Coconut oil has become increasingly popular in recent years for cooking, cosmetic, and medicinal purposes. It is prized for its high concentration of medium chain triglycerides (MCTs) like lauric acid, which provide numerous health benefits. However, there are different types of coconut oil on the market. While virgin and extra virgin coconut oil are cold-pressed from fresh coconut meat, fractionated coconut oil undergoes a distillation process to isolate the MCTs. This raises the question: since fractionated coconut oil is processed differently, will it go rancid like other oils?
In short: Yes, fractionated coconut oil can go rancid, but it has a much longer shelf life than virgin coconut oil. The distillation process removes most of the long chain fatty acids while concentrating the medium chain fatty acids, giving fractionated coconut oil a higher resistance to oxidation and rancidity. With proper storage, fractionated coconut oil can last up to 2 years before going bad. Virgin coconut oil, on the other hand, has a shelf life of about 18 months.
To understand why, let’s take a closer look at how oils go rancid and the composition of fractionated coconut oil.
How Do Oils Go Rancid?
Oils go rancid through oxidation, which happens when oils are exposed to oxygen, light, or heat. Oxidation causes free radicals to form, leading to chain reactions that degrade the quality of the oil. When oils oxidize, they break down and release volatile organic compounds that give rancid oil its unpleasant aroma and taste.
The main factor that determines an oil’s resistance to oxidation is its fatty acid profile. Oils high in polyunsaturated fatty acids (PUFAs) are most susceptible to going rancid, while oils high in saturated and monounsaturated fatty acids have greater stability.
Coconut oil is over 90% saturated, making it very slow to oxidize compared to oils like canola or sunflower that have high PUFA content. However, virgin coconut oil contains small amounts of PUFAs that make it more prone to rancidity than fractionated coconut oil.
Composition of Fractionated Coconut Oil
During fractionation, coconut oil is heated to just below its boiling point. The high heat vaporizes the light and volatile short chain fatty acids, separating them from the medium and long chain fatty acids.
The medium chain fatty acids like caprylic (C8) and capric acid (C10) have lower boiling points, so they are able to vaporize while leaving behind the long chain fatty acids like lauric (C12), myristic (C14), and palmitic (C16) acids. After vaporization, the medium chain fatty acids are cooled and condensed back into liquid form – resulting in an oil with a high concentration of MCTs.
Typical composition profiles for fractionated vs. virgin coconut oil:
| Fatty Acid | Fractionated Coconut Oil | Virgin Coconut Oil |
|---|---|---|
| Caprylic Acid (C8) | 60% | 7% |
| Capric Acid (C10) | 30% | 6% |
| Lauric Acid (C12) | 5-10% | 49% |
| Myristic Acid (C14) | <5% | 16% |
| Palmitic Acid (C16) | <2% | 9% |
| Oleic Acid (C18:1) | <2% | 6% |
| Linoleic Acid (C18:2) | <1% | 2% |
As you can see, fractionated coconut oil contains very little of the long chain saturated fats and PUFAs that are most prone to oxidation. By removing these fragile fatty acids, fractionated coconut oil gains a longer shelf life.
How Long Does Fractionated Coconut Oil Last?
The concentrated medium chain fatty acids in fractionated coconut oil give it an impressive resistance to rancidity. With proper storage, fractionated coconut oil can remain fresh for up to 2 years past its manufacturing date.
However, that lengthy shelf life depends on ideal storage conditions:
- Store in an airtight container to limit air exposure
- Keep in a cool, dark place away from heat and light
- Refrigerate after opening to further slow oxidation
If fractionated coconut oil is left at room temperature, exposed to air and light, it may only last 6-12 months before going rancid. Refrigeration and full containers help prevent oxidation.
In comparison, virgin coconut oil lasts about 18 months with typical kitchen storage. It contains more unstable PUFAs and lacks the antioxidant properties of unrefined coconut oil that help counter rancidity. Fractionation gives the oil better stability.
How to Tell If Fractionated Coconut Oil Has Gone Rancid
Watch for these signs that your fractionated coconut oil has gone bad:
- Change in color: Fresh fractionated coconut oil is clear and colorless. It may turn yellow or orange as it oxidizes.
- Change in smell: Rancid fractionated coconut oil smells off, with a paint-like or unpleasant aroma.
- Change in taste: The oil will taste bland or soapy rather than having a mild coconut flavor.
- Change in texture: Separated oil layers or inconsistent texture indicates spoilage.
- Formation of foam: Bubbles or foaming when shaken signals the oil has gone rancid.
If your fractionated coconut oil shows any of these warning signs, it has likely oxidized too much and should be discarded.
How to Prevent Fractionated Coconut Oil From Going Rancid
Here are some tips for keeping fractionated coconut oil fresh for as long as possible:
- Purchase small containers to limit air exposure each time you open the bottle.
- Store in a cool, dark place like a pantry or cupboard away from heat sources.
- Transfer to an air-tight container or jar after opening.
- Keep away from light by storing in an opaque container or covering with aluminum foil.
- Refrigerate after opening – cold temperatures slow oxidation.
- Use a clean, dry spoon to remove oil – moisture can introduce bacteria.
- Don’t transfer back and forth between containers.
- Check the manufacturing date and write the purchase date on the bottle.
- Use within 1-2 years of purchase for best quality.
