Nuts are ingredients, snacks, food and the source of additional ingredients and other useful compounds. As a component in finished foods, they provide crunch, bursts of flavor and other pleasing attributes in baked foods, confections, and now in salads, coatings for meat dishes and other applications.
There's a fair amount of technology behind nuts these days. They are generally orchard-raised crops and, like all crops, have considerable science behind the steps of planting, harvesting and processing. Despite a bevy of recent research, nuts possess only partially understood nutritional qualities. For sure, they are a high-quality and nutritious accompaniment or ingredient in foods, and they help differentiate a high-end product from a plain one.
If you still think nuts naturally fall off trees, are whacked with a hammer to open and their nutmeats are pried out with a pick, you're a little behind the times. Nuts are big business. Tree nuts, including walnuts, almonds, hazelnuts, pecans, pistachios, pine nuts, and Brazil nuts, are grown in many countries of the world and are important exports and imports. Each of these nuts has a history and a nutrient content that makes them interesting. Their collective growth covers millions of acres worldwide.
Nuts are usually sorted for size, especially if they are cracked mechanically. After they are dried to the optimum level for cracking, (generally below 10 percent moisture) nuts may be chilled to make it easier to take out the nut meat in larger pieces. They are cracked mechanically, often using a roller cracker adapted from grain mills.
Aspirators and/or blowers often are used to separate the nut meats from the shell, as the heavier nut kernel drops down and the shell fragments are blown away. They are usually further sorted by electronic means to avoid any remaining pieces of shell. For a number of years, acoustic grading located debris in partly shelled nuts. White light sorters have also been used. Today's sorters are most likely to be laser sorters that locate non-nut fragments and "zap" the fragment away.
Nuts also may be color sorted to avoid spoiled nut pieces. Moisture and fat content is checked, and they are sometimes further processed into slices, granules or meal. Nuts also may be toasted or roasted.
Special handling required
Meyer also notes, "We changed the fats we use for roasting, eliminating trans fatty acids, and the nuts actually taste better."
Nuts include meaningful quantities of monounsaturated lipids that are good for the heart , but often not so good for mixed food systems, flavorwise, so they require a little special handling. Manufacturers recommend nuts be stored in a closed container in a cool, dark, place, such as a refrigerated storage room. American Almond Co. recommends storing nuts in poly-lined cartons or fiber drums and using them within 30 days.
Candy, baked goods and ice cream products are major users of tree nuts. Ice cream is a tricky application and requires "protecting" the nuts from the moisture of the ice cream, according to Richard Hauber, a creator of ice cream inclusions for Guernsey Bel, a Chicago-based division of Kerry Group (www.kerryingredients.com). "Protecting nuts in ice creams and desserts is usually a process of coating them with sugars to keep the moisture out," he explains.
To make nutty inclusions, Hauber triple-pans nut meats with sugar, caramel, toffee fines, and/or chocolate coating. "Toffee fines will pick up a little moisture from the ice cream, creating a puddle of intense flavor around the pecan, cashew, or walnut, and protects the lipid in the nut. The cold temperature of the ice cream keeps the lipid from going rancid, as long as it's protected from moisture."
Tom Treese, a confectioner and baker and now consultant to food companies, notes the unsaturated fats that make nuts a prized part of diets can be a problem in confections, cookies, and health bars that must have a certain amount of shelf life. Treese likes to use almonds in longer-term shelf-life products because they have the best stability against rancidity.
The best way to formulate with nuts, especially if the cookies or bars need more than six to eight weeks shelf life, is to package them in film that is treated with antioxidants, especially tertiary-butyl-hydroquinone (TBHQ), or to nitrogen-flush the package. When dealing with nuts in products that are more sensitive, Treese suggests nuts that are treated with infrared rays to quickly raise the temperature enough to destroy enzymes that trigger rancidity.
"The temperatures vary from one kind of nut to another," says Treese. "You can treat them with an infrared unit or place them in a mixer-blender and inject steam to reach the temperature necessary to stop enzyme activity. If you are going to use nuts in foods, you have to be careful what fats you use in the formulation. Nuts are not as forgiving as other ingredients. You have to watch moisture levels, water activity and fats."
Another popular use of nuts is in ready-to-eat breakfast cereals. The most popular nut is the almond, often sliced into thin slices and sometimes glazed along with flakes or clusters. The flakes are fairly dry, so there is little moisture transfer, and the carton liner may be treated with antioxidants to prevent off-flavors. There is little additional fat, so interactions that might occur between lipid ingredients are minimized. In some products, cereal clusters are made with nuts added to nuggets and flakes, and coated with a light sugar coating.
Nuts have always been a popular addition to cookies. Now they're playing a role in low-carbohydrate reformulations. Both almonds and hazelnuts are being ground into flour to replace part of the wheat flour in products that claim reduced carbohydrates, says Alex Flyntz, American Almond's national sales manager.
Parco Foods, Blue Island, Ill. (www.parcofoods.com) a manufacturer of frozen cookie dough for in-store bakeries, is using nuts to make healthier cookies. "We're looking at lower carbs and high fiber content, too, and nuts help," says formulator Carol Sinople. "We're careful about which nut is used in formulas we are developing with zero trans fats to be sure the flavors remain good there."
Parco Foods is partial to nuts that have more natural resistance to rancid flavors, including almonds, peanuts, and pecans. Since the company's products include frozen cookie dough, the temperature helps protect the flavors of nuts in the dough.
