Canola oil

Canola oil, also known as rapeseed oil, has a relatively healthy ratio of fatty acids. Cold-pressed canola oil contains high amounts of omega-3 fatty acids and a balanced ratio of polyunsaturated fatty acids. Canola oil is obtained from the seeds of rapeseed, also known as canola (Brassica napus).

Culinary uses:

Cold-pressed canola oil is amber to honey-colored and has a mild, slightly nutty taste. It is best used unheated, for example, in salad dressings, vegan mayonnaise, dips, marinades, and with raw vegetables, as well as to improve cooked dishes. Virgin canola oil has a lower smoke point than refined canola oil and can be used for cooking at low temperatures, such as gentle steaming. Virgin canola oil breaks down when heated to temperatures above 140 °C.¹ In order to retain canola oil’s valuable nutrients and to prevent hazardous decomposition products from developing (such as trans fats), you should avoid heating cold-pressed canola oil, or heat it gently at most.

Refined canola oil is light yellow, flavorless, and suitable for a wide range of uses. In cooking, it can be used for baking and frying at lower temperatures up to about 180 °C.² Be careful not to heat refined canola oil too high. According to Wikipedia, canola oil has a smoke point of approximately 220 to 230 °C. If the oil smokes, it is already too hot.¹

Is canola oil suitable for frying? High-oleic low-linolenic canola oil contains natural colors and flavors, and is ideal for shallow frying, deep-frying, boiling, steaming, and baking at temperatures of up to approximately 210 °C.³ If canola oil is heated above its smoke point, you should throw it away as hazardous decomposition products such as trans fats, peroxides, and acrylamide begin to form at the smoke point. At this point, vitamin E and canola oil’s polyunsaturated fatty acids also begin to break down oxidatively and thermally.¹ In general, we recommend avoiding high-heat cooking. Instead, try steaming your vegetables gently or eating them raw. A raw food diet allows you to completely avoid consuming harmful trans fats and Maillard molecules.

Vegan recipe for Mayonnaise with Cold-Pressed Canola Oil:

To make homemade mayonnaise, all ingredients need to be at room temperature. Mix 200 mL unsweetened, unflavored soy milk with 3 teaspoons mustard and 4 teaspoons lemon juice. Gradually add 250 ml cold-pressed canola oil, mixing constantly until it develops a creamy, firm consistency. Season the mayonnaise to taste with salt, pepper, agave syrup, and vinegar.

Purchasing — where to shop:

Is canola oil cold pressed? Canola oil is available in different grades and price ranges from most major supermarkets including Walmart, Whole Foods Markets, Kroger, and Safeway (United States); Extra Foods, Metro, and Freshmart (Canada); Asda, Sainsbury’s, Tesco, Aldi, and Lidl (Great Britain); and Woolworths, Coles, Aldi, and Harris Farm (Australia). It can also be found in organic supermarkets, health food stores, and online. Canola oil is grown and pressed in many countries throughout the world, making it an environmentally friendly choice if you buy domestically grown canola oil as this eliminates long transport routes.²

Cold-pressed canola oil is pressed using an expeller — a mechanical method for extracting oil from various raw materials as gently as possible without heat. However, the raw materials may undergo heat treatment before they are processed.^4,5

Virgin canola oil is a natural oil that is produced from canola that has not been preheated. It is cold-pressed or produced using other mechanical processes without heat.^4,5

“Extra virgin” is the highest grade of oil quality in the European Union. Extra virgin canola oil means that the canola oil has been pressed and is of particularly high quality.⁴

“Unrefined” canola oil usually indicates that the oil has been made by slightly heating canola seeds, or through gentle mechanical processes such as pressing and centrifuging. Unrefined canola oil may be steamed to increase its shelf life and reduce undesirable by-products that the oil may contain.^5,6

High-oleic low-linolenic canola oil comes from special varieties of canola that have been selectively bred to contain a higher content of oleic acid and a lower content of omega-3 fatty acids. The canola seeds are cold-pressed and then treated with steam. Throughout this process, the seeds retain their natural colors and flavors.³

