Category: Nutrition

Cooking Oil 101: The Basics

The cooking oil display in the grocery store is overwhelming. There are so many options, and there are variations of each type of oil. Attune Health nutritionist and research associate Natalie Fortune breaks down the basics of healthy cooking with oil and the best way to store it.  

 

TYPES OF OILS

Polyunsaturated fats are liquid at room temperature and generally the least stable for cooking. They are found in safflower and sunflower oils, and oxidize easily if not specifically labeled for high heat or “high oleic.”

Monounsaturated fats also are liquid at room temperature and found in canola, nuts and olives. They are generally are more stable than polyunsaturated fats.

Saturated fats are solid at room temperature and very stable. Think butter and ghee. They resist oxidation, so they often can tolerate higher temperatures. These, however, are not heart healthy choices.

 

COOKING TEMPERATURE

Some fats and oils do better than others when cooking over high temperatures, while some are better suited for low or no heat.

Each cooking oil has a smoke point: the temperature at which the oil will burn and become damaged, potentially creating cancer-causing properties to form . If oil smokes in the pan, discard it. The temperature is too high. Clean the pan and start over at a lower temperature.

Smoke points for a fat or oil can vary depending on the quality and variety of the source ingredients, and on whether the fat or oil has been refined.

Good high-heat cooking oils include: avocado oil, refined coconut oil, refined grapeseed oil and refined safflower oil.

Healthy low-heat oils include: olive oil, macadamia nut oil, sesame oil and walnut oil. These oils are great for dressings and finishing dishes.

 

OIL CATEGORIES

Unrefined oils are filtered only lightly to remove large particles. Some, such as sesame or olive oil, may appear cloudy or have visible sediment after sitting. This does not compromise quality. Unrefined oils have more pronounced flavors, colors and fragrances than refined oils, and are more nutritious with a shorter storage life than refined. These oils retain all the minerals, enzymes, vitamins and phytonutrients of the source ingredient.  Virgin and extra-virgin oils fall under this category. Unrefined oils are best used unheated in dressings or with low heat. Their natural resins and other beneficial particles burn easily and develop unpleasant flavors and unhealthy properties if overheated.

Extra-virgin oils are generally from the first pressing of the source ingredient. These oils can be fragile, so they should be reserved for dressing, drizzling and dipping. Note that olive oils must meet specific requirements for acidity in order to be labeled as “extra-virgin.”

Virgin oils are generally from the second pressing of the source ingredient. These oils are also fragile and should be reserved for low-heat cooking, dressing and drizzling. Virgin oils must pass standards for taste and quality, but the standards are not as rigid as those for the “extra-virgin” qualification.

Cold-pressed oils are extracted from their source using pressure only. This process is used to create the virgin and extra-virgin oils. Chemicals and heat are not used in this process. This helps the oils retain all of the nutritional benefits of the source ingredient.

Naturally refined oils are more thoroughly filtered and strained than unrefined, usually with some additional heat but without harsh or damaging chemicals. Refining reduces the nutrient level and flavor. It also removes particles and resins and makes naturally refined oils more stable for longer storage, more resistant to smoking and a good choice for high-heat cooking and frying.

Oils like canola, grapeseed, vegetable shortening and corn oil have high smoke points and seem safe for cooking, but these fats and oils undergo heavy processing. These processing methods counteract any potential health benefits. These fats and oils are also high in omega-6 fatty acids, which can cause chronic inflammation in the body. Because of this, regularly consuming fats and oils from this list is not recommended. If you do consume these fats and oils, be sure to choose brands that are certified organic and made from non-GMO crops.

 

STORING AND BUYING OILS

Oils should be stored in air, heat and light safe containers because these can cause oils to oxidize and turn rancid, which studies suggest may promote cancer and heart disease. For maintaining quality of flavor and nutrition, it is best to store oils in an airtight glass bottle in a cool, dark place. For oils that will sit unused for longer than one month, store in the refrigerator.

 

COOKING OIL DOs AND DON’Ts

Do:

  • Purchase oils in dark glass bottles and packaged in containers with tight-fitting lid or seal
  • Store your oils in a dark, cool place

Don’t:

  • Purchase oils in plastic containers, or containers with a loose-fitting lid.
  • Store your oils next to the stove or heat source, or in a place with artificial or natural light