By Kimberlee J. Burrington
Nuts always have been a part of many traditional baked goods, confectionery products and ice cream. Adding nuts to foods is synonymous with adding value, but they also add flavor and texture appeal to many other foods.
For centuries, nuts were considered healthy until fat calories became a concern about a decade ago. Then suddenly, they were declared fattening, and not considered part of a low-fat, healthy diet.
However, nuts nutritional image is improving fast and they are finding their way into more non-traditional foods. People have been hammered with the message of low-fat and fat-free foods for quite some time, so the healthy image of nuts has been slow to grow, says Maureen Ternus, M.S., R.D., nutrition coordinator, International Tree Nut Council, Davis, CA. If you take a second look at the composition of nuts, you will see that they are quite a good-tasting nutritional package. Each nut has its own unique texture, flavor, visual appeal and nutritional balance that give product developers new reasons to add nuts to a formulation.
Commonly consumed tree nuts include walnuts, pecans, hazelnuts, macadamias, Brazil nuts, cashews, pine nuts and almonds. Peanuts, the seeds of a legume, grow beneath the soil. Although each nut varies in composition, research indicates that diets that include nuts result in measurable health benefits. Recent studies show that people who eat a serving of nuts several times per week decrease the incidence of deaths due to coronary heart disease (CHD), hypertension, congestive heart failure and stroke.
Three epidemiological studies have linked reduced CHD risk rates with nut consumption. The Adventist Health Study, a prospective cohort study published in 1992, involving about 31,000 California Seventh Day Adventists, examined the independent relationships between the intake of 65 foods and the risk of myocardial infarction or death from CHD. Results indicated that the frequency of nut consumption had a highly significant inverse association with the risk of both fatal and non-fatal CHD. Those who consumed nuts one to four times per week had a 25% decreased CHD mortality risk, compared to those who ate nuts less than once a week. Consuming nuts five or more times per week resulted in roughly a 50% reduction in CHD risk, compared to eating nuts once a week or less.
The Iowa Womens Health Study, published in a 1996 issue of the New England Journal of Medicine, supported the relationship between increased nut consumption and reduced CHD risk among women. This epidemiological study of 34,000 Iowan women found an inverse relationship between nut consumption and death from CHD after five years of follow-up. Women who ate nuts two or more times per week had a 40% reduced risk of dying from CHD.
The most recent study to support nuts cardioprotective effect is from the Harvard University, Boston, Nurses Health Study. Beginning in 1976, the study has regularly collected medical and lifestyle data from 120,000 women, helping to identify risk factors for CHD and cancer. The most recent report from the study was published in the 1998 British Medical Journal. The results showed that women who ate more than 5 oz. of nuts per week had a 35% reduction in total risk of CHD, compared to women who ate only 1 oz. of nuts per month or none at all.
One randomized, parallel study conducted in 2000 (that has not yet been published) by Kathy McManus and Frank Sachs at Brigham and Womens and Harvard University involved consumption of tree nuts, peanuts, canola and olive oil and weight loss. They compared two different groups of overweight adults, one group on a typical low-fat diet (25% fat) and the other group on a higher-fat diet (as much as 38%) with the additional fat coming from tree nuts, peanuts, canola and olive oil. Both groups lost the same amount of weight but after 18 months, it was the higher-fat group that maintained their weight loss. Triglyceride levels also showed more improvement in the higher-fat group.
The almighty almond
Botanically speaking, the almond is a fruit, an ancestor of other stone fruits like nectarines, peaches, plums and cherries. Its thought to have originated in ancient China and central Asia. Explorers carried almonds along to eat while traveling between Asia and the Mediterranean and the almonds they dropped along the way grew well in the fertile ground of Turkey, Iraq, Iran and Syria. Spain and Italy actually became the first major almond producers, and in the New World the Spanish monks setting up missions planted almond trees along Californias coast. Settlers later discovered that almonds grew better in the more Mediterranean-like climate of central California.