Mainstream canola oil is made through hot pressing and chemical extraction using solvents. During the refining process, undesirable by-products are removed to create an odorless, neutral-flavored oil.⁶

Canola kernel oil is made from hulled canola seeds, whereas canola oil is made from unhulled seeds. This is why cold-pressed canola oil has a particularly mild flavor.⁷ The Deutsche Gesellschaft für Fettwissenschaft (German society for the science of fat, DGF) tests domestically grown canola oils, and since 2006 has awarded an annual medal for excellent tasting canola oil.⁷

Storing:

Cold-pressed canola oil is sensitive to heat, light, water, oxygen, and odors. It contains a high content of polyunsaturated fatty acids, which means it is essential to store it in a cool, dark place in an airtight bottle or container. Opened canola oil is best stored in the fridge and should be consumed within four to eight weeks. It should be stored in containers that are as full as possible, as the less oil there is in the container, the more oxygen the oil will be exposed to, thus leading to the oil spoiling through oxidization. Cold-pressed canola oil that has not yet been opened keeps for about six months to a year, provided that it is stored in a cool, dark place. You can tell that canola oil is off if it has a rancid flavor.^8,9

Refined canola oil and high-oleic low-linolenic canola oil must also be stored in a well-sealed container in a cool, dark place. If the oil has not yet been opened, it keeps for about two years.

Nutrients — nutritional information — calories:

Canola oil is made up of a variety of fatty acids. It contains the following fatty acids: 51–70 % oleic acid, 15–30 % (19 g/100 g) linoleic acid (omega-6 fatty acids, LA), 3–12 % (9.1 g/100 g) alpha-linolenic acid (omega-3 fatty acids, ALA) and 7.4 % saturated fatty acids. Canola oil has a ratio of omega-6 fatty acids to omega-3 fatty acids of 2:1 (LA:ALA). According to the Swiss Federal Commission for Nutrition (EEK), a healthy daily ratio of omega-3 to omega-6 fatty acids should not be more than 5:1.^9,10 Other oils have far less favorable ratios. Olive oil has a ratio of 12:1 and grape seed oil a ratio of 696:1, while sunflower oil, peanut oil, and safflower oil contain practically no omega-3 fatty acids.

Higher levels of omega-3 fatty acids are found in flaxseed oil (53 g/100 g), hemp oil (16 g/100 g), and walnut oil (10 g/100 g). This makes these oils even more difficult to store. They also contain healthy ratios of omega-6 fatty acids to omega-3 fatty acids (5:1 for walnut oil, 4:1 for hemp oil, and 1:4 for flaxseed oil).¹⁰

According to the Swiss supermarket chain Migros, high-oleic low-linolenic canola oil contains a better LA:ALA ratio than olive oil.¹⁶

In the past, oil made from rapeseed contained erucic acid, an omega-9 fatty acid that is harmful for one’s health. Today, however, canola oil contains very little erucic acid (0–2%). Through selective breeding, undesirable elements of rapeseed could be removed over time, including erucic acid and glucosinolates (mustard oil glycosides). This has led modern varieties of oilseed rape to be referred to as “double zero” or “00” varieties.^9,10

Virgin canola oil contains vitamin K and vitamin E (17 mg/100 g) as by-products. Vitamin E acts as a natural antioxidant and protects canola oil from spoiling. However, an average of 10 % of canola oil’s vitamin E is lost during cooking through oxidization. There are other foods that are richer in vitamin E, including unshelled hemp seeds (90 mg/100 g), almonds (25.6 g/100 g), and hazelnuts (15 g/100 g).^1,10

You can find detailed nutritional information in the tables below the text.

We believe that canola oil is a superfood thanks to its good ratio of fatty acids and the fact that it contains the antioxidant vitamin E. Oils and fats should be enjoyed in moderation. Some prominent doctors in the United States, especially cardiac specialists, strongly believe that we should try to eat a diet that does not contain oil. No oil is healthy since like white sugar it has an unnatural concentration of fat. You can easily eat enough seeds and nuts to meet your daily intake of fatty acids and vitamins.

