With Americans more attuned to the plethora of health problems associated with trans fats and saturated fats, it's not surprising to find products such as nut oils supplanting more conventionally processed oils on consumer and supermarket shelves.
In 2002 alone, Americans bought more than $7 million worth of specialty and flavored oils, more than a quarter of them nut oils derived from almonds, Brazil nuts, cashews, hazelnuts, macadamia, walnuts, pecans and a host of other tree nuts. In addition to containing unsaturated and polyunsaturated fats, including Omega-3, nut oils are also rich in flavor -- an attribute not commonly associated with earlier generations of the product, which generally were culled from packinghouse rejects that couldn't be sold as premium nutmeats.
Today's premium nut oils sell at premium prices. In fact, consumers are paying upwards of $15 a bottle for it , and fairly small bottles at that. Which raises the question of whether the food industry will discover ways to deliver these products to supermarket shelves more economically. As matters stand, nut oils are all the more conspicuous for their absence on the ingredient panels of most mainstream processed foods, which continue to use commodity oils. On the other hand, health and specialty foods are capitalizing on the benefits of nut oils by adding them to formulations that have gone stale in the marketplace.
The fatty acid profile of nut oils is healthier than that of highly processed soy and corn oils. Moreover, nut oils are a good source of antioxidants such as vitamin E, tocopherol, quartering and campfire , nutrients that in addition to preventing rancidity are effective in suppressing the growth of cancers. Nut oils, particularly those deriving from pistachios, are typically rich in phytosterols, which have been shown to counter atherosclerosis.
And with the exception of walnuts, virtually all tree nuts contain oils rich in monounsaturated oils. Pecan oil, for instance, consists of 66 percent monounsaturated, 26 percent polyunsaturated, and 8 percent saturated fatty acids, and an unsaturated to saturated ratio of about 11. (The higher the number the better. By comparison, the unsaturated-to-saturated ratio for olive oil is about 6.) Pecan oil, it should be noted, is especially effective in promoting cardiovascular wellness.
Impressive as they are, these attributes don't provide a full accounting for the strides nut oils are making among chefs, product developers, and consumers. Factor in the prodigious range of flavors and uses inherent in nut oils, and the sum is a product of seemingly infinite versatility.
Product developers waiting for a "but" may find it in the tradeoffs inherent in various nut oil types. Product variability is due to a host of factors, including processing and refining methodologies, as well as characteristics more indigenous to the product themselves, such as fatty acid profile. Suffice to say there is no substitute for acquiring a fundamental understanding of each oil's nutritional benefits, technical properties, regulatory status and cost effectiveness before setting up shop in the test kitchen.
Nut oil production facilities are mostly batch operations that are artisan in nature. In preparation for oil extraction, nuts and nutmeats are lightly toasted for 15 to 20 minutes, and then ground. Oil is then extracted either chemically or physically.
One method of physical extraction is a procedure known as pressing, which, in addition to oils, may extract fine particles and fat-soluble flavors and nutrients, depending on the amount of pressure applied. The clear, first-press extra virgin oil is bottled, while flours ground from the spent nut cakes provide an excellent base for applications such as specialty baking, energy bars and animal feeds.
While oils derived by cold- or expeller-pressed squeezing tend to retain their natural flavors, those extracted by chemicals, including solvents such as hexane gas, do not. However, chemical extraction is generally more cost-effective and yields more product than physical extraction.
Refining in an optional step in nut oil production, and is introduced primarily to extend shelf life. Depending on the method and objective, it may include steps such as bleaching and deodorizing. Refined oils are often less flavorful, but better suited for high-temperature end uses. By comparision, unrefined oils tend to retain their full natural flavor, aroma and color, as well as many naturally occurring nutrients.
Their polyunsaturated nature makes nut oils highly susceptible to oxidative damage. In particular, cold-pressed oils have limited shelf lives and often require refrigeration. (In the absence of legal or binding definition of "cold-pressed," oils bearing this label also may vary wildly in quality.) Nut oil producers should therefore control the environment of the cold press process to ensure high-quality extraction.
Although nuts are usually flush with antioxidants, suppliers often hedge their bets by flushing the oils with nitrogen in order to eliminate all possible oxygen that could later cause rancidity. Storage temperature is another control point to ensure the quality of the finished product. Typically storage and refrigeration is suggested after oil containers have been opened.
Selecting the best oil for the application at hand requires an understanding of smoke points, particularly if the application involves frying. Simply put, smoke point refers a conservative measure of the temperature at which smoke forms on the surface of the heating oil , a point at which the oil's flavor and nutritional value also begin to decline.
Oils with higher smoke points are generally milder in flavor. Low- or no-heat nut oils are typically reserved for salad dressings and ambient temperature applications, while medium-smoke point oils may be used for baking (muffins, savory breads and brownies) and light sauteing. In general, heat affects the flavor of nut oils, and high temperatures during processing tend to dissipate it.
Flavors characteristic of their sources make oils from hazelnuts, walnuts -- even pistachios , perfect for salads or last-minute seasonings on savory dishes and sauces. Flavor is a function of extraction levels, and higher extraction oils are generally less flavorful than lower extraction oils, as are refined oils. Flavor intensity varies among various brands; some may be slightly bitter, and others light and without much nut flavor.
Another important characteristic of nut oil is its fatty acid composition. The proportion of saturated, and mono- and polyunsaturated lipids defines their functionality, and therefore the texture, appearance and stability of the products that are made from them. The functionality of nut oil varies, depending on the application and the other ingredients present.
