Walnuts, along with hazelnuts, are the most well-known and widely used nut fruit among Germans. Popular worldwide, walnuts are valued as a delicious snack and as a baking ingredient, among other things. But it is also considered a “superfood” with excellent health-promoting properties.
This is what you should know about the walnut
Walnuts, along with hazelnuts, are the most well-known and widely used nut fruits among Germans. Popular worldwide, walnuts are prized as a tasty snack and baking ingredient, among other things. The product offered in stores as “walnut” is usually the fruit of the true walnut tree (Juglans regia). More rarely, fruits of closely related species such as black walnut or butternut, as well as various hybrids, also appear on the market as walnut. Walnut seed kernels are protected by a green outer covering formed by leaf elements and an underlying cracked, brownish hard shell. The outer shape of the tree’s seed kernels is remotely reminiscent of brain hemispheres. As a rule, the light brownish walnut seeds are three to eight centimeters long. The width is about three to five centimeters. The characteristic flavor of walnut meat combines bitter flavors with a slight sweetness. The nut flesh is light in color and firm to the bite. The original home of the deciduous walnut tree is western Asia. From there it spread to East Asia and Europe as a wild tree and early as a cultivated plant. From Gaul, the tree came to Germania in Roman times. Because of its connection to France and Italy, the tree was long called “Welschbaum” east of the Rhine. From this, via the transitional form “Walchbaum”, it finally developed in the 17th/18th century into the common name used today. A walnut tree can become more than 150 years old. After eight to 15 years it bears fruit for the first time. The trees are most productive at the age of 40 to 80 years (up to more than 50 kg per tree). Walnut trees, which are sensitive to frost, thrive best in areas with mild winters. Therefore, ideal for walnut cultivation are wine-growing areas with their similar climatic conditions.
The main areas of cultivation of the tree are China, Iran, California, Anatolia and Mexico. There are hundreds of varieties of walnut trees, whose fruits differ considerably in shape and size. German importers meet their needs primarily in California. The most widely cultivated varieties there are Chandler, Hartley, Serr, Tulare, Vina and Howard. The peak harvest season in California, as in Europe, is early fall. Major growing countries in Europe are France, Ukraine, Romania and Italy.
Importance for health
Walnuts are among the foods generally considered to be particularly healthy. In particular, they help ensure the elasticity of veins and other blood vessels. Walnut consumption is also said to help stabilize blood cholesterol levels at normal levels. This supports the functions of the heart and blood circulation. Even regular consumption of a few walnuts or small amounts of walnut oil is said to have a positive health effect in this respect and help prevent high blood pressure. As recommended daily ration often 30 g (approximately five to ten nuts) are called. Furthermore, walnuts are said to protect against diabetes and to counteract the development of prostate diseases. According to U.S. studies, there is evidence of a breast cancer inhibiting effect of walnuts. In naturopathy, extracts from walnuts are recommended as a wound and skin ulcer remedy, for diarrhea, and to combat pinworms and tapeworms. In alternative medicine, walnut has long been used as a homeopathic remedy for abscesses, acne and eczema.
Ingredients and nutritional values
Responsible for the beneficial health effects of the nut fruit are its high levels of polyunsaturated fatty acids, antioxidants and vitamins, as well as minerals and trace elements. Walnuts can have a fat content of more than 60%. The proportions of protein and carbohydrates are about 15 and 25%, respectively. The calorific value is 660 kcal/100 g (2700 kj). Only 10% of the walnut fat is based on saturated fatty acids, the rest is determined by unsaturated fatty acids. Therefore, despite the considerable fat content, walnut consumption does not necessarily lead to weight gain if other types of fat are avoided. The proportion of valuable omega-3 fatty acids, including alpha-linolenic acid, which supports heart muscle function, is particularly high at 15%.In addition, walnut has proportions of zinc, phosphorus, potassium, calcium, selenium, sodium and magnesium. In particular, semi-ripe walnuts are extremely rich in vitamin C. Other vitamins present in significant quantities in walnuts are A, B1, B2, B3 (niacin), B5 (pantothenic acid), B9 (folic acid) and E (tocepherol). Phenolic acid components provide the bitterness in the taste.
Intolerances and allergies
Walnuts are generally well tolerated. According to British studies, the likelihood of having an allergic reaction to certain walnut proteins after eating walnuts is about 0.4%. The allergic reactions usually manifest as mild irritation or swelling in the mouth and tongue area. Neurodermatitis episodes can also be triggered. More severe problems such as vomiting and diarrhea or respiratory distress (asthma) and life-threatening shock are rare. Walnut components as coloring agents in cosmetics, inks and foods can cause hyperpigmentation on contact with the skin. Consumption of the histamine-rich walnut is strongly discouraged in histamine intolerant individuals.
Shopping and kitchen tips
Commercially grown walnuts are dried after harvest. This reduces the moisture content to less than ten percent. At the same time, the bitter substance content is lowered. Walnuts treated in this way can be kept in their shells for at least a year if stored properly. Because of their richness in fat, walnuts are sensitive to heat and moisture. They should therefore be stored in a cool, dry and dark place. It is best to store them in suspended nets to ensure uniform ventilation. Individual moldy or rancid nuts must be removed immediately so that the other nuts are not affected. Because walnuts take on foreign odors rapidly, it is advisable to keep them as airtight as possible from foreign influences. Storing opened walnut bags in the refrigerator has a similar effect. Shelled kernels will keep for about a month after opening the package. Walnut kernels can also be frozen if packed in an airtight container. The most aromatic nuts are those that have not been shaken from the tree, but fall from the tree after reaching maturity. Because of their creamy taste among gourmets, freshly harvested walnuts are popular. Their kernels should be freed from the white, extremely bitter-tasting skin before eating. Undried nuts can be kept for only a few days.
Preparation tips
Walnut kernels are mainly eaten as a small treat in between meals directly from the cracked shell. Another possible use is walnut brittle (mixture of chopped walnuts and carmelized sugar). The crunchy kernels are further suitable whole, chopped or ground as an ingredient of salads, pasta dishes, ice cream and as a cake ingredient. Walnut kernels are an excellent base for nut liqueurs, jams and syrups. Pickled sweet and sour, semi-ripe walnuts are an exotic garnish for rice dishes and cold meats. Walnut kernel croutons are an excellent ingredient for soups. Spreads of chopped walnuts mixed with olive oil, mint and anchovy fillets are a tip for breakfast rolls.