Now, more than 500,000 acres of land produce the U.S. food industrys four major almond varieties: Nonpareil type, Mission and Mission types, California type and Carmel type. Nonpareils have the widest range of uses; their thin outer shell and smooth kernel make them easy to blanch and cut for processed forms. By comparison, the wider Mission almond has a more wrinkled, darker skin and a stronger flavor. Missions tend to be unsuitable for blanching but hold seasonings well and adhere readily to other foods, such as snack mixes and ice creams. Roasting further enhances their strong flavor. The California type represents a number of varieties with shells of medium thickness and a slightly darker skin than the Nonpareil. They are easily blanched and mainly used in manufactured products. The Carmel type has a soft shell and commonly is used for blanching and roasting. Carmel types can substitute for Nonpareil and California almonds due to their good processability. Natural or blanched, almonds can be whole, sliced, diced and slivered.
There are more forms of almonds available than any other nut, says Stacey Kollmeyer, senior manager, communications, Almond Board of California, Modesto, CA. Some of the options include almond paste, or marzipan, almond butter, and almond meal or flour. The form chosen decides the almonds appearance, texture, flavor and application. Natural almonds provide a more astringent taste than blanched almonds, while roasting contributes a more intense almond flavor. Sliced almonds improve visibility or identity in a finished product.
Marzipan, or pate d amandes, a soft, spreadable paste made from shelled, blanched, ground almonds mixed with sugar, is used for Danish or croissant fillings, or just chocolate-coated, a candy popular in Germany. In some German marzipan, European bitter almonds are mixed with California sweet almonds to achieve a distinct almond flavor, says Sam Cunningham, Ph.D., director of R&D, Blue Diamond Growers, Sacramento, CA.
Almond butter can be made with whole natural, roasted or blanched almonds, which are ground until creamy and spreadable. Almond butters can replace other nut butters in icings, cookies and brownies. Almond meal or flour is made with blanched almonds pressed into fine particles. Almond meal can bind and thicken sauces, provide flavor and mouthfeel to smoothies and milk shakes, or enhance texture of pastas, breads, cookie, and pie dough.
In a 1999 survey of 500 food technologists, published by the Almond Board of California, the most desirable attributes of almonds selected were: versatility, crunch, nutrition, consumer appeal and perceived added value. For new formulations, 41% chose almonds as their favorite nut. The single largest usage of almonds is in chocolate bars, says Cunningham.
Almonds have been described as buttery, crunchy, subtle and rich, says Kollmeyer. These flavors can complement both sweet and savory foods. Almonds are the No. 1 nut used in cereal, confectionery and bakery applications, she says, noting that according to the survey, 60% of breakfast cereal product developers named almonds as their favorite nut. Almonds are well-known in such applications as rocky road ice cream, chocolate bars, biscotti, granola and cheese spreads, but also appear in many side dishes, salads and main entrées particularly in Middle Eastern, Mediterranean and Asian dishes. There is even a non-dairy beverage made from almonds, containing more vitamin E and calcium than similar rice and soy beverages.
We have seen a 25% increase in domestic sales of almonds in the past year, says Kollmeyer. Recent increases in almond usage is tied to the introduction of new mini-bite candy bars and energy bars, she says. One very important consumer attitude affects almond use: Increased consumer awareness of health and nutrition information has been driving increased consumption of almonds, says Cunningham.
Almonds have a nutritional composition of about 21% protein, 51% fat, 20% carbohydrate and 12% dietary fiber. The fatty-acid breakdown totals up to 4% saturated fatty acids, 32% monounsaturated and 12% polyunsaturated. The monunsaturated fat is primarily oleic acid, the same type of monounsaturated fatty acid found in olive oil. There is more calcium, potassium, magnesium, vitamin E, riboflavin and niacin in a 1-oz. almond serving than in most other nuts. A 1-oz. serving of almonds (20 to 25 almonds) supplies as much calcium as one-quarter cup of milk, 21% of the recommended Daily Recommended Intake (DRI) for magnesium and 15% of the DRI of phosphorous.
Almonds are considered an outstanding source of vitamin E, containing 26 mg per 100-gram serving, says Cunningham. A 1-oz. serving of almonds supplies almost one-half of the DRI for vitamin E (15 mg) in the readily absorbed d-alpha tocopherol form. Vitamin E is believed to play a role in preventing heart disease, certain cancers and cataract formation.
