Feeding and Diet

Walnuts are revered since ancient times as symbol of intellectuality since their kernels have convoluted surface inside the shell resembling as that of brain! The nuts are enriched with many health-benefiting nutrients, especially ?-3 fatty acids that are essential for optimum health.

The nuts are edible kernels of the fruits from tree belonging to Juglandaceae family, in the genus: Juglan. Juglan species plants are medium sized, semi-tropical, deciduous trees believed to be originating in the mountain ranges of Central Asian or southern Europe region.

There exist at least 30 varieties of walnut cultivars. The three most popular verities grown for commercial purpose are the English or Persian walnut (Juglans regia), the Black walnut (Juglans nigra), and the White or butternut walnut (Juglans cinerea). Commercially, the nuts are being cultivated in the United States of America, Romania, France, Turkey, and China. After plantation, the plant takes approximately four years until it produces its first major crop.

During each season, the fruits are ready for harvesting by August when the thick green hull begins to crack to expose the light brown colored “in shell” (with shell) walnut. Each nut is roughly spherical in shape, about the size of medium sized lemon weighing about 10-15 g enclosing edible kernel.

In structure; the walnut kernel consists of two uneven, corrugated lobes, off white in color and covered by a paper thin, light brown skin. The lobes are partially attached to each other. Oil extracted from the nuts, apart from cooking, has also been used in as base or carrier oil in medicine, and aromatherapy.

Health benefits of Walnuts

• The nuts are rich source of energy and contain many health benefiting nutrients, minerals, antioxidants and vitamins that are essential for optimum health.

• 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 help to lower total as well as LDL or “bad cholesterol” and increase 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 helps 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 have 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 sized nuts a day could help scavange disease causing free radicals from the body.

• In addition, they are also 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 co-factor for anti-oxidant enzymes such as glutathione peroxidases.

• Walnuts oil has flavorful nutty aroma and has an excellent astringent properties; 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.

Selection and storage

Walnuts are available in the markets year around. In the store, you may get to see different forms of nuts are available; un-shelled, shelled (without the shell), salted, sweetened, or ground etc. Buy whole “in shelled” or “with shelled” nuts instead of processed ones.

While buying, look for the nuts that should feature bright brown color, compact, uniform in size and feel heavy in hand. They should be free from cracks, mold, and spots and free of rancid smell.

Un-shelled or with shell walnuts can be placed in cool dry place for many months, whereas shelled (without the shell) nuts should be placed inside airtight container and kept in the refrigerator to avoid them turn rancid.

Culinary uses

• The nuts are usually eaten on their own, using nutcracker machine. The kernels can also be enjoyed roasted, salted, or sweetened.

• The kernels are nutty yet pleasantly sweet in taste. Add as toppings in yogurt, pizzas, pies etc.

• Crushed kernels often sprinkled over salads, desserts, particularly sundaes and other ice cream based preparations.

• Candied walnuts are added as seafood toppings.

• They are widely used in confectionery, as an addition to biscuits, sweets, and cakes.

• The nuts are also used to make walnut-butter, which is quite popular; especially among peanut allergy sufferers.

• In the Middle East, walnuts are added along with almonds, dates, raisins ...etc in Ramadan special pastry preparation, ma'amoul.