All About Oils

Photography by Chris Cassidy

Visit the cooking oil aisle of your local grocery store to find many oils of nuts, seeds, fruits and vegetables — each with distinct flavors and properties that make them tasty additions to your cooking repertoire and healthful flavors for your dinner table.

When it comes to cooking, some oils can handle the heat better than others. “Smoke point” is the temperature at which oil starts to break down. Oils with high smoke points (such as vegetable, peanut and sesame) are good for frying or high-heat stir-frying, while oils with low smoke points (flaxseed or walnut) work well in salad dressings and dips. Discard cooking oil if it starts to smoke; it's lost some of its nutritional value and it could impart a bitter, unpleasant taste to food.

Heat and light damage most oils. Over time, these elements cause oil to degrade and lose some of its nutrients. Store oil in a cool, dark place and replace it if it smells bitter or “off.” Some oils — particularly polyunsaturated oils such as grapeseed or walnut oil — may turn rancid faster than other oils. Store these oils in the refrigerator to prolong their usability.

Plant oils are a rich source of monounsaturated and polyunsaturated fatty acids (MUFAs and PUFAs, respectively). When used in place of saturated fats, these heart-healthy fats may help reduce the risk of heart disease and stroke by improving related risk factors such as total and LDL blood cholesterol, blood pressure and inflammation. Plant oils also provide essential nutrients such as vitamin E to help build and maintain cells in the body.

Low in saturated fat and high in mono- and polyunsaturated fats, including omega-3s, canola oil has a light flavor that makes it a versatile ingredient. Replace solid fats such as butter or margarine with canola oil when cooking or baking. Canola oil works well for sautéing and stir-frying, and for coating pots, pans and the grill to prevent sticking.

With omega-6 and omega-9 essential fatty acids, heart-healthy flaxseed oil is often cited as a vegetarian alternative to fish oil. Flaxseed oil has a low smoke point, so it’s not ideal for cooking. Instead, enjoy a drizzle over quinoa or combine it with herbs and vinegar to make a salad dressing.

With an alluring green hue, a buttery, nutty flavor and a composition of more than 70-percent monounsaturated fat, avocado oil is a heart-nourishing choice. Thanks to its high smoke point, avocado oil is ideal for sautéing and frying fish or chicken, but it also is a beautiful finishing oil and a flavorful base for salad dressing.

Peanut oil is a common monounsaturated fat and contains vitamin E. This oil is often used in deep frying because of its high smoke point, while its distinctive flavor makes it shine in stir-fries and ginger dressing.

Made from dried and cold-pressed nuts, walnut oil has a high concentration of alpha-linolenic acid that partially converts to omega- 3s, which support heart health. Walnut oil doesn’t stand up to high heat, so its rich, nutty flavor is best used as a dressing or flavor enhancer rather than for cooking. Store this oil in the refrigerator.

Coconut oil is extracted from the fruit of mature coconuts and is a saturated fat. Virgin coconut oil is high in lauric acid, a medium-chain fatty acid. Preliminary studies show that this acid may have a neutral or beneficial effect on cholesterol levels. Coconut oil has a sweet flavor and is often substituted for shortening or butter in vegan recipes. It imparts a tropical flavor to vegetables, curry dishes and fish.

An all-purpose cooking oil with a mild flavor and aroma, corn oil is high in polyunsaturated fatty acids. Corn oil is ideal for baking, sautéing or stir-frying. Use it to create flavorful Southwestern soups, stews or quesadillas.

Sesame oil is rich in mono- and polyunsaturated fatty acids. Sesame oil is typically used in Asian cuisines and has a sweet, nutty flavor. Toasted sesame seed oil has a more intense flavor and aroma. Drizzle it over an Asian cabbage slaw with a sprinkle of black sesame seeds.

Pumpkin Seed
Pumpkin seed oil has a deep color and rich, nutty flavor. This oil delivers a heart-healthy boost from its linolenic acid content, although it’s not as plentiful as in walnut oil. Showcase this oil’s intensity with a drizzle over squash soup or create a flavorful salad dressing.

Extracted from grape seeds (a byproduct of wine-making), this oil is rich in polyunsaturated fatty acids, which lowers total cholesterol. Grapeseed oil has a moderately high smoke point, which makes it great for sautés and frying. It can also be used in dressings and dips for vegetables.

Often soybean oil or a blend of soybean and other oils, vegetable oil contains primarily polyunsaturated fats and considerable monounsaturated and saturated fat. With a neutral flavor and good heat tolerance, this all-purpose oil is best used in baking and sautéing.

While standard sunflower oils are high in polyunsaturated fatty acids (specifically linoleic acid), high-oleic versions are significantly higher in monounsaturated fats. Unrefined sunflower oil breaks down at high temperatures (use it for dressings or as a finishing oil). Refined sunflower oil has a higher smoke point and neutral flavor and color, making it ideal for high-heat cooking such as baking, frying or sautéing.

Olive oil is high in monounsaturated fatty acids, which may help reduce the risk of heart disease. Extra-virgin olive oil has less acid, a fruitier flavor and stronger aroma than pure or virgin olive oil. Olive oil labeled as “light” is often lighter in hue or flavor, but not lighter in calories. Use olive oil in dressings, sautés, cakes, for dipping and to fry vegetables and meat.

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Marisa Moore
Marisa Moore, MBA, RDN, LD, is based in Atlanta and specializes in culinary nutrition, communications and consulting. She blogs at Follow her on Instagram and Twitter.