Page:Foods and their adulteration; origin, manufacture, and composition of food products; description of common adulterations, food standards, and national food laws and regulations (IA foodstheiradulte02wile).pdf/469

 which the early housewives used for dying homespun cloth. The bark of the tree also contains to a greater or less extent the same coloring matter. The kernel of the walnut, that is, the edible portion, is extremely rich in oil and protein and has a very pleasant taste. Like other nuts the walnut is best during its first winter, since on longer keeping the oil tends to become rancid and the fruit unpalatable.

White Walnut (Juglans regia L.).—The white walnut, commonly known as the English walnut, is grown very extensively in France. All the departments of south central and southeastern France grow these walnuts as a valued crop. The best walnut orchards are at an altitude of from 600 to 900 feet. Only the outer or exposed limbs produce perfect nuts. In planting the most important precaution is to give the trees plently of room, 15 yards is about the usual distance at which they are planted. The trees are cultivated and fertilized with manure and commercial fertilizers every two or three years. A bearing orchard of these white walnuts in France is worth from four to five hundred dollars per acre and may yield a revenue of from seventy-five to one hundred dollars a year per acre. The nuts ripen from the middle of September to the end of October. These nuts are used largely in America as a food, for which purpose the kernels are carefully extracted in halves, commonly known as "walnut halves." In France an excellent table oil is expressed from the dry nut which for many culinary purposes is valued as highly as olive oil. After extraction the oil cake is used for stock food. The white walnut is supposed to have been originally introduced from Persia, though it is commonly known as the English walnut. In the United States the butternut tree is commonly known as the white walnut.

The composition of the kernel of the dry walnut is shown by the following data:

Edible portion:

Water,                    2.5 percent Protein,                 16.6 " Fat,                      63.4 " Total carbohydrates,     16.1 " Ash,                       1.4 "

As purchased:

Refuse,                  58.1 percent Water,                    1.0 " Protein,                   7.0 " Fat,                     26.6 " Total carbohydrates,       6.7 " Ash,                       .6 "

General Discussion.—A brief description has been given above of the principal edible nuts used in the United States, accompanied by a statement of their chemical composition. The character of the food products is well