Nuts and Seeds

Nuts are high in fat and calories, but taken in moderation they can be part of a healthful diet. Nuts are not only flavorful, but, ounce for ounce, also full of nutrients.

Most nuts are seeds or the dried fruit from trees. Peanuts, which are commonly thought of as nuts, are actually legumes. They belong to the same family as peas and beans.

The word "nut" can be confusing. The term originally referred to an edible kernel surrounded by a hard shell. In its most scientific definition, the term now refers to a single-seed fruit with the seed surrounded by a dry, tough fruit. This definition works for hazelnuts, beechnuts, and chestnuts, but it does not "fit" almonds and walnuts (because their surrounding fruits are theoretically edible) or peanuts (which are legumes). Adding to the confusion, Brazil nuts and pine nuts are not nuts, either. They are actually seeds, and sunflower seeds are actually fruits.

Nuts are a versatile food. They can be eaten fresh, cooked, and, sometimes, with their shell. They are available whole or chopped, salted and unsalted. In addition, products made from them include butters, oils, and spreads.

Nutrition

The protein in nuts and seeds lacks an essential amino acid called lysine, which can be gained from legumes and animal products. Although nuts are high in calories for their size, they are also considered a "nutrient-dense" food. They contain a lot of nutrients in relation to their calories.

Nuts are also rich in different plant compounds. Flavonoids, for instance, are found in all nuts. These antioxidants help reduce the formation of free radicals in the body that may contribute to cancer and cardiovascular disease. Relative to their size, nuts are also among the best plant sources for protein.

Nuts are generally high in fat. In most cases, more than 75 percent of their calories comes from fat (the exception being chestnuts -only 8 percent of the calories are from fat). But, on the plus side, it is the "right kind" of fat. Most of the fat in nuts is monounsaturated and polyunsaturated, with the exception of the coconut and palm kernel. Unlike saturated fats (typically found in red meats and dairy products), these fats do not appear to increase blood cholesterol levels. In small amounts, monounsaturated and polyunsaturated fats may actually lower cholesterol levels.

Watch the salt, however. Nuts do not come by that naturally -it is an added feature. If you need to limit your salt intake, look for products with no added salt.

Selection

Purchase nuts with a clean, uniform appearance. When buying nuts in the shell, look for whole, unbroken shells. To ensure maximal freshness, look for nuts that are vacuum-sealed in bags, jars, or other containers.

Storage

Because of their high fat content, nuts and seeds should be stored in dark, cool, dry conditions in closed glass or plastic containers to prevent rancidity. Unshelled nuts keep better than shelled nuts, which can become rancid in a few weeks unless frozen. Most unshelled nuts will keep 2 months to a year in the refrigerator or a year or more in the freezer.

Safety Issues

Allergies to nuts are one of the most common kinds of food allergies. Symptoms of an allergic reaction include itching, hives, nasal congestion, shortness of breath or wheezing, swelling, upset stomach, nausea, cramps, heartburn, gas or diarrhea, light-headedness, or fainting. If you suspect that you have any food allergies, see an allergist for a careful evaluation.

Nuts and seeds

ALMOND
Although almonds are native to the warmer regions of western Asia and northern Africa, they grow well in California, where 99 percent of domestic almonds are grown.
The almond fruit is the edible seed of sweet almond trees. Almonds are teardrop shaped and surrounded by a shell and an outer fleshy hull. They can be either sweet or bitter. The sweet types have a delicate yet distinctive flavor, but the bitter almond is inedible in its raw form because it contains traces of the poison prussic acid, a cyanide compound. During the late 19th century, cross-breeding among sweet almonds created new varieties that include the California, Mission, Price, Carmel, and the Nonpareil (the most popular variety today). Since then, approximately 30 additional varieties have been developed and are grown commercially.
Nutritionally, almonds have more calcium than any other nut and are an excellent source of iron, riboflavin, and vitamin E. More than 60% of the fat comes from monounsaturated fat.

