One of the more notable changes in the American diet during the last century has been a shift in the types of oils used for cooking. For centuries, most people relied on butter, margarine or shortening for cooking. Less than a decade ago, the vegetable oils on grocery store shelves were derived from
either corn or soybean. However, as consumers began to understand how fat intake affects overall health, food manufacturers started to produce oils that were lower in saturated fats and higher in mono- and polyunsaturated fats, such as canola, olive and safflower oils.

Today, new and unusual nut, seed and vegetable oils are
appearing in the marketplace,
offering consumers a wide variety of culinary choices. Consumer
interest in complementary and alternative medicine has also led to the use of so-called “therapeutic” or “essential” oils, touted for their nutritional benefits and potential healing properties. These products, once found solely in health food stores, are now available in many mainstream grocery stores.

Like the more familiar cooking oils, these new nontraditional oils are not created equally; they vary tremendously in terms of flavor, composition and nutritional quality. The following sections highlight the unique properties of some of the new oils, along with their best uses in cooking and food preparation.

Opting for the Right Oil

Anyone who has ever stood over a hot stove wondering why a skillet full of sputtering oil has sent the smoke detector into overdrive has learned a valuable lesson: the oil that worked so well as a salad dressing may be a disaster when used to fry chicken.

When preparing to use an unfamiliar oil in a recipe, consider the following:

  • Does the color, aroma and consistency of the oil complement the dish being prepared?
  • Will the oil be used to deep-fry or sauté a food, or be used cold as a marinade or dressing?

A simple rule of thumb when choosing a cooking oil is that oils high in polyunsaturated fatty acids are volatile and poorly suited to cooking foods at high temperatures; conversely, oils rich in monounsaturated fat are more stable and may be used at high temperatures with good results. The exception to this general rule is olive oil, which is high in monounsaturated fat but tends to be unstable when exposed to high temperatures.

It is also important to know the smoke point of a cooking oil. The smoke point refers to the temperature at which an oil begins to burn and break down. Oils with high smoke points (greater than 350 degrees Fahrenheit or 175 degrees Celsius) are generally the most stable and the best suited for high-heat cooking. In addition, refined or semirefined oils tend to have higher smoke points than unrefined varieties. (For a look at the smoke points of popular cooking oils, see the sidebar “Salad or Stir-Fry: How to Use New Cooking Oils.” )

Take care to store all vegetable oils in the proper location and at the right temperature. Most cooking oils keep best when refrigerated or when stored in a cool, dark place. Oils with a percentage of polyunsaturated fat (e.g., pumpkin seed, walnut and grapeseed oils) have a shelf
life of about 6 months, whereas monounsaturated oils (e.g., avocado, rice bran, macadamia and hazelnut oils) will keep for a year if properly stored. Be sure to read labels for specific storage instructions.

Avocado Oil

Since its introduction in 1999, avocado oil has become popular with chefs around the world. It has one of the highest smoke points (520°F) of all the plant oils, making it very well suited to many types of cooking and food preparation. Like olive oil, it is rich in monounsaturated fat, and it is also an excellent source of vitamin E. Avocado oil retains the delicate scent and pale green color of the fruit, making it a lovely accent in food preparation.

Grapeseed Oil

Derived from the seeds of wine grapes, grapeseed oil is very well suited to a
variety of cooking methods. Despite being rich in polyunsaturated fat, it has a very high smoke point (around 420°F). In addition, grapeseed oil is a natural source of vitamin E and contains traces of certain plant pigments believed to protect against disease. Because of its stability, neutral flavor/aroma and long shelf life (1 year), restaurants often use grapeseed oil for high-heat cookery. It is also ideal for salad dressings and for preparing infusions of strongly flavored herbs and spices.

Macadamia Nut Oil

Like avocado and grapeseed oils, macadamia oil is well suited for cooking at high temperatures. It is very high in monounsaturated fat (80%–85%) and has a high smoke point (413°F) and a long shelf life (1–2 years). Plus, its creamy flavor and golden color make it a good choice for salad dressings, marinades and sauces. Macadamia oil is especially prized by bakers for the velvety texture it imparts to pastries, cakes and cookies.

Hazelnut Oil

This oil is made from cold-pressed hazelnuts and can be used for cooking and baking or for salad dressings and sauces. A monounsaturated fat, it has a high smoke point of (430°F). However, because of its strong flavor, hazelnut oil is typically used sparingly or blended with other oils. One of its best uses is in chocolate baked goods and desserts, which are enhanced by its characteristic nutty flavor.

Pumpkin Seed Oil

Extracted from the roasted, hulled seeds of the pumpkin, this oil is thick and brilliantly colored (ranging from red to yellow and green). However, like most oils rich in polyunsaturated fats, pumpkin seed oil is not stable when heated (its smoke point is 320°F or lower), and thus it is not often used in cooking. Instead, it has found a niche as an ingredient in salad dressings, spreads and marinades. Pumpkin seeds are an excellent source of plant sterols, vitamin E, beta carotene and zinc, so these same compounds may also be present to varying degrees in the oil itself, depending on processing, storage, etc. In Eastern Europe, pumpkin seed oil is a popular remedy for a variety of disorders, including enlarged prostate, elevated cholesterol and irritable bowel syndrome.

Rice Bran Oil

Rice bran oil is produced by grinding the bran component of the rice kernel. The resultant oil is made up predominantly of monounsaturated fat. Rice bran oil is a rich source of both vitamin E and vitamin K, and it also contains a powerful plant sterol believed to lower cholesterol, relieve digestive upset and reduce menopausal symptoms.

Due to its extremely high smoke point (490°F), it can be successfully used in deep-frying and stir-frying, which may be why it is the oil of choice in many Asian restaurants. Light in texture, rice bran oil enhances flavor and prevents foods from tasting greasy.

Walnut Oil

Walnut oil has a delicate, nutty flavor and a lovely amber color. That said, it is not widely used in cooking, since it turns bitter when heated (the heat also destroys its antioxidants). In addition, the walnuts must first be roasted, and the resulting oil is then pressed and filtered, which is why it is relatively expensive compared with other oils. As a result, walnut oil is most often used unheated in dressings, marinades and cold sauces. Like pumpkin oil, it has a low smoke point (320°F or lower).

A Salve for Cooks

As food producers continue to explore healthy alternatives to dietary fats, consumers can expect to see an increasing number and variety of new cooking and therapeutic oils in the marketplace. Whether added to salads or used in baking, these nontraditional oils add zest and flavor, and may provide a perfect complement to a healthy lifestyle