As a protein source, almonds are high in arginine and low in lysine. Studies indicate that this amino acid combination contributes to a reduced CHD risk. Combining almonds with grains provides a high-quality, complete source of protein. Almonds also contain many phytochemicals, a class of biologically active compounds that may promote health and may play a role in cancer and cardiovascular disease prevention. The whole area of phytochemicals is so new that many of the methodologies for their detection and quantification are still in development, says Ternus.
Cunningham explains that soon, we may see enhanced health and nutrient claims allowed for almonds and possibly fractionation of some of the nutritional components into new ingredients.
A peek at pecans
Native to the Mississippi valley region, pecans were a staple of the early Native American diet; they appear to have ground the kernels into a flour and used it in breads and stews, or boiled it in water and used it as a seasoning for food. Pecans became an especially important part of their diet in the winter because other foods were not available; settlers later used pecans for trading.
Today, Georgia is the largest pecan producer, followed by Texas, New Mexico, Oklahoma, Louisiana, Alabama and Mississippi. Pecan trees are one of the largest fruit-bearing trees. Four common pecan varieties out of the more than 500 identified are Stuart, Desirable, Schley and Western Schley. Stuarts resistance to disease, large nut size and high nut production makes it one of the most important pecan cultivars. Desirables which are bigger than Stuarts and mature earlier are one of the best varieties for roasting and salting because they retain their light color upon roasting. Schley pecans have a superior flavor but a more slender shape, which is less visually desirable.
Pecans are dried to about 3.5% to 4.5% moisture for long-term storage. USDA sizing ranks pecan halves from Small Topper at 750 halves per lb. and higher to Mammoth at 200 to 250 halves per lb. Color is one of this nuts most important quality indicators. Lighter-colored pecans are considered more attractive, while consumers often associate a dark color with rancidity the color will darken as the nuts mature, but it is not necessarily a good indicator of rancidity. Fancy grade is the lightest color with standard and amber, the mid-range and darkest colors, respectively. Pecan kernels have a firm texture and a characteristic sweet, nutty flavor and aroma.
Pecans frequently pop up in bakery foods, ice cream and confections. The first thing that comes to mind when you think of pecans, is pecan pie, and that may never change, says Buddy Leger, chairman, Georgia Pecan Commission, Cordele, GA. But, pecans have applications far beyond the dessert realm, such as snacks, salads, puddings, meats, cereals and vegetable dishes. The flavor is compatible with most foods, combining well with sugar, salt and/or spices. Like most nuts, pecans are available roasted or raw, in wholes, halves, pieces, granules and meal. Whole pieces add visual interest as a decoration on the top of baked products. Pecan halves and pieces often are used in batters and doughs to add texture and nut visibility.
Pecans used for ice cream are roasted, while raw pecans are used for baked products because they are roasted during the baking process, says Leger. A pecans crunch adds texture differentiation and provides the characteristic flavor for butter pecan ice cream. The grooved surface helps hold coatings in frozen novelty applications. Raw or roasted pecan granules are ideal when combined with strong cheeses, such as blue. Dishes like pecan-encrusted trout, leafy salads and new side dishes have helped to increase the consumption of pecans, says Leger. For instance, picture pecans in a wild rice soup or sprinkled over greens as a pecan basil vinaigrette. Hot or cold cereals benefit from the added crunch and sweet nutty flavor of pecan pieces. Caramel turtles or praline pecans would hardly exist without the pecan.
Outside of pecans organoleptic benefits, they also deliver a health message. When people started thinking about low-fat diets about eight to 10 years ago, they didnt want to eat pecans, says Leger. Like most nuts, pecans contain a substantial amount of fat. Pecans have about 19 grams of fat, 5 grams of carbohydrate, 2 grams of fiber and 2 grams of protein per 1-oz. serving. The fat profile calculates to about 7% saturated, 53% monunsaturated and 21% polyunsaturated fat. Pecans are considered a good source of oleic acid, thiamin, magnesium, protein and fiber. Oleic acid helps to lower total blood cholesterol and maintain HDL levels, important for good cardiovascular health. Pecans also contribute g-tocopherol and phytochemicals with potential health benefits. With the right kind of awareness program to make people aware of the health benefits of pecans, the future of pecans is great, adds Leger.