BEECHNUT
Beech trees grow in the temperate forests of Europe, North America, Asia, and North Africa and can be up to 120 feet tall. Beechnuts are simply the seeds (or nuts) enclosed in prickly burrs that fall to the ground in the autumn. Beechnuts look like small chestnuts and taste like hazelnuts. More than 10 species of beech trees produce nuts.
Beechnuts are an excellent source of thiamin and riboflavin and a good source of iron. Monounsaturated and polyunsaturated fats provide more than 80% of the fat content.

BRAZIL NUT
The Brazil nut grows on an evergreen tree, mainly along the Amazon, Orinoco, and Rio Negro rivers of South America. About 6 inches in diameter and resembling a coconut, the fruit of the Brazil nut tree has 18 to 20 nuts within its hard shell. Inside, the triangular nuts are arranged like the wedges of an orange. It is the white kernel inside this shell that is eaten. This kernel is rich, creamy, and sweet and is a good source of phosphorus and thiamin and contains some calcium. This nut also has a high fat content, although most of it is unsaturated.
Only after the fruits have fallen to the ground are they harvested and chopped open to obtain the nuts. Because the trees grow wild in the heart of the Amazon jungle, the nuts can be shipped only during the rainy season, when streams and rivers are navigable. Although the nuts are obtained only in Brazil, most are exported, and native Brazilians rarely eat Brazil nuts.
The Brazil nut is also known as the para nut, butternut, cream nut, and castanea. Oil from the nut is used to make soap or as an industrial lubricant.

CASHEW NUT
India is the world's leading producer of cashew nuts, although other important producers include Mozambique, Tanzania, Kenya, and Brazil.
Cashew trees produce a fruit-like stalk called the cashew apple (even though it is the shape of a pear). Attached to the end of the cashew apple is the cashew nut, which has a smooth, ash-colored outer shell. The edible kernel of the nut varies between three-quarters of an inch and an inch in length. Its generic name, Anacardium, refers to a heart shape, but cashews have more of a kidney shape.
It is impossible to buy cashews in the shell because the edible kernel is covered with an inner shell, and the space between the inner and outer shells is filled with a thick, caustic, toxic oil (related to poison ivy). Unshelled, unroasted cashew nuts will burn the mouth and lips and raise blisters on the skin.
Nutritionally, cashews are an excellent source of iron, phosphorus, and zinc and a good source of riboflavin, thiamin, and potassium. The primary source of fat in cashews is monounsaturated fat.

CHESTNUT
Chestnut trees are found in Asia, Europe, and North America, and their fruit has been made popular in the lyrics of a Christmas carol. The trees that bear chestnuts were first cultivated in China about 5,000 years ago. Mount Olympus, home to the gods of ancient Greece, was said to have had an abundance of chestnut trees.
Chestnut trees are also long-lived. Some trees that were grafted more than 500 years ago are still alive. The trees are also adaptable to poor land. The nuts are harvested by hand once they have fallen from the burr, the name for the spiny outer covering. Trees typically start bearing nuts after about 25 years.
Chestnuts can range in size from a half inch to more than an inch, depending on the variety. They have one rounded side and one flat side and one rounded end and one pointed end. The roasted kernel is soft, meaty, and sweet.
The common American chestnut, native to the eastern United States, once dominated the forests of Maine to Georgia. But this tree is now nearly extinct because of a tree blight caused by a fungus. Today, only a small number of trees survive.

GINKGO NUT
The ginkgo nut grows on what is considered the oldest known living species of tree. It has remained virtually unchanged for 250 million years and is considered a living fossil. The ginkgo nut is the seed of an inedible, apricot-like fruit that is well known for its strong, some might say offensive, odor. Nuts borne from female trees have hard, buff-colored shells that are pointed on either end. The meat inside has the same shape and color, is soft, and has a delicate, sweet taste. Although the ginkgo tree is commonly grown in U.S. cities because it is resistant to air pollution, many people are unaware that it bears nuts and that they can be eaten.
In Asia, ginkgo nuts and the fan-shaped leaves from the tree (Ginkgo biloba is the scientific name) have been used in traditional medicine for thousands of years. Extracts and powders derived from ginkgo leaves are among the top-selling herbal supplements sold in the United States, where they are promoted as being a memory aid.
From a nutrition standpoint, ginkgo nuts are an excellent source of phosphorus, potassium, copper, thiamin, and niacin.

