Does canola oil go bad? (+3 Nutritional facts)

In this brief introduction, we will address the question, “Does canola oil go bad?” as well as other questions pertaining to the subject at hand like how to store canola oil and how long it can last.

How Long Does Canola Oil Last

Canola oil lasts from 6 months to a year when opened. After opening, the oil should be kept in the refrigerator (2). 

Once you open the bottle, oil gets exposed to fresh oxygen which speeds up the oxidation process, resulting in the oil going rancid. However, that process is relatively slow, especially if you remember to keep the bottle sealed. After opening the bottle, you should finish it up within about 6 to 12 months for the best quality. A study showed that after 8 months of storage, most of the antioxidants (sterols and tocopherols) in rapeseed oil were lost, when the oil was not stored in the dark. The shelf life of canola oil can be extended when it is kept in the dark and under refrigeration (2).

Like all other oils (peanut oil, sesame oil, rapeseed oil) canola oil also comes with a best-by on the label, which is a rough estimate of how long the oil should retain freshness.

Of course, the way oil is stored affects how well it keeps its quality. If you store the canola oil properly, it should last longer than the best–by date without going rancid. It can easily go rancid before that date if kept in the open, exposed to sunlight. The better the storage, the longer it should last in good quality past the date on the label.

With 14% of oilseeds volume, rapeseed is the second world oilseed, but its volumes are dwarfed by soybean which represents 55% of the harvest. Nevertheless, for European agriculture this crop is the major oilseed, with a 2012 production of 19.5 Mt for a total production of 27.0 Mt (1).

What is canola oil?

Canola oil is one of the most vital ingredients in cooking. It has a lot of uses, especially as a flavour enhancer. Canola oil has a subtle flavour (if not neutral) and has a high smoke point (3).

It is claimed to be one of the healthiest culinary oil of all vegetable oils due to a low saturated fatty acids (6–7 %), and high contents of monoenoic (oleic acid 58–62 %) and polyenoic fatty acids, especially α-linolenic essential fatty acid (8–12 %). Moreover, rapeseed oil contains nutritionally favorable linoleic to α-linolenic essential fatty acids ratio of 2:1, as well as it is also marked by high concentrations of tocopherols and sterols (2).

Hence, this vegetable oil serves so many purposes and is suitable for stir-fry, sauté, deep fry, and baking. Canola oil also tastes great for salad dressing and marinade. You can also it is as:

Oil for baking, grilling, stir-frying food with carbon steel wok. In marinades, salad dressings, and sauces An alternative to solid fats like butter and margarine.

It is usually compared with olive oil because of their shared nuances and similarities. However, many people are somewhat confused as to whether this oil has an expiration date. Does canola oil go bad? How long does this cooking oil last? How to tell if this oil has gone bad? How to store canola oil? 

How to Tell if Canola Oil is Bad

Oil is a natural food preservative, hence, it is typically a long-lasting food item. However, proper storage is still required to maintain the quality and shelf life. 

Unlike perishable foods (like meat products) that are prone to bacterial contamination, canola oil is more susceptible to exposure to air, heat, and sunlight. As with other fatty or oily foods, canola oil is vulnerable from going rancid.

Due to its high unsaturated fatty acid content, long storage times or the widely-used long heating periods lead to changes in the free fatty acids level, formation of polymers, reduction in the unsaturation degree, changes in the peroxide value, chemical changes with off-flavor and rancid smell, changes in color, and reduction in nutritional value (4).

The smell is the first thing you need to check when observing the oil. Canola oil has a light flavour. If it smells rancid or unpleasant in any way, it’s time to discard it. 

Rancid oil will ruin the taste of your dishes. In addition, free radicals present in rancid oil can have negative effects on health. Body cellular components such as protein, lipid and nucleic acid are sensitive to free radicals from oxidation reactions. These free radicals have an important role in causing heart diseases, cancer and aging (4). Next, any notable changes in colour and texture or presence of molds is an alarming sign. Canola oil is generally clear and transparent. If it darkens, it shouldn’t be used for cooking.

3 Nutritional facts about canola oil

Contains Vitamins 

Canola oil contains vitamin E and K in a reasonable quantity. Vitamin K plays an important role in bone formation and blood clotting. It reduces the chances of serious injuries and excessive bleeding (6).

On the other hand, Vitamin E is a potential antioxidant that protects the body cells from the damage caused by free radicals. Free radicals are harmful substances released during metabolism and are neutralized by adequate vitamin and mineral consumption (4). 

Both Vitamin E and K are fat soluble vitamins that can be stored in the body. So, adequate consumption of canola oil helps build up reserves in the body. 

Contains Omega-3 and 6 fatty acids

Consumption of canola oil influences biological functions that affect various other biomarkers of disease risk. For the treatment of existing cardiovascular disease, canola oil has been recommended for achieving daily n-3 FA requirements of 1 g/day. Studies reveal substantial reductions in total cholesterol and low-density lipoprotein cholesterol, as well as other positive actions, including increased tocopherol levels and improved insulin sensitivity, when canola oil was consumed, compared with consumption of other dietary fat sources (5).

Best cooking oil

Despite being infamous for its overconsumption, canola oil has only 7% saturated fat, which makes it an ideal choice for sauteing and baking. The flavor of canola oil is also mild and does not interfere with the taste of other ingredients.

Summary

When stored well, canola oil can last for 1 year or more. What’s much more likely to happen

is that the oil goes rancid. Rancidity is caused by prolonged exposure to air, light, moisture,

or by bacterial action. Generally, rancid oil isn’t unsafe to consume, but it has that specific

rancid smell and taste. So if you notice that your oil is rancid, you can continue using it or

discard it.

Conclusion

In this brief guide, we addressed the question, “Does canola oil go bad”? as well as other questions pertaining to the subject at hand like how to store canola oil and how long it can last. 

References:

1. Carré, Patrick, and André Pouzet. Rapeseed market, worldwide and in Europe. Ocl, 2014, 21, D102.  
2. Wroniak, Małgorzata, and Agnieszka Rękas. Nutritional value of cold-pressed rapeseed oil during long term storage as influenced by the type of packaging material, exposure to light & oxygen and storage temperature. J food sci technol, 2016, 53, 1338-1347.  
3. Przybylski, Roman, et al. Canola oil. Bailey’s industrial oil and fat products, 2005, 2, 61-122.
4. nasiri Takami, Seyedeh Tahereh. The antioxidant effect of Mentha pulegium extracts on the stability of canola oil during storage conditions. J. Appl. Environ. Biol. Sci, 2015, 4, 112-117.
5. Lin, Lin, et al. Evidence of health benefits of canola oil. Nutr rev, 2013, 71, 370-385.
6. Ryan-Harshman, Milly, and Walid Aldoori. Bone health. New role for vitamin K?. Can Fam Phys, 2004, 50, 993-997.