Walnut seeds are a high density source of nutrients, particularly proteins and essential fatty acids. Walnuts, like other tree nuts, must be processed and stored properly. Poor storage makes walnuts susceptible to insect and fungal mold infestations; the latter produces aflatoxin—a potent carcinogen.
A mold infested walnut seed batch
should not be screened and then consumed; the entire batch
Walnuts are rounded, single-seeded stone fruits of the walnut tree. The walnut fruit is enclosed in a green, leathery, fleshy husk. This husk is inedible. After harvest, the removal of the husk reveals the wrinkly walnut shell, which is in two halves. This shell is hard and encloses the kernel, which is also made up of two halves separated by a partition. The seed kernels — commonly available as shelled walnuts — are enclosed in a brown seed coat which contains antioxidants. The antioxidants protect the oil-rich seed from atmospheric oxygen thereby preventing rancidity.
should not be screened and then consumed; the entire batch
Walnuts are rounded, single-seeded stone fruits of the walnut tree. The walnut fruit is enclosed in a green, leathery, fleshy husk. This husk is inedible. After harvest, the removal of the husk reveals the wrinkly walnut shell, which is in two halves. This shell is hard and encloses the kernel, which is also made up of two halves separated by a partition. The seed kernels — commonly available as shelled walnuts — are enclosed in a brown seed coat which contains antioxidants. The antioxidants protect the oil-rich seed from atmospheric oxygen thereby preventing rancidity.
The two most common major species of walnuts are grown for their seeds — the Persian or English Walnut and the Black Walnut. The English Walnut (J. regia) originated in Persia, and the Black Walnut (J. nigra) is native to eastern North America. The Black walnut is of high flavor, but due to its hard shell and poor hulling characteristics it is not grown commercially for nut production. The commercially produced walnut varieties are nearly all hybrids of the English walnut.
Other species include J. californica, the California Black Walnut (often used as a root stock for commercial breeding of J. regia), J. cinerea (butternuts), and J. major, the Arizona Walnut.
Walnuts are late to grow leaves, typically not until more than halfway through the spring. They also secrete chemicals into the soil to prevent competing vegetation from growing. Because of this, flowers or vegetable gardens should not be planted too close to them.
The husks of walnut contains a juice that will readily stain anything it comes into contact with. It has been used as a dye for cloth.
The worldwide production of walnut seeds has been increasing rapidly in recent years, with the largest increase coming from Asia. The world produced a total of 2.55 million metric tonnes of walnut seeds in 2010; China was the world's largest producer of walnut seeds, with a total harvest of 1.06 million metric tonnes. The other major producers of walnut seeds were (in the order of decreasing harvest): United States, Iran, Turkey, Ukraine, Mexico, Romania, India, France and Chile.
The average worldwide walnut seed yield was about 3 metric tonnes per hectare, in 2010. Among the major producers, eastern European countries have the highest yield. According to the FAO, the most productive walnut seed farms in 2010 were in Romania, with yields above 23 metric tonnes per hectare.
The United States is the world's largest exporter of walnut seeds. The Sacramento and San Joaquin valleys of California produce 99 percent of the nation’s commercial English walnut seeds.
Advantage of Walnut
They are rich in monounsaturated fatty acids (about 72%) like oleic acid and an excellent source of all important omega-3 essential fatty acids like linoleic acid, alpha-linolenic acid (ALA) and arachidonic acids. Regular intake of walnuts in the diet helps to lower total as well as LDL or “bad cholesterol” and increases HDL or “good cholesterol” levels in the blood. Research studies suggest that Mediterranean diet that is rich in mono-unsaturated fatty acids, and omega-3 fatty acids help to prevent coronary artery disease and strokes by favoring healthy blood lipid profile.
Eating just as much as 25 g each day provides about 90% of RDI (recommended daily intake) of omega-3 fatty acids. Research studies have suggested that n-3 fatty acids by their virtue of anti-inflammatory action help to lower the risk of blood pressure, coronary artery disease, strokes and breast, colon and prostate cancers.