HAZELNUT
The grape sized nuts have a thick, woody, brownish red shell that readily separates from the kernel. Nuts grow from leafy husks that open as the nut ripens. The nuts begin to drop from the trees in August. In September or October, they are swept up, washed, and then dried. They are sorted for size and then sold for processing. Hazelnuts are referred to by a variety of names, including filbert or cobnut.
There are 10 major species of hazelnut trees. The most commonly grown are the European, the American, and the Turkish hazelnut. Various hybrids are based on these types. These hybrids include the Winkler, Duchilly, and the Barcelona, which is thought by many hazelnut fanciers to produce the finest nuts.
Nutritionally speaking, hazelnuts are an excellent source of iron, magnesium, phosphorus, potassium, and thiamin and a good source of niacin. Monounsaturated fat is the primary source of fat in hazelnuts.

LOTUS SEED
The lotus plant and especially its flowers have been used as a motif in the arts of the ancient cultures of India, China, and Egypt for centuries. Although many people know it is grown for its ornamental flowers, the lotus plant also has edible roots and seeds. The creamy seeds add a mild flavor to cuisine in many Asian countries.
In addition to the seeds, the roots of the lotus plant can be eaten. When sliced and cooked, the light brown, starchy roots have a crisp texture. They are commonly used as a vegetable in Asian dishes. Even the leaves of the plant may be eaten. Young leaves can be eaten raw. Mature leaves may be used to wrap rice, meat, and fruit dishes before they are steamed.
Lotus seeds are referred to by a variety of names. Common ones include Indian lotus, hasu, and nelumbium.

MACADAMIA NUT
Native to Australia, the macadamia tree was named for the naturalist Dr. John MacAdam. According to legend, he was the first to find the nuts edible.
The macadamia nut is enclosed in a very hard, brownish shell, and the kernel is off-white in color. Each nut is about half an inch to an inch in diameter and is enclosed in a thin, fleshy husk. This husk opens as the nut matures. The slightly sweet, creamy, rich flavor of the nutmeat has acquired a "gourmet" reputation and a hefty asking price.
Macadamia nuts have the highest fat and calorie content of any nut, but they are an excellent source of magnesium, copper, and thiamin and a good source of iron and niacin. The fat in the macadamia nut is primarily monounsaturated fat.
The tree that bears macadamia nuts was introduced to some regions of the United States in the 1880s. It was not until the 1930s, however, that a real consumer audience made the macadamia industry possible. Historically, Hawaii has supplied 90 percent of the world's macadamia nuts. Growers in California and Florida also have begun contributing to domestic production. Macadamia nuts are also grown in Brazil, Costa Rica, Guatemala, Venezuela, Jamaica, South Africa, and Samoa.

PECAN NUT
Belonging to the same family as walnuts, pecan trees can be found growing wild from Illinois to Texas and Maryland to Florida. In fact, more than 100 varieties of pecans are cultivated in the United States. Commercial cultivation of pecans, however, is limited to warm states. Georgia produces more than a third of the total U.S. production, which totals about 200,000 tons of unshelled pecans annually.
Pecans are one of the most widely cultivated nuts in the world. The nut itself is elongated and wrinkled, resembling a walnut, and has a buttery flavor. The shell surrounding pecans is shiny, brown, and easily cracked. Most of the fat in pecans is unsaturated. In addition, pecans are an excellent source of many nutrients, including phosphorus, thiamin, copper, and zinc, and a good source of iron and potassium. More than half of the fat in pecans is monounsaturated fat.