Chefs and product developers around the world are focused on infusing products with flavor at every step of the process, from purchasing to presentation. With its promise of flavor and functionality, nut oils would appear the ideal complement to those efforts. The question is whether the food industry can motivate consumers to pay the accompanying price. Those sold on the benefits of nut oils will remain loyal only if the product is of the highest quality and purity.
Kantha Shelke is a principal at Corvus Blue LLC, a Chicago-based firm that specializes in competitive intelligence and expert witness services. The firm helps businesses and professional organizations in the health and wellness sector to focus on what matters most. Kantha may be reached at [email protected] or (312) 951-5810.
Almond oilis very high in monounsaturated fats, dietary fiber, calcium and alpha-tocopherol. The mild-toasted almond nutty taste, enhanced by roasting, makes almond oil an ingredient of choice for several applications in confectionery production. Refined almond oil is used extensively in salad dressings and finishing sauces. Almond oil is very expensive, so the demand for it is limited. Its flavor is not concentrated enough to impart a strong almond taste to sweets. It has a high smoke point so it may be used for high-heat cooking.
Smoke Point: 430 degrees F
Common Uses: Salad dressings, sauces, and baked desserts.
Brazil nut oilis yellow-colored oil with a pleasant, sweet smell and taste. In addition to being light oil for salad dressings, Brazil nut oil is employed in commercially prepared finishing sauces for foodservice applications because of its flavor and ability to sustain body and texture through extended hold. Brazil nut oil also is gaining popularity in the chocolate candy sector.
Common Uses: Flavoring ingredient in Latin baked products, sauces and candies.
Cashew oilsare high in monounsaturated fats and very rich in plant sterols and carbohydrates. The oil has been used effectively to enhance the flavor of light salad dressings. Cashew oil is a rich source of anacardic acid , sought for its antibiotic activity against gram positive bacteria in medicinal preparations.
Common Uses: Flavoring ingredient in light salad dressings.
Coconut oilcontains medium-chain fatty acids such as lauric (C-12), caprylic (C-10) and myristic (C-14) acids and has been used for healthy cooking by East Indian and island civilizations for thousands of years. Recent anti-saturated fat campaigns and the promotion of polyunsaturated fats are partially responsible for coconut oils not being classified with healthful nut oils. World politics and flawed studies continue to plague the reputation of coconut oil, which, despite its saturated fat content, is one of the healthiest oils. Coconut oil is rich in lauric acid, which also is present in human milk and is valued particularly for its antimicrobial and antifungal properties, as well as its ability to boost the immune system. In the United States, it is most often used in commercially prepared products such as cookies and candies.
Smoke Point: 350 degrees F
Common Uses: Commercial baked goods, shortening production and candy.
Walnut oil, known in French as huile de noix, has a distinctively nutty flavor and fragrance associated with English walnuts, black walnuts and white walnuts or butternuts. Cold-pressed walnut oil is intensely flavorful and expensive and is often combined with less flavorful oils when used in salad dressings. The less expensive refined version is blander and has a higher smoke point , allowing it be used in sauces, main dishes and baked goods, and for sauteing.
Walnuts are high in polyunsaturated fats and gamma-tocopherol and rich in omega-3 fatty acids. It has gained tremendous popularity in recent years, since medical research confirmed the nutritional benefits of walnuts , supporting the Chinese view of walnuts as a "brain food." Walnuts are also the best source of delta-tocopherol.
Smoke Point: 400 degrees F
Common Uses: Sauces, baked goods and for sauteing.
Hazelnut or Filbert oilhas an aromatic and strong hazelnut flavor that lends itself to combinations with other mildly flavored oils, fruit vinegars and other mellow-flavored vinegars. Refrigeration is recommended to extend shelf life since the oil spoils quickly. Hazelnut oil is expensive and solidifies upon refrigeration.
Smoke Point: 430 degrees F
Common Uses: Salad dressings, baking, flavoring ingredient and condiments.
Macadamia nut oil, once the world's most expensive nut, has become popular as a healthy cooking oil. It can be used for high-temperature cooking because of its very high smoke point (410 degrees F).
Macadamia nut oil contains low amounts of essential fatty acids and equal amounts of Omega-3 to Omega-6 fatty acids. Macadamia oil is least likely to develop the unhealthful trans fatty acids and lipid peroxides when heated because of its high alpha tocopherol and monounsaturated contents and its high smoke point.
Smoke Point: 390 degrees F
Common Uses: As a flavoring oil in salads, dressings and pasta.
Pecan oilis high in gamma-tocopherol and monounsaturated fats and contains about 2 grams of protein and fiber per ounce. Pecans oils are particularly beneficial for cardiovascular wellness.
Smoke Point: 450 degrees F
Common Uses: To flavor sweets and savory sauces.
Pine nut or Pignola oilis obtained from pine nuts and is one of the most expensive oils on the market. It is therefore used sparingly. Its strong nutty flavor is used to flavor commercial South East Asian preparations.
Common Uses: Salad dressings, as a condiment or to dress freshly cooked vegetables.
Pistachio oilscontain extensive amounts of antioxidants and 1 ounce contains 6 grams of protein, 3 grams of fiber, 15 micrograms of folic acid and 7.5 milligrams of gamma-tocopherol. Pistachio nut oils are rich in phytosterols, which have been shown to counter arteriosclerosis, the accumulation of fatty deposits in blood vessels.
Smoke Point: 300 degrees F
Common Uses: To flavor rice dishes and as dipping oil.