Health aspects — effects:

How healthy is canola oil? Canola oil not only contains polyunsaturated fatty acids that can lower the amount of LDL cholesterol (LDL = low density lipoprotein) found in blood, it also contains monounsaturated oleic acid, which can also help to lower LDL cholesterol. Oleic acid has a chemical structure of a single double bond, which means that the body incorporates it into LDL particles. Oleic acid is less prone to oxidization, leading to less plaque formation in the arteries and lowering the risk of arteriosclerosis.⁹

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are two types of omega-3 fatty acids that have antithrombotic, anti-inflammatory, bronchodilator, and vasodilator effects.¹¹

The answer to the question “what is the healthiest oil?” basically depends on the quantity of oil used, how the oil will be used, and the ratio of fatty acids in the dish that is to be cooked. Some vegetable oils and fats should be avoided, and others should be used if you are combining oil with other whole foods such as nuts, seeds, olives, and avocados. If you are looking for oils for cold dishes, we recommend high-quality, cold-pressed canola oil, flaxseed oil, and walnut oil. For cooking with gentle heat, high-oleic low-linolenic canola oil¹⁶ and olive oil are ideal, as they remain more stable when heated. Oils with a high content of omega-6 fatty acids should be avoided, including sunflower oil, peanut oil, grape seed oil, and safflower oil. Palm oil and coconut oil should equally be avoided because they are rich in saturated fatty acids.¹²

Dangers — intolerances — side effects:

Consuming excessive amounts of polyunsaturated fatty acids (whether through oil, food supplements, or eating products with added fats) leads to the increased formation of potentially toxic products from oxidization. However, consuming a natural diet with lots of fresh fruits and vegetables provides your body with lots of antioxidants that make oxidation products harmless. Vitamin E plays a particularly important role in the neutralization of lipid peroxide radicals.^9,12

Rapeseed that has not been selectively bred contains high amounts of erucic acid, accounting for more than half of the total fatty acids that canola oil contains. Erucic acid is harmful for one’s health, causing organ damage and heart problems in humans and mammals. Luckily, canola oils that are consumed today contain hardly any erucic acid.^7,13 According to the European Food Safety Authority (EFSA), the average consumer is exposed to between 0.3 and 4.4 mg/kg erucic acid per day. Such exposure usually occurs through eating pastries, cakes, biscuits, and in the case of infants through infant formula.¹⁴

If canola oil is heated, the fatty acids transform and break down. When temperatures reach about 140–150 °C and above, unsaturated fatty acids are transformed into potentially harmful trans fatty acids. Higher contents of polyunsaturated fatty acids promote the formation of trans fat. When cold-pressed or refined oils are used for standard kitchen cooking, there is an average increase in trans fatty acids from 0.02 % or 1.5 % up to 2 % (measured in an experiment over a frying time of 54 hours). Trans fatty acids generated by refining oils account for an average of 1 % of total fatty acids. Current knowledge suggests that trans fatty acids that form through cooking at standard kitchen temperatures are at such low levels that they are not significant enough to be relevant.¹

Description — origin:

According to Wikipedia, rapeseed originally came from the eastern Mediterranean region. Rapeseed has been grown for the purpose of extracting oil for centuries and was used as early as Roman times.² However, rapeseed oil used to contain a high proportion of bitter compounds such as glucosinolates (also known as mustard oil glycosides). It also contained potentially dangerous acids such as erucic acid, eicosenoic acid, gadoleic acid, and nervonic acid. As a result, rapessed oil was initially used mainly as lamp oil, lubricant, and soap, and hardly ever consumed.⁷

In the late 1960s, varieties of rapeseed containing low levels of erucic acid and other bitter compounds were successfully bred from Brassica rapa subsp. oleifera, a variety of oilseed rape closely related to Brassica napus (today’s canola). In the 1970s, rapeseed 0 was developed, and in the 1980s rapeseed 00 (canola) was further developed. This is a major reason that rapeseed oil is now referred to as canola — for marketing reasons, edible canola oil was distinguished from previously “toxic” rapeseed oil. Canola was developed in Canada, and the name Canola comes from contracting the words Canda and Ola (oil).¹⁸ Today, nonedible varieties of rapeseed oil are referred to as colza oil.