PISTACHIO NUT
Pistachio nuts grow in clusters on the pistachio tree, which grows wild throughout central and western Asia and is cultivated in warmer areas of the world.
The nuts are enclosed in fleshy husks. The nut itself has a hard, thin, tan shell that partially splits open when the nut is ripe. The shells may be dyed red or blanched white by distributors to hide imperfections. Inside the shell is a smooth, pale-green kernel wrapped in a fine brownish skin. This kernel has a delicate and sweet flavor, which lends itself to desserts.
Shelled and unshelled nuts should be kept in an airtight container in the refrigerator, where they will keep for 3 months. Pistachios are available year-round. From a nutrition perspective, pistachios are an excellent source of iron, magnesium, phosphorus, potassium, and thiamin. The main source of fat in pistachios is monounsaturated fat.

SAFFLOWER SEED
The safflower plant has been cultivated in India, China, Persia, and Egypt for centuries and it was only introduced in the United States in 1925. India still remains the largest producer of safflower seed.
Common names for safflower seeds include safflower, false saffron, and saffron thistle. Safflower seeds are about a quarter of an inch long and elongated.
They are an excellent source of iron, magnesium, thiamin, and riboflavin and a good source of potassium and niacin.

SESAME SEED
Sesame seeds are small, oval, and flat and have a paper-thin, edible hull. They may be white, yellow, brown, red, or black. Lighter-colored seeds are considered preferable to dark seeds.
Sesame seeds are 40 to 60 percent oil by weight. They are an excellent source of iron, thiamin, riboflavin, and phosphorus and a good source of potassium. Polyunsaturated fat is the primary source of fat.

SQUASH SEED
Cultivated worldwide, squash probably was first gathered by indigenous people around 8000 B.C., primarily for its seeds. European settlers arriving in North America found it was a common crop grown by American Indians.
Although most people are familiar with eating the flesh of squash, the seeds of squash by themselves are both tasty and nutritious. The most popular squash seed eaten in the United States is the pumpkin seed, which is flat with one rounded end and one end that tapers to a point. The seeds are off-white and approximately three-quarters of an inch long. They enclose a green kernel that is delicately nutty in flavor. In Mexico, pumpkin seeds are known as pepitas and are popular in many dishes.
The seeds of winter squash are also commonly eaten. The plants are harvested when the fruits and, hence, the seeds are fully ripe. Summer squash, in contrast, is eaten before it and its seeds are fully ripe. Seeds from acorn squash, buttercup squash, and butternut squash are also edible. The seeds are a healthful addition to your diet, being an excellent source of iron, phosphorus, and potassium and a good source of thiamin and riboflavin. A little less than half the fat comes from polyunsaturated fat.

SUNFLOWER SEED
With more than a hundred species, the sunflower genus is thought to be native to either western North America or South America, although it now grows worldwide. The United States and the former countries of the Soviet Union are among the largest producers of sunflower seeds.
Sunflower seeds are about a quarter of an inch long, angular, and grayish green, tan, or black. They are enclosed in thin shells. Often, these shells are striped in black and white. Two main varieties of sunflower are cultivated commercially. The Russian variety is grown mainly for oil because the seeds contain more than 40 percent oil by weight. The North American variety has larger seeds and is grown for human consumption and for bird food.
Although high in calories and fat, sunflower seeds contain mostly unsaturated fat. In addition, they are a rich source of nutrients, including folic acid, niacin, potassium, and zinc. They are also high in fiber. Sunflower seeds are best kept in a cool, dry place. If shelled, they should be stored in the refrigerator to prevent rancidity.

WALNUT
Walnut is the common name for about 20 species of deciduous trees that include the hickory and pecan tree. The two most common species are the black walnut and the English, also known as the Persian, walnut.
The fleshy green fruit of the black walnut encapsulates the nut and cushions it when it falls from the tree. Effort is required to pry the edible kernel from the nut's thick, woody shell. The inside of the fruit may stain your hands.
The kernel of the English walnut however, is more easily removed from it shell, which is generally thinner and easier to crack. In addition, the husks of English walnuts separate when the fruit is mature allowing the nut to drop out. Partly for these reasons, the English walnut is the more commercially cultivated species.
Nutritionally, walnuts are an excellent source of phosphorus, zinc, copper and thiamin and a good source of iron, and potassium. More than 70 percent of the fat comes from polyunsaturated fat.