They are rich source of many phyto-chemical substances that may contribute to their overall anti-oxidant activity, including melatonin, ellagic acid, vitamin E, carotenoids, and poly-phenolic compounds. These compounds have potential health effects against cancer, aging, inflammation, and neurological diseases.
Scientists at University of Scranton, Pennsylvania had recently discovered that walnuts have highest levels of popyphenolic antioxidants than any other common edible nuts. 100 g of walnuts contain 13541 µmol TE (Trolex equivalents) of oxidant radical absorbance capacity (ORAC). Eating as few as six to seven average size nuts a day could help scavenge disease causing free radicals from the body.
In addition, they are an excellent source of vitamin E, especially rich in gamma-tocopherol; contain about 21 g per 100 g (about 140% of daily-required levels). Vitamin E is a powerful lipid soluble antioxidant, required for maintaining the integrity of cell membrane of mucus membranes and skin by protecting it from harmful oxygen-free radicals.
These nuts are packed with many important B-complex groups of vitamins such as riboflavin, niacin, thiamin, pantothenic acid, vitamin B-6, and folates.
They also very are rich source of minerals like manganese, copper, potassium, calcium, iron, magnesium, zinc, and selenium. Copper is a cofactor for many vital enzymes, including cytochrome c-oxidase and superoxide dismutase (other minerals function as co-factors for this enzyme are manganese and zinc). Zinc is a co-factor in many enzymes that regulate growth and development, sperm generation, digestion and nucleic acid synthesis. Selenium is an important micronutrient, which functions as a co-factor for anti-oxidant enzymes such as glutathione peroxidases.
Walnut oil has flavorful nutty aroma and exhibits excellent astringent properties. Applied locally, it helps to keep skin well protected from dryness. It has also been used in cooking, and as “carrier or base oil” in traditional medicines in massage therapy, aromatherapy, in pharmaceutical and cosmetic industry.
Munch a handful of walnuts a day and you will have enough recommended levels of minerals, vitamins, and protein.
They can reduce the risk of breast cancer
Eating about 28 walnut halves a day provides antioxidants and phytosterols that may help reduce the risk of breast cancer, according to a study at the Marshall University School of Medicine in West Virginia. Mice were fed a daily diet with the human equivalent of two ounces (60 g) of walnuts. Compared to mice fed a control diet, the walnut eaters had significantly decreased breast tumour incidence and a slower rate of tumour growth.
Eating about 28 walnut halves a day provides antioxidants and phytosterols that may help reduce the risk of breast cancer, according to a study at the Marshall University School of Medicine in West Virginia. Mice were fed a daily diet with the human equivalent of two ounces (60 g) of walnuts. Compared to mice fed a control diet, the walnut eaters had significantly decreased breast tumour incidence and a slower rate of tumour growth.They're packed with omega-3 fatty acids
A diet rich in omega-3s is beneficial in reducing depression, attention-deficit hyperactivity disorder (ADHD), cancer and Alzheimer’s disease and there’s also strong evidence that omega-3s counter inflammatory diseases such as rheumatoid arthritis and Crohn’s disease.
They can reduce risk of diabetes
Women who reported eating one ounce (30 g) of nuts at least five times per week reduced their risk of type 2 diabetes by almost 30 percent compared to those who rarely or never ate nuts, say researchers at the Harvard School of Public Health. The mono- and polyunsaturated fats in nuts are good for insulin sensitivity.
They contain antioxidants that boost heart health
A new study from the University of Scranton in Pennsylvania shows walnuts have higher quality antioxidants and a mix of more healthful antioxidants than any other nut.
They can help you deal with stress
A diet rich in walnuts and walnut oil may help the body deal better with stress. Research published last year in the Journal of the American College of Nutrition found that walnuts and walnut oil lowered both resting blood pressure and blood pressure responses to stress in the laboratory. The researchers said the study shows that a dietary change could help our bodies better respond to stress.
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