil rich in various active ingredients, the oil is not only less likely to be oxidized, but also less likely to undergo hydrolysis and polymerization reactions, and generates fewer lipid hydroperoxides that are harmful to health, and fewer free fatty acids that are more easily oxidized and rancid. In addition, frying does not destroy all bioactive ingredients. At the end of frying, the polyphenols and total sterols in the camellia oil were retained by 17% and 56%, respectively.

Low-temperature cold-pressed camellia oil is obtained by filtering crude oil to remove impurities. It has a high content of biologically active ingredients and can naturally be used for cooking and frying. Think about the Mediterranean diet, which also uses extra virgin olive oil for frying and baking. So we can use cold-pressed camellia oil for frying and stir-frying with confidence.

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How to choose and consume camellia oil?

1

Choose first-grade camellia oil

This is because the national standard GB/T11765-2018 stipulates that the moisture content, volatile matter content and acid value of first-grade camellia oil are lower, and such oil is more stable.

2

Prefer cold pressed rather than hot pressed or leached

This is because the tea seeds are not steamed or fried during cold pressing, but directly pressed, and the pressing temperature will not exceed 60°C, while the tea seeds need to be steamed or fried first during hot pressing, with the temperature reaching above 100°C, and the temperature of some frying will reach above 250°C. Then, during pressing, the temperature of the pressing chamber of some screw pressing can be as high as 200°C, which will seriously lose the bioactive ingredients. In addition, cold-pressed camellia oil does not need to be refined, and only needs to be filtered to achieve edible quality, while hot-pressed and leached camellia oil must be refined (some steps are high temperature), which will further lose the bioactive ingredients. For example, research has found that when the deodorization temperature of crude oil reaches 210°C, the squalene loss rate is as high as 53.7%, as shown in the figure:

In addition, without the protection of these active ingredients, not only is the oil less stable during cooking (as mentioned in the previous study on fried potatoes), but the stability of the oil during storage is also lower. Studies have shown that compared with cold-pressed camellia oil, the acid value and peroxide value of refined camellia oil increase more significantly during storage. The higher these two indicators are, the easier it is for the oil to oxidize and become rancid.

3

Choose small packaging

It is best for a family of three to buy less than 1 liter, and for a family of six to buy less than 2.5 liters. This is because once the package is opened, the oxidation and rancidity of fatty acids will be accelerated.

Finally, 3 points

1. Control the amount of consumption. No matter how healthy the oil is, 1 gram will produce 9 kcal of energy. Eating too much will make you fat, so it is recommended to eat it in exchange with other oils. It is enough for each person to eat 25 to 30 grams of all the oils per day.

2. Don’t wait until the oil starts to smoke before putting the food in. Compared to refined camellia oil, cold-pressed camellia oil does have a lower smoke point, so you have to be quick and put the food in before the oil starts to smoke, because the oil smoke contains a variety of ingredients that may cause cancer.

3. Fry less and avoid repeated frying. If you fry, it is best to control the oil temperature as in the study (for example, use a thermometer and turn down the heat when the oil temperature is high), and don't fry like the roadside stalls, where you can always see a puff of black smoke; in addition, no matter how much you fry, it will produce ingredients that are harmful to health, such as carcinogens such as 3,4-benzopyrene and acrylamide, and the energy of food will soar after frying, so try to fry less and avoid repeated frying. It is recommended to use the oil used for frying to mix cold dishes or make dumplings/steamed buns.

In general, camellia oil has excellent nutritional content and is both stable and cardiovascular-friendly, but it is also relatively expensive, so many friends are reluctant to put too much in it when eating. From this perspective, camellia oil can also promote oil reduction to a certain extent. Therefore, without considering the price factor, it is a good choice among cooking oils. This is the real reason why we recommend everyone to eat camellia oil.

References

[1] https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/monounsaturated-fats

[2] Chinese Nutrition Society. Dietary Reference Intakes of Nutrients for Chinese Residents (2023 Edition)[M]. Science Press, 2023:153

[3]HuangCH.[StressMedicineandHumanHealth].SichuanDaXueXueBaoYiXueBan.2021Jan;52(1):1-4.Chinese.doi:10.12182/20210160501.PMID:33474880;PMCID:PMC10408951.

[4] Tan Chuanbo, Tian Hua, Zhou Gangping, et al. Comparison of nutritional value of freshly squeezed camellia oil and extra virgin olive oil [J]. China Oils and Fats, 2019(1):3.

[5] Tan Chuanbo, Lai Qiongwei, Yang Yaoxue, et al. Study on the extraction technology of fresh camellia oil[J]. China Oils and Fats, 2018, 43(8):3.

[6] Tan Chuanbo, Tian Hua, Lai Qiongwei, et al. Comparison of the content of bioactive substances in camellia oil produced by different processes [J]. China Oils and Fats, 2018, 43(12): 41-44+49.

[7] Chinese Nutrition Society. Dietary Guidelines for Chinese Residents[M]. People's Medical Publishing House, 2022:106

[8] Chan Jianquan. Food Chemistry (Second Edition)[M]. Beijing. China Agricultural University Press, 2008:175

[9] Hou Tianyu, Xie Liwen, Liang Yongxia, et al. Study on the quality changes of camellia oil with different refining degrees during frying [J/OL]. Journal of the Chinese Cereals and Oils Association, 1-14 [2023-12-15]

[10] Chen Leyi, He Xiaohong, Dai Taotao, et al. Effect of refining process on accompanying substances in pressed camellia oil[J]. Food Industry Science and Technology, 2022, 43(06): 221-227.

[11] Zeng Jing, Wang Weifei, Chen Ying, et al. Quality changes of camellia oil prepared by different processes during storage[J]. China Oils and Fats, 2023, 48(11): 8-13+24.

This article is a work of Science Popularization China-Starry Sky Project

Produced by: Science Popularization Department of China Association for Science and Technology

Producer｜China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

Author: Gu Chuanling, Deputy Secretary General of Capital Health Nutrition and Gastronomy Association, Registered Nutritionist

Review | Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center