The peanut gallery
Americans consume more than 6 lbs. of peanuts and peanut products each year. The peanuts origin is thought to be South America, where Spanish explorers later spread the crop throughout the United States. The majority of peanuts are cultivated in Georgia. Four varieties varying in size and flavor are U.S.-grown: Virginia, Valencia, Spanish and Runner. Virginia and Valencia typically are marketed as in-shell nuts, while Spanish and Virginia varieties often find their way into candy and nut mixtures. Baked foods and peanut butter use the Runner type, which have a higher oleic to linoleic acid ratio compared to the other varieties, giving this peanut greater storage stability. Runners also have more vitamin E, which helps to increase their shelf life.
Peanuts are one of the most economical and easiest ways to add texture to a food. They are tasty roasted and diced as a salad or dessert topping, or just by the handful. Truly a ubiquitous nut, peanuts and peanut butter appear in ice creams, confections, baked products, snacks and cereals. They also are the most kid-friendly nut. For the adult taste buds, there are gourmet peanut butters and wonderful peanut-based Thai, Chinese and Indian sauces.
Though classified as a legume, they still have many of the same health benefits as tree nuts. Peanuts and peanut butter are a good source of folic acid, which, during early pregnancy, prevents neural tube defects. One ounce of peanuts or 2 oz. of peanut butter contain about as much fiber as one-half cup of broccoli. A 1-oz. serving of peanuts contains more than 10% of the DRI for protein. Peanuts also contain nearly one-half of the 13 essential vitamins necessary for body growth and maintenance. Almost 80% of the fat in peanuts and peanut butter is saturated.
Once known by their red color, pistachios were a Middle Eastern delicacy imported to the United States. Tannins in the hull mottle or stain the shell if they arent processed soon after harvesting. American importers used to dye the nuts to hide any mottling resulting from antiquated harvesting methods. Today, however, very few consumers still prefer the red-shelled nuts.
Todays pistachios were first commercialized in California, in 1976. The Kerman variety is the most common, yielding a large nut with a light-colored shell. The kernels characteristic green color comes from chlorophyll. The natural split the consumer sees in the shell is formed as the kernel grows and pushes against the shell as it matures on the tree. At ambient temperatures, pistachios have at least a one-year shelf life. Pistachio nuts will lose flavor during their shelf life, but they will not go rancid, says Tom Mack, director of quality assurance, Paramount Farms, Lost Hills, CA.
Shelled pistachios for ingredient use are relatively new. In the past, pistachio ice cream was formulated with almonds and artificial pistachio flavor. Now, consumers expect natural pistachio flavor and real pistachios in ice cream and lots of other applications. The major ingredient use for pistachios is in ice cream, but energy bars, trail mixes and chocolate bars are some new applications for pistachios, says Mack. Pistachios are available in whole-kernel, diced, sliced, slivered and meal forms. Dry-roasted and oil-roasted types work well in food applications. Oil roasting is used to retard moisture pick-up by the pistachio in high-moisture food applications such as ice cream, he says.
Many of the same applications for traditional nuts, such as almonds or pecans, take on a whole new identity with the addition of pistachios. Pistachio biscotti or a dark-chocolate pistachio bar create new visual and flavor appeal as new product ideas. These applications dont require a roasted nut. Raw pistachios are typically used for bakery and confectionery applications, says Mack.
Baking a nut-containing product will develop the typical roasted nut flavor. Nut lipids are very important precursors for roasted- or toasted-nut flavors, and the protein and carbohydrate components also play a part as flavor precursors during heating, via the Maillard reaction. Two types of flavor compounds are responsible for heated nut flavors. Lactones, such as g-octalactone and g-decalactone, derived from direct, thermally induced lipid degradation, are the first type of compounds. Heterocyclic nitrogen or oxygen compounds such as pyrazines and furans are the second type of flavor compounds. The same components that play a part in the pistachios texture and flavor attributes provide many nutritional benefits.
Pistachios are similar to cashews in total calories (164) and total fat (13 grams) per 1-oz. serving. The fat composition consists of 15% polyunsaturated, 62% monounsaturated and 13% saturated fat. Each 1-oz. serving contains more than 10% of the daily value for dietary fiber, vitamin B6, thiamin, magnesium, phosphorous and copper. Pistachios are especially rich in phytosterols, compounds directly associated with lowering cholesterol levels. A serving of pistachios has as much thiamin as a serving of cooked rice (196 mg per oz.). The amount of vitamin B6 (0.07 mg) in a 1-oz. serving of pistachios is comparable to a standard 3-oz. serving of pork or chicken.
