What is Edamame?

Edamame are young soybeans in pods. Soybeans are native to East Asia and have been consumed by the Chinese, Japanese and Korean people for over 2,000 years. Asians have enjoyed soybeans in the form of tofu (first known to be used in 164 A.D.); as soymilk; as a tasty ingredient in soups and entrees; and finally as beans eaten directly from boiled pods similar to the Edamame that we eat today.

The word, "Edamame" originates from the Japanese phrase "beans from the branch", likely because soybeans grow in a cluster with stems connecting the pods. The Chinese refer to Edamame as “mao dou”, which is literally translated as “hairy bean”, referring to the fine hair covering the outside of the pods.

Nutritional Benefits of Edamame

Edamame are packed with nutrition. The beans contain many of the organic compounds and amino acids essential for good health and are naturally high in fiber and protein. Beneficial compounds that are found in Edamame include isoflavones such as genistein and daidzein, which act as antioxidants, and alpha-lineolic acid, which may be beneficial for cardiovascular health. A 1 cup serving of Edamame contains 8 grams of fiber, equivalent to 1/3 of the U.S. recommended daily allowance, and 17 grams of protein *[1]

Varieties of Edamame

Soybeans come in a number of varieties, but not all are used to make Edamame because not all young soybeans have good flavor and texture. There are several varieties of soybeans currently being made into the Edamame that are sold in the U.S. They include varieties with fanciful names such as “Envy” or “Lucky Lion”; others with more utilitarian names like “Buker’s Favorite” or “Butterbeans”; and finally those with traditional Japanese names like “Sayakomachi” or “Sapporo Midori”. The beans of all Edamame varieties contain about 40% protein by weight, and are considered a very good source of natural (non-processed) vegetable protein.

History of Edamame in the United States

Edamame was originally introduced to the U.S. by Japanese restaurants that used it as a snack food to accompany sake or beer. In fact, a well-known Edamame variety served in Japanese restaurants is called “Beer Friend”. According to Japanese custom, the pods are served with rock salt. Over the past few years, however, as Edamame has begun to be perceived as a healthy food, restaurants are now serving them with less salt or no salt at all.

Since the late 1990’s, as the public has become more aware of the nutritional and health benefits of soy products, Edamame has increased in popularity. The attractiveness of soy and Edamame has been encouraged by findings that HRT (Hormone Replacement Therapy) could potentially increase the risk of breast cancer *[2]. A diet rich in soy products, which contain plant estrogens, is therefore being promoted by some doctors as an alternative to HRT. Studies also show that soy genistein (an isoflavone) can improve elasticity of the arteries, and can improve cardiac health. In 1999, the FDA determined that diets low in fat and cholesterol that include 25g of soy protein per day may reduce the risk of heart disease *[3].

As the popularity of Edamame continues to grow, many grocery stores and wholesale clubs now stock frozen Edamame. Americans can now enjoy at home the pleasures of the traditional and proper way to eat Edamame, which is to squeeze the beans out of the pods using teeth or fingers directly into the mouth.

How to Identify High Quality Edamame

High quality Edamame has a bright green color, which signifies a soy plant that is productive and resistant to disease. Individual pods should contain larger-sized beans that exhibit good flavor and texture. A general rule is that a bag of high quality Edamame should contain 165 to 170 pods in 500g (17.64 oz) of a ready-to-eat product. Generally speaking, the smaller the pod count per bag, the better the quality. This is due to the pods containing larger beans and the lack of “single-bean-pods”, which are usually less flavorful.

In order to produce high quality Edamame, it is important for the supplier to select a good variety of soy plant that is well suited for the climate and soil in which it is grown. This will result in higher quality beans. In the past five years, a great deal of research has been done on developing new soy plant varieties in Taiwan and Japan in order to improve the taste and texture of Edamame.

After being picked, Edamame should be washed to remove the soy pod hair; sorted to remove single-bean-pods and pods with rust spots (caused by damage during the growing or processing stages); cooked; and finally quick-frozen to preserve freshness before being packaged.

[1] Source: Nutritiondata.com. For more information, please access the following link.

[2] Sources: Heart and Estrogen/Progestin Replacement Study follow-up (HERS II), JAMA. 2002;288:49-57; 58-66 and the Women's Health Initiative randomized controlled trial. JAMA. 2002;288:321-333.

[3] FDA 21CFR 101.82.