Following these precautions can help your fractionated coconut oil stay fresh and pristine for up to 2 years.
Does Fractionated Coconut Oil Need Refrigeration?
Refrigeration isn’t strictly necessary, but can dramatically slow the oxidation process and extend the shelf life of fractionated coconut oil. Storing in the fridge after opening is recommended for keeping it fresh as long as possible.
The bottom line is fractionated coconut oil remains liquid at typical refrigerator temperatures. Some people prefer to store it in the pantry since it won’t solidify like virgin coconut oil. But easy liquidity comes at the cost of faster spoilage.
Here are the ideal storage temperatures for fractionated coconut oil:
- Unopened: 68-76°F (20-24°C)
- Opened: 32-50°F (0-10°C)
You can keep an unopened bottle in the pantry, but move it to the refrigerator after opening for maximum longevity. The cool environment dramatically slows oxidation.
Does Fractionated Coconut Oil Go Bad?
Yes, fractionated coconut oil can eventually go bad once it has oxidized and become rancid. Signs it has spoiled:
- Change in color, smell, taste
- Separation, inconsistent texture
- Foaming or bubbling when shaken
- Mold growth, if bacteria entered the container
At room temperature, fractionated coconut oil may start to go rancid 6-12 months after opening. In the refrigerator, it can last 1-2 years past its manufacturing date before oxidizing too much.
If your fractionated coconut oil shows any signs of spoilage, it has gone bad and should not be consumed. Discard the rancid oil.
Can You Restore Rancid Fractionated Coconut Oil?
Unfortunately, once fractionated coconut oil has gone rancid, there is no way to restore it to an edible state. The chemical changes from oxidation cannot be reversed.
Attempting to deodorize rancid oil through charcoal filtering or chemical processing will not remove the free radicals that make it unfit for consumption. Rancid oil’s negative health effects include:
- Digestive upset
- Damage to arteries and LDL cholesterol
- Chronic inflammation
- Joint pain
For these reasons, rancid fractionated coconut oil is best discarded. Don’t take any risks with spoiled oil.
The Shelf Life of Other Types of Coconut Oil
Besides fractionated coconut oil, there are two other main varieties – virgin and refined:
Virgin coconut oil: Unrefined, extracted from fresh coconut meat. Has a coconut aroma and flavor. Shelf life is 1-2 years.
Refined coconut oil: Chemically processed with bleaching and deodorizing. Neutral scent and taste. Lasts 2-3 years.
Fractionated coconut oil: Distilled to isolate MCTs, making it very stable. Shelf life of 2+ years.
Virgin coconut oil goes rancid fastest since it is unprocessed and contains delicate PUFAs. Refined and fractionated oils last longer due to processing that improves stability.
The Shelf Life of Other Oils
Here’s how the shelf life of fractionated coconut oil compares to other common cooking oils:
| Oil Type | Shelf Life |
|---|---|
| Extra virgin olive oil | 6-12 months |
| Avocado oil | 6-12 months |
| Walnut oil | 3-6 months |
| Flaxseed oil | 4-6 months |
| Virgin coconut oil | 12-18 months |
| Fractionated coconut oil | 18-24 months |
| Refined coconut oil | 24-36 months |
| Sunflower oil | 12-24 months |
| Vegetable oil | 6-12 months |
| Peanut oil | 12-24 months |
Oils high in polyunsaturated fats like walnut and flaxseed oil go rancid fastest. Monounsaturated oils like olive and avocado oil also oxidize quickly. Fractionated coconut oil lasts significantly longer than other premium oils thanks to its high saturated fat content.
Frequently Asked Questions
Does fractionated coconut oil need to be refrigerated after opening?
Refrigeration after opening is recommended to extend the shelf life, but not strictly required. Store fractionated coconut oil in an air-tight container in a cool, dark place for 1-2 years of freshness without refrigeration.
What is the best temperature to store fractionated coconut oil?
Unopened fractionated coconut oil can be stored at room temperature from 68-76°F (20-24°C). After opening, it’s best kept refrigerated between 32-50°F (0-10°C) to slow oxidation.
How long does fractionated coconut oil last compared to virgin coconut oil?
Fractionated coconut oil lasts about 2 years from the manufacturing date when stored properly. Virgin coconut oil lasts about 1-1.5 years before going rancid since it contains more fragile fatty acids.
Why does fractionated coconut oil last so long compared to other oils?
The long shelf life of fractionated coconut oil stems from its high concentration of saturated medium chain fatty acids like lauric acid. These MCTs resist oxidation far better than the polyunsaturated fats found in many other oils.
Is it safe to use fractionated coconut oil that smells or looks weird?
No, changes in the appearance, smell, texture, or taste likely mean the oil has gone rancid and should not be consumed. Oxidized oil contains unhealthy compounds and free radicals that can negatively impact health.
The Bottom Line
While fractionated coconut oil has excellent stability compared to other oils, it can eventually go rancid like any fat. Storing it properly in a cool, dark place in an air-tight container can prolong its shelf life to about 2 years. Refrigerating after opening is ideal for maximizing freshness.
Check fractionated coconut oil that is past its prime for any signs of spoilage like color changes, odor, inconsistent texture, or foaming. Rancid oil should be discarded, as oxidation causes the development of toxic free radicals and off-flavors that make it unfit for consumption.