Hailed by the Romans as the nut of the gods, walnuts are one of the oldest tree nuts known. Their popularity began many centuries ago in the Middle East when they were shipped and traded throughout the ancient world. Like almonds, Spanish missionaries brought walnuts to California, the state that now supplies the majority of the U.S. walnuts.
Walnuts, which range in color from extra light to light to amber, are available in halves, pieces, small pieces and meal.
Along with peanuts and pecans, walnuts are vulnerable to rancidity and odor absorption from improper storage and handling because of their high fat content. A fresh walnut has a delicate, slightly astringent flavor due to the presence of phenolic acids, which also are associated with antioxidant properties.
Traditional bakery, confectionery and ice cream applications represent the largest use of walnuts, says Thomas J. Payne, consultant, Thomas J. Payne Market Development, San Mateo, CA. Walnuts exhibit an excellent flavor synergy with chocolate baked products, such as walnut brownies or chocolate cookies with walnuts. Walnuts accept sweet and savory flavors very well, he adds.
A Waldorf salad relies on walnuts for added crunch and flavor impact. Non-traditional walnut uses, such as the 1999 emergence of several veggie burgers with walnuts, are becoming more common. Product developers of vegetarian burgers recognize that walnuts have many essential amino acids to help meet the nutritional requirements of their formulation, says Payne. Walnuts provide 8.4% of the DRI of protein per 30 gram serving. Like some of the other nuts, the introduction of ethnic foods has presented new dishes highlighting walnuts. The volume of walnuts used in new food applications has been on the rise, he says. Middle Eastern entrées and sauces, Hispanic foods like chiles and nogato, and Asian entrées are some fast growing non-traditional areas for walnuts.
Todays big interest in walnuts also highlights their nutrient content and nutritional benefits. Walnuts are unique in their high omega-3 fatty-acid content (2.57 grams per oz.), in comparison to other nuts, says Payne. This omega-3 fatty acid, alpha, alpha-linolenic acid, plays an important role in the regulation of inflammatory immune reactions and blood pressure, in brain development in utero and in early postnatal life during cognitive-function development. Omega-3 fatty acids also function in the prevention of CHD, stroke and cancers of the breast, colon and prostate.
Walnuts are a good alternative to fish as a source of omega-3 fatty acids, says Ternus. We require two fatty acids in our diets, alpha-linolenic and linoleic alpha-linolenic acid is the parent compound of the omega-3 fatty-acid family and linolenic acid is the parent compound of the omega-6 family. There is no RDI for either fatty acid but the joint Food and Agriculture Organization-World Health Organization Committee recommends a linoleic acid intake of 4% to 10% of energy and an optimal intake of 800 to 1100 mg per day of alpha-linolenic acid. Research has shown that there is treatment potential for mild hypertension, rheumatoid arthritis, auto-immune disease (lupus, nephropathy), Crohns disease and inflammatory skin diseases with consumption of omega-3 fatty acids. In comparison to the other nuts, walnuts are high in vitamin B6 and folic acid, and also contain vitamins E, A and C, thiamin, magnesium, iron, copper, zinc, phosphorous, potassium and calcium.
A different type of walnut, American Eastern black walnuts are botanically related to the California-grown English walnuts but are native to North America. These trees grow in the central and eastern United States, ranging from Minnesota to Virginia, with Missouri as the No. 1 producer. In fact, 99% of black walnuts are harvested in the wild.
The black walnut is smaller than the English walnut, and the shell is much tougher to crack. The nuts must be crushed through rollers, so halves and large pieces are virtually impossible to produce in substantial amounts. The fat content is slightly lower than in English walnuts, but the shelf life is comparable. Its flavor is more intense and aromatic, so a lesser amount will provide a similar flavor impact.
Other tree nuts
Some of the other tree nuts include cashews, macadamias, hazelnuts and Brazil nuts. Cashews, produced in Thailand and India, add quality, eye appeal, texture and a smooth, buttery taste. Highlighting Asian entrées, stir-fry dishes and salads, cashews enhance chicken, turkey and fish. Cashews are trendsetters when it comes to bakery and confectionery items, like cashew caramel pie. Cashews have 30% of the DRI for copper, the highest of all the tree nuts, are a good source of phosphorus and have the second highest magnesium level (19% DRI).
