Can sesame oil go bad?

In this brief guide, we are going to answer the question “can sesame oil go bad” with an in-depth analysis of whether or not sesame oil goes bad and the health implications of consuming rancid sesame oil. Moreover, we are going to discuss how long sesame oil can stay good and the proper storage tips for sesame oil.

So without much ado, let’s dive in and figure out more about it.

Can sesame oil go bad?

Yes, sesame oil can go bad as it has the ability to go rancid after a certain time. Not only a sesame oil that has gone bad will have a rancid odor and taste but it can also cause serious health implications when it is consumed in large quantities over a long period of time (7). Sesame oil is an unsaturated oil and 80% of its fatty acids are unsaturated. Sesame oil is rich in vitamin E and its free fatty acid content is relatively low. This oil is highly rancid under oxidation conditions and gives a bad smell (2).

The rancid smell is a musty smell that is unpleasant and quite noticeable. Moreover, if you feel some unpleasant taste or rancid taste while taking a bite of food fried in sesame oil then it means that your oil has gone rancid and it is better to discard it.

It is possible for vegetable oils to go rancid and lose their nutritional value and flavour if they are handled or stored incorrectly. Sunlight and antioxidants, as well as moisture, all contribute to the oils’ rancidity (7).

Sesame production has been recorded in the Middle East and India since 4000 years ago. About 60% of the world’s sesame production was from Myanmar, India, China, Ethiopia and Nigeria during 2011 (1).

What are the health implications of consuming rancid oil?

The excessive consumption of rancid oil has been seen associated with free radicals production in the body that can cause certain harmful effects. The rancid oil has carcinogenic free radicals in it and if someone consumes such oil in large quantities then these free radicals will mess up the normal body functioning. 

Continuous usage of the same vegetable oil which is not even properly stored and re-using the already fried oil (rancid) lead to generation of free radicals through lipid peroxidation. Oxidation is a chemical reaction that transfers electrons from a substance to an oxidizing agent. Oxidation reactions can produce free radicals, which start chain reactions that damage cells (8). Short-term usage of rancid oil won’t cause any significant health issues but if you consume rancid oil over a long period of time then it can result in an increase in the number of free radicals in the body that can in turn damage the cells of the body, proteins, and DNA.

You can read about the effect of free radicals on the body here.

Is it safe to use sesame oil after the “best by” or “best before” date?

The “best by” or “best before” date that is written on the bottle of sesame oil refers to the quality rather than safety so sesame oil doesn’t necessarily go bad immediately after the best before date (6). It is the time during which you can enjoy the peak quality and flavor of sesame oil but you can still use sesame oil that is past this date as long as it was stored properly.

Together with extrinsic factors coming from the packaging and the environment, the oil’s compositional aspects primarily influence its shelf life, giving it more or less sensitivity to light, O2, temperature, enzymes, and all the potential causes of shelf life reduction (3). The higher degree of unsaturation in the oils accelerates the oxidation process in oils and fats. Therefore, as a result of oil oxidation, the aldehydes, ketones, and short-chain fatty acids are created, which cause an unpleasant odor in oil (2).

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What is the shelf life of sesame oil?

When it comes to the sesame oil, unopened sesame oil lasts for about 18 months or even more if it is stored in a cool, dry, and dark corner of your pantry away from direct sunlight and heat. It is the time during which you can enjoy the best quality of the sesame oil which means that you can still use properly stored sesame oil even after this time. According to the USDA, sesame oil has a shelf life of 2 years when kept unopened and stored at room temperature. After opening, the shelf life is reduced to 6 months (4).

Moreover, opened sesame oil lasts for about 6 months if it is stored in a cool, dry, and dark corner of the pantry away from direct sunlight and heat. Moreover, refrigeration can increase the shelf life of the sesame oil and sesame oil lasts for about 1 year when it is properly stored in the fridge at or below 40 degrees Fahrenheit. You should keep in view that refrigerated sesame oil can become cloudy and can even solidify. The storage at low temperatures may reduce the oxidation reactions, limiting the loss of antioxidants and extending the shelf life of oils (5).

It is worth mentioning that these figures are just the estimated shelf life of sesame oil and sesame oil can even last for more than this, provided that it was stored properly. 

Storage tips for sesame oil

  1. You should store your sesame oil away from direct sunlight and heat. As sunlight and heat can increase the rate at which sesame oil can go rancid or stale (5).
  2. You can store the unopened sesame oil easily in a cool, dry, and dark corner away from direct sunlight and heat. Thus you can store sesame oil in your pantry or kitchen cabinet. You can store the sesame oil in the pantry even after it has been opened and it can last for a long time there (9). 
  3. Moreover, you can also refrigerate your sesame oil to prolong its shelf life (5).
  4. You should close the lid of the bottle containing sesame oil as soon as you have poured the oil that you need so that it will minimize air or obnoxious agent exposure of your sesame oil.

Conclusion

In this brief guide, we answered the question “can sesame oil go bad” with an in-depth analysis of whether or not sesame oil goes bad and the health implications of consuming rancid sesame oil. Moreover, we discussed how long sesame oil can stay good and the proper storage tips for sesame oil.

Citations

  1. Ayana, Negash Geleta. Status of production and marketing of Ethiopian sesame seeds (Sesamum indicum L.): A review. Agric Biol Sci J, 2015, 1, 217-223.
  2. Chavoshizadeh, Sona, Sajad Pirsa, and Forough Mohtarami. Sesame oil oxidation control by active and smart packaging system using wheat gluten/chlorophyll film to increase shelf life and detecting expiration date. Euro J Lipid Sci Technol, 2020, 122, 1900385.  
  3. Piergiovanni, Luciano, and Sara Limbo. Packaging and the Shelf Life of Vegetable Oils. Food packaging and shelf life. 2010, 317. 
  4. FoodKeeper. United States Department of Agriculture.
  5. Mousavi, Soraya, et al. Evolution of Extra Virgin Olive Oil Quality under Different Storage Conditions. Foods, 2021, 10, 2021.
  6. Gravely, M. Before you toss food, wait. Check it out!. United States Department of Agriculture. 2022. 
  7. Singh, Mukesh Kr, et al. Effects of Repeated Deep Frying on Refractive Index and Peroxide Value of Selected Vegetable Oils. Int J Res Appl Sci Biotechnol, 2022, 9, 28-31.
  8. Borjian Borojeni, M., A. Goli, and M. Gharachourloo. Effect of roasted sesame oil on qualitative properties of frying oil during deep-fat frying. J Agric Sci Technol, 2016, 18, 1531-1542. 
  9. McCurdy, Sandra M., Joey D. Peutz, and Grace Wittman. Storing food for safety and quality. 2009.