Partly because of the healthy fats in nuts, they have been popular in foodservice. Because the shelf life is not an issue with freshly prepared foods, nuts are added to sauces, vegetables, meats, salads, desserts and appetizers.
In the move toward more exotic foods, almonds and walnuts are appearing on salads, pecans in pecan-crusted chicken, and pistachios and macadamia nuts are being added to recipes for desserts. Smaller packages of specially sized nuts are designed for use in the home: sliced almonds sized to use on salads, vegetables and fish almondine are found in just about every supermarket, as well as in foodservice packages.
Just like nuts, chocolate is beginning to get recognition for at least some healthy attributes. Chocolate and nuts is a long-running duet in the candy industry, and new pairings are popping up all the time.
M&M Mars recently extended its Snickers candy bar with an almond version, and sales have grown rapidly. "It's an upscale ingredient that's affordable, and the health aspect doesn't hurt," says Marlene Machut, director of external affairs for Masterfoods, the candy and food unit of Mars Inc., Hackettstown, N.J. Almonds also were added to one of the Kudo's Granola Bars as a healthier ingredient, and that has been effective, as well, she says.
On the other side of the chocolate aisle, Hershey a few years back added almonds to its famous chocolate Kisses -- with spectacular results. Now, insiders tell us almonds are a key ingredient in new products under development at Hershey.
Nuts are healthy: The label says so
Last July, the Food and Drug Administration allowed a "qualified" health claim for peanuts and nine tree nuts (almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachio nuts, and walnuts). Responding to a petition from the International Tree Nut Council Nutrition Research and Education Foundation, FDA said there was not sufficient scientific evidence for an unqualified health claim, but did allow the qualified claim.
The qualified claim says, ""Scientific evidence suggests but does not prove that eating 1.5 ounces per day of most nuts [include the name of the specific nut] as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease."
A separate, similar label statement specifically for walnuts also is permitted. A letter of Enforcement Discretion for the qualified health claim for walnuts, which includes the sources of scientific evidence that the FDA relied on for the claim, is available at www.cfsan.fda.gov/~dms.qhcnuts3.html.
A number of medical studies have increased the nutritional excitement behind nuts. One of the most recent was a study that evaluated the effect of almonds on total cholesterol and low-density lipoprotein (LDL or "bad cholesterol"). Briefly, almond-based diets showed reductions in total cholesterol and LDL, while the high-density lipoprotein (good cholesterol) content was maintained. (Details are available from Gene Spiller at The Health Research and Studies Center, 415-948-8540.)
A study at Pennsylvania State University studied the effects of about an ounce of walnuts a day. Researchers found the diet that included the walnuts, which are rich in alpha linolenic acid, produced lower serum cholesterol while also improving vascular function.
While healthy fats have fueled the interest in nuts, they are also rich in anti-oxidants, such as tocopherols that are precursors of vitamin E (alpha, beta, gamma and delta forms), phytochemicals such as stigmasterol, campesterols, and beta-sitosterol. Carotenoids include beta and alpha carotene, cryptozanthin, lutein, minerals such as zinc, calcium, potassium, and vitamins including folate (see table). Nuts also contain selenium, known for its effect against prostate cancer.
"Now consumers know nuts are good for them, and they know eating an ounce and a half will help their cardiovascular system," says Dennis Balint, CEO of the California Walnut Commission, Sacramento, Calif. "Consumers will be more likely to use walnuts and other nuts in a variety of ways. You're going to see increases (of nuts) in packaged salads, garnishes and other uses. Additionally, nut sales won't take away from other purchases, but will add to the total ring."
Major tree nuts
According to the U.S. Department of Agriculture, the total U.S. value of utilized nut production is around $1.91 billion, an increase of about 26 percent from 2001. Major varieties grown in the U.S. are almonds, walnuts, pecans, pistachio, hazelnuts, macadamia nuts and a few specialty products like pine nuts and hickory nuts.
We're talking only of tree nuts here, which excludes peanuts.
Many nut growers are members of cooperatives, which buy, process and market their members' nuts. Diamond Walnut, the biggest grower of walnuts, was formed in 1912, and now sells more walnuts than any other groups. It has 1,900 grower-owners, mostly on relatively small family farms. The co-op has expanded beyond walnuts, adding hazelnuts, pinenuts, almonds, pecans, and macadamia nuts, and is currently the leading walnut supplier to 80 percent of the nation's ingredient buyers.
Will current nut orchards be able to keep up with demand? According to the Tree Nut Assn., sales look pretty strong, but more trees are coming on line, and some of the new varieties bear earlier and are more prolific.
Key nutritional components of popular nuts
Content per 100 gm Pecan Hazelnut Almond Walnut Total fat (gm) 71.97 60.75 50.64 65.21 Protein (gm) 9.17 14.95 21.26 15.23 Carbohydrate (gm) 13.89 16.70 19.74 13.17 Fiber (gm) 9.6 9.7 11.8 6.17 Saturated fat (gm) 6.18 4.46 3.81 6.13 Monosaturated fat (gm) 40.81 45.65 32.16 8.93 Polyunsaturated fat (gm) 21.61 7.92 12.21 47.15 Zinc(mg) 4.53 2.45 3.36 3.09 Calcium (mg) 70 114 248 0 .98 Potassium (mg) 4.10 680 728 441 Folate (mcg) 22 11.3 29 98
Table based on data from USDA and the International Tree-Nuts Council