Walnuts are edible kernels obtained from tree belonging to the Juglandaceae family, in the genus, Juglan. The nuts have been revered since ancient times as the symbol of intellectuality since their bi-lobed kernels inside the hard shell feature convoluted surface resembling as that of the human brain! They enriched with many health-benefiting nutrients, especially omega-3 fatty acids that are essential for optimum health.
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 at least 30 different cultivars types of walnut grown world-over. However, only three popular varieties grown for their commercial purposes are English or Persian walnut (Juglans regia), Black walnut (Juglans nigra), and the White or butternut walnut (Juglans cinerea). Commercially, they are being cultivated in the United States of America, Romania, France, Turkey, and China. After plantation, the tree takes approximately four years until it produces its first major crop.
During each season, walnut fruits can be ready for harvest by August, when their thick green hull (thin-cover) begins to crack open to expose light brown, hard-shelled “walnut” inside. Each nut features roughly spherical shape, about the size of a medium-sized lemon, weighing about 10-15 g, and enclosing single (bi-lobed) edible kernel inside.
Oil extracted from the walnut kernels has been employed as base or carrier oil in medicine, and in aromatherapy, apart from cooking.