Nuts contain a large quantity of fat, protein, some starch, and very little water. The shell forms on the average about half the nut. Nuts are not easily digested, owing to the dense cellulose framework which surround the kernel of the nut. They can, however, be bought prepared (cleaned), and can be ground down; in both cases this renders them more easily digestible. Protoid nuts, prepared by Christian, are an excellent sample of a highly nutritious and easily digested food. Most of the nuts are eaten raw, but chestnuts and cocoa-nuts, almonds and walnuts are used also in confectionery. For some specially prepared nut preparations and butters, see Vegetarian Cookery, p. 522.
The composition of the common nuts is given in the following table. Their very high proportion of fat and proteins make them a very valuable foodstuff if carefully employed.
Comparative Value of Edible Portion.
Brazil Nuts . .. .
Hickory Nuts .. .
Pecan Nuts ...
Walnuts, English .
Letchi . ...
Almonds (sweet and bitter) contain a large amount of fat and protein, but no starch and very little sugar. The small proportion of sugar makes them of great use in the treatment of diabetes. They are ground and made into almond cakes and biscuits. Salted almonds are eaten with dinner as an aid to digestion. Macaroons are a pleasant form of cake, composed of almonds and sugar. The bitter almonds contain hydrocyanic acid, and are only used medicinally.
Walnuts contain a large proportion of protein and fats; eaten freely between meals, they sometime have a very laxative effect. They are usually eaten ripe and dry with dessert; the unripe fruit is made into walnut ketchup. The walnuts are taken before the shell has hardened; they are beaten to a pulp and the juice separated by straining; salt and vinegar are added, also spices, and after considerable boiling down the ketchup is bottled and may be kept for years. The green walnut is used as a salad in France, mixed with onion, vinegar, salt, and pepper.
Chestnuts contain a small amount of oil and a large amount of carbohydrates. In Italy they form a valuable adjunct to the food supply. They may be boiled, roasted, or ground. When mixed with flavourings and maize meal, they form polenta. Flat cakes are made from chestnut flour and water, and baked between flat stones. The meal may be used for soups, puddings, and as the basis of the stuffing of poultry.
Brazil nuts, pecan nuts, beech nuts, hazel nuts, hickory nuts, pine kernels, filberts, all contain much oil, and are imported in enormous quantities from Spain for the sake of their oil. Barcelona nuts are kiln dried before export, and keep indefinitely; if hazel nuts or their cultivated varieties, cobs and filberts, are not dried, they lose their flavour unless kept in airtight vessels. Butternuts easily become rancid after being shelled.
Cocoa-nuts are very indigestible even when thoroughly desiccated and grated. The nuts are eaten both ripe and unripe by the natives of the tropics, and the juice (cocoa-nut milk) is drawn out and drunk. They contain fully 70 per cent of cocoa-nut oil or cocoa-butter, which is used as a food or for lighting and lubricating purposes. The butter is suitable for cooking, and can be used instead of margarine. Acorns are used as food in some countries. They are used like chestnuts, and like them contain starch. They are described as a very good fruit, savoury to the taste and healthful to the body.
Pistachio, a nut native to Syria, has a green-coloured kernel; it is much used on account of this for confectionery and for ices.