Adzuki bean (Vigna angularis) is a legume (Fabaceae, Leguminosae) of the butterfly family subfamily (Faboideae). The shrubby crop is cultivated in East Asia and thrives best in subtropical locations. Its pea-sized fruits are also called red soybeans.
Here’s what you should know about the adzuki bean.
The shrubby adzuki bean is grown in East Asia and does best in subtropical locations. Its pea-sized fruits are also called red soybeans. The adzuki bean has been cultivated in Japan, China and Korea for thousands of years. It is closely related to other beans such as the mung bean. More recently, it has also been cultivated in South America, the southern United States, some countries in Africa, and New Zealand. In Japan, adzuki bean is the second most important legume after soybean. Depending on the intensity of cultivation, yields range from 4 to 30 dt/ha. The mostly annual plants reach a height of 20 to 90 cm. The dark red seeds, about the size of a pea, grow in the legumes. They can be distinguished from kidney beans, which are also red, by their shape and a typical white line. It is mainly the ripe seeds that are used. The green pods are processed fresh into vegetables and salads. Some of the plants are also used as green fodder and fertilizer. The dry adzuki beans have a sweet, nutty taste and are processed and used in various ways: the beans are canned or dried. Some are ground and the flour is used to make soups and pastries, jams, candies and sweet drinks. In Japan, adzuki beans are used to make a sweet bean paste (anko). The bean sprouts are sold as aduki. Popular desserts include the soup shiruko and the confection yokan, made from ground adzuki beans, sugar and agar agar. In China, sweet bean paste is wrapped in flatbreads or made into an adzuki cake with syrup. Legumes have a much higher status in Asian cuisine than in Western cuisine. The adzuki bean first came to the West as part of the macrobiotic diet. In dried form, adzuki beans are now available in Asian and organic food stores. In addition, adzuki bean is used as food for cockatiels and has also been used in a Japanese shower gel.
Importance for health
Adzuki beans are easier to digest than European garden beans. With a protein content of 20 to 21 percent, they are among the most protein-rich vegetables and provide the body with all the essential amino acids, vitamins B1 and B2, and iron, potassium and calcium. Their fiber promotes digestion, relieves the intestines and helps lower cholesterol levels. Adzuki beans are also believed to have antioxidant properties. A phytoestrogen is also believed to have preventive effects against breast cancer. The adzuki bean is of great importance in traditional Chinese medicine (TCM). Due to its diuretic effect, it is used primarily for kidney and bladder problems, but also for tumors of all kinds, for obesity and in obstetrics. Since in TCM anxiety is associated with the kidney, the adzuki bean is also considered a courage bean. Another effect is the expulsion of heat, which is why adzuki bean is used to treat inflammation. According to TCM, the adzuki bean combines cooling and expelling effects and therefore counteracts damp heat. Finally, adzuki bean benefits nursing mothers because it promotes blood circulation and milk production and prevents mastitis.
Ingredients and nutritional values
| Nutritional information |
Amount per 100 gram |
| Calories 329 | Fat content 0.5 g |
| Cholesterol 0 mg |
Sodium 5 mg |
| Potassium 1.254 mg | Carbohydrates 63 g |
| Dietary fiber 13 g |
Protein 20 g |
Of all types of beans, the adzuki bean has the highest protein content and the lowest fat content. In addition to important minerals and trace elements, it contains a particularly high concentration of potassium, 1,254 mg per 100 grams.Furthermore, 100 grams of adzuki beans contain:
- Vitamin A 17 IU
- Vitamin C 0 mg
- Calcium 66 mg
- Iron 5 mg
- Vitamin D 0 IU
- Vitamin B6 0.4 mg
- Vitamin B12 0 µg
- Magnesium 127 mg
Intolerances and allergies
Allergic reactions to legumes are common, but can vary widely. While peanut can cause the most severe reactions even in trace amounts, reactions to beans, lentils and peas – and therefore also to adzuki beans – are rare. They occur, if at all, in weak, clinically irrelevant intensities. In this context, it is interesting to note that legume allergies can also develop via pollen sensitization, especially to grass pollen. The reason for this is the occurrence of the allergenic proteins in different species. People with histamine intolerance are generally advised against eating legumes. In this case, it is necessary to check whether the adzuki bean triggers intolerance symptoms.
Purchasing and kitchen tips
Adzuki beans are usually commercially available dried. Stored in a cool, dry place, they will keep for years. It is also possible to make sprouts by germination. Adzuki sprouts must be blanched for about 5 minutes before consumption, as they contain a toxin when raw. Adzuki beans are mostly used to prepare casseroles and stews, but also desserts. Due to their sweet taste, the beans harmonize well with hearty vegetable dishes. Before cooking, they are soaked in cold water for 8 to 12 hours (preferably overnight). The soaking water is not used further. The beans are put on with plenty of fresh water and cooked on low heat. The cooking time is 40 minutes and may be longer if the water is very chalky. Salt and other spices are added only towards the end of the cooking time. The cooking process must not be interrupted. It is also possible to postpone the entire cooking process of adzuki beans to the day before and keep them in the refrigerator until the actual preparation of the dish in question. The recommended amount as a side dish for two people is 100 grams of adzuki beans.
Preparation tips
The simplest dish with adzuki beans is the 1:1 mixture with rice known from macrobiotics – an easily digestible and strengthening dish. For this, rice and adzuki beans are cooked for about two hours on very low heat and only then seasoned. In vegetable stews, the appropriate vegetables are added to the cooking process of the adzuki beans depending on the cooking time. Seasoning is always done at the end. Stews with pumpkin are popular – but there are no limits to experimentation. For the sweet spread (anko), 200 grams of adzuki beans are cooked for about 90 minutes on the lowest flame, and 10 minutes before the end of cooking time, cooked chestnuts and cane sugar are added. Then season with orange zest and salt. For sesame balls, a dough is made with rice flour and tapioca flour. Small pieces are filled with sweet bean paste, rolled into balls and rolled in white sesame seeds. The balls are then deep fried in hot oil.