Various types of rapeseed are among the most important oilseed plants worldwide. Different types of rapeseed contain different amounts of fatty acids, which depend on their intended use. For example, high erucic acid rapeseed is grown to produce erucic acid as a raw industrial material. This is a variety of rapeseed that is rich in erucic acid but low in glucosinolate.⁷

Cultivation — harvest — processing:

In Europe, canola is grown almost exclusively in winter, while very small quantities are grown in summer (372,000 hectares in 2007).

In 2008/09, the global rapeseed harvest was approximately 54.1 million tons, about four times higher than in the early 1980s (12.7 million tons).^7,13

Areas where High Erucic Acid Rapeseed (HEAR) is grown to produce erucic acid for industrial use are contaminated with volunteer rapeseed. This type of rapeseed may no longer be grown for human consumption.⁷

According to the Food and Agriculture Organization (FAO), global rapeseed oil production amounted to 25.9 million tons in 2014, making it one of the three most produced vegetable oils in the world, alongside palm oil and soybean oil. It is estimated that canola oil production accounted for 14.5 % of total vegetable oil production in 2008/09.⁷

Animal protection — species protection — animal welfare:

Canola is considered one of the most important agricultural crops in the world. The plant flowers in May, which is why it is important spring nectar for bees and insects. Bees collect nectar, pollen, and honeydew. Rapeseed contains high amounts of nectar and pollen.¹⁵ Canola plants produce bright yellow flowers with four petals in a typical cross form. Each flower produces approximately 0.4 to 2.1 mg in 24 hours.¹³

General information:

Canola oil is a vegetable oil obtained from the seeds of canola (Brassica napus) or, more rarely, from the seeds of turnip rape (Brassica rapa subsp. oleifera). The two oilseeds are closely related and belong to the Brassicaceae family (Cruciferae or cabbage family).⁷

Low-erucic rapeseed varieties (rapeseed 0) contain small amounts of erucic acid. Oil from canola (rapeseed 00) contains about 0.5–1.5 % erucic acid and is the main type of canola oil produced today. It is also low in glucosinolate.

Lauric canola oil comes from genetically modified canola plants (Laurical) and is rich in monounsaturated oleic acid and medium-chain lauric acid.⁹

High-oleic canola has an increased oleic acid content. High-oleic low-linolenic canola is used to produce edible canola oil. It also contains an increased proportion of monounsaturated oleic acid, with a reduced content of omega-3 fatty acids. This increases the shelf life and heat stability of the oil.⁷

High erucic acid rapeseed contains up to 55 % erucic acid. Erucic acid is extracted from rapeseed mechanically.⁷

Alternative names:

Canola oil is also referred to as canola, rape, rapeseed, oilseed rape, colza, and coleseed.

Keywords for use:

In 2007, three-quarters of the rapeseed oil produced in Germany was used for the production of biofuels or industrial use.¹³

Technical and material uses in the chemical industry include biofuel, vegetable oil fuel, biodiesel, hydraulic oil, gear oil, chainsaw oil, cutting fluid, hardening oil, black annealing, bluing processes, motor oil, formwork oil, lacquer, paints, solvents, surfactants, softeners, animal feed, pesticides, rapeseed asphalt, candles,⁷ bioplastics, and biogenic lubricants.¹³

Uses in the pharmaceutical and cosmetic industry include medical ointments and cosmetic formulations.⁷

By-products of canola oil production include canola cake, by-products from expeller pressed canola oil, and rapeseed meal extraction, an animal feed rich in protein.

Nutrient tables

The complete nutritional information, coverage of the daily requirement and comparison values with other ingredients can be found in the following nutrient tables.

Literature — sources:

Author: Kerstin Gackle | 8 Mar 2017