Macadamias are grown in the Hawaiian Islands, New Zealand and Australia. They bring a high-quality, upscale reputation to baked products. Their smooth, creamy texture and distinct flavor make them perfect for encrusting fish or blending with mango, papaya and other tropical fruits, and dry roasting brings out their rich buttery flavor. While macadamias have the highest fat content, they also have one of the lowest levels of polyunsaturated fat and saturated fat of all the nuts.
Hazelnuts, or filberts, are grown in Oregon. They are the preferred nut for bakery products in Europe and are especially suited for Italian patisserie and French confectionery treats. Complementing rich chocolate desserts, hazelnut flavor has been a new flavor trend for upscale coffee beverages. Hazelnuts have the second highest level of vitamin E of all the nuts, at 23% of the RDI in a 1-oz. serving and the highest level of vitamin B6, with 9% of the DRI in a 1-oz. serving. They have a fat level of 54.5%, more than 80% of which is monounsaturated.
Like the other nuts, many forms are available: roasted or raw, skin on or off, and whole, sliced or diced. Hazelnut paste consists of a sweetened mixture of ground hazelnuts and sugar that has a grainy texture. This can provide a wide range of applications from baked goods to sauces with body, sweetness, flavor and moisture. The unsweetened version, hazelnut butter, has a consistency like peanut butter.
Brazil nuts have all of the DRI for selenium in one nut, says Ternus. Brazil nuts are the large seeds of giant trees grown in the Amazon jungle. They develop in clusters of eight to 24 nuts inside a hard 4 to 6 in. pod that has the appearance of a coconut. Today, brazil-nut producers include Brazil, Peru, Bolivia, Columbia, Venezuela and the Guineas. They are marketed as in-shell and shelled products. Brazil nuts can be eaten raw, roasted and salted in ice cream, chocolate and bakery products.
Incorporating nuts into a product for added texture and flavor also will result in a long list of nutrients for the formula and a host of additional health benefits to the customer.
Although not usually categorized as nuts, sunflower seeds and pine nuts have similar applications as tree nuts and peanuts. Pesto sauce just wouldnt be the same without pine nuts. There are a number of different varieties, including the pignolia, from the stone pine (Pinus pinea), native to the northern Mediterranean, and the Chinese pine nut from Asia. In the United States, two types are harvested in the wild, but not grown commercially: hard-shelled pinyon nuts and Nevada soft-shell pine nuts. These oily seeds contain about 61% fat and are about 1 cm in length. They add exotic flavors and a mild crunch to pizza and other traditional dishes like lamb, veal, pork, chicken and fish. Roasting enhances their flavors, adding zip to salads, pastas or entrées with a Southwest flair.
Sunflowers are a native North American plant, now commercially grown on the plains of North and South Dakota. Most sunflowers are grown for oil, but non-oil-production types give us confectionery sunflower seeds, with the largest sizes commanding premiums. Dehulled confection-type seeds are available to add taste, texture and value to salads, veggie wraps, legume-based side dishes, muffin and quick bread toppings. Sunflower seeds are a good source of fiber and vitamins B6 and E.
The only potential fly in the health-promotion ointment is nut allergies. Roughly 1% of the population is allergic to nuts. About half of food-allergy sufferers suffer from a nut allergy, says Maureen Ternus, M.S., R.D., nutrition coordinator, International Tree Nut Council, Davis, CA. A higher percentage of the population is allergic to peanuts than to tree nuts; in fact, peanuts are the No. 1 item causing food allergies.
Because food allergies have no cure, avoiding the culprit is critical. The Food Allergy Network reports an estimated 100 to 200 people die each year from food-allergy-related reactions. Therefore, providing proper labeling to a nut-containing formulation is critical so those with a potential reaction can avoid these foods. For the remaining 99% of the population, the list of benefits from nut consumption is long.
Kimberlee J. Burrington is the whey applications program coordinator for the Wisconsin Center for Dairy Research in Madison, WI. She received her B.S. and M.S. degrees in food chemistry from the University of Wisconsin-Madison. Her industry background is in bakery and dairy.
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