Eating 2 handfuls of “young” soybeans every day has 6 great benefits for your body!

Author: Xue Qingxin, registered dietitian

Reviewer: Zhang Yu, researcher at Chinese Center for Disease Control and Prevention

Edamame originated in China and has a cultivation history of more than 5,000 years. In fact, edamame is "young" soybeans. They are fresh vegetable soybeans with pods harvested when the pods are full, the pods are green, and the maturity is 60% to 80%. Now is the season for eating edamame. Invite three or five friends to have a plate of edamame and chat for half a day. Edamame boiled in salt water is very delicious and often cannot be stopped. Eating 2 handfuls of "young" soybeans every day, although we can't "paint old soybeans green" to become younger, it does have many benefits to the body! Let me tell you in detail.

1. What are the nutritional properties of edamame?

Edamame has a sweet taste, a special bean flavor, and is also very nutritious!

(1) Protein : As a fresh bean vegetable, edamame has a protein content of 13.1 g/100 g, which is almost as high as pork! No wonder some people say that edamame can be used as both a vegetable and meat. The protein content of edamame is nearly 1.8 times that of peas, and 5 times or even 10 times that of green leafy vegetables such as Chinese cabbage, Chinese cabbage, rapeseed, and spinach. It is also a high-quality protein that is easily absorbed and utilized by the human body.

(2) Dietary fiber : The dietary fiber content of edamame ranks among the highest among vegetables. According to the data in the U.S. Department of Agriculture Nutrition Database, the total dietary fiber content of edamame is 4.2 g/100 g; according to the data in the Chinese Food Composition Table, the insoluble dietary fiber content of edamame is 4 g/100 g, which is 1.8 times, 4.4 times and 5.7 times that of celery, Chinese cabbage and rapeseed, respectively.

(3) Calcium : The calcium content of edamame is 135 mg/100 g, which is 6.4 times that of peas, which are also fresh legumes. Judging from the content alone, the calcium content of edamame is higher than that of milk! However, the oxalic acid content of edamame is not low. If it is not handled properly, it will affect the absorption and utilization of calcium, and its calcium absorption rate is not as good as that of milk.

(4) Potassium : The potassium content of edamame is as high as 478 mg/100 g, which is 1.4 times that of peas and 3.6 times that of cabbage. Eating it is a great way to supplement potassium!

(5) Magnesium : The magnesium content of edamame is 70 mg/100 g, which is better than most common vegetables.

(6) Zinc : The zinc content of edamame is 1.73 mg/100 g, which is 3.8 times that of peas and higher than most vegetables.

(7) Selenium : The selenium content of edamame is as high as 2.48 micrograms per 100 grams! In fact, there are not many foods rich in selenium in our daily diet. They are more abundant in nuts, seafood and animal offal. The selenium content in other foods is generally low. Edamame can be regarded as a "big selenium supplement"!

It should also be noted that edamame has a high calorie content of 131 kcal/100 g. Eating 100 g is equivalent to eating a small bowl of rice. People who want to control their weight should not eat too much every day. Two handfuls of edamame with skin are just right, and the edible part is about 100 g. For people who want to lose fat and gain muscle, replacing part of the staple food with edamame may be helpful.

Figure 1 Copyright image, no permission to reprint

2. What are the specific benefits of eating 2 handfuls of edamame?

(1) Control blood pressure : 2 handfuls of edamame can provide us with 478 mg of potassium and 70 mg of magnesium, which can meet 24.0% and 21.2% of the daily needs of the general population, respectively. Adequate potassium intake in the diet has a significant antihypertensive effect on high blood pressure caused by high sodium; magnesium intake is negatively correlated with high blood pressure. Supplementing with magnesium can reduce vascular tension and vascular tone, helping us stabilize blood pressure.

(2) Prevent constipation : 2 handfuls of edamame can provide us with about 4 grams of dietary fiber. Edamame is rich in insoluble dietary fiber, which can promote gastrointestinal mechanical movement and promote defecation. It is very helpful in preventing constipation and also helps improve intestinal health.

(3) Promote bone health : 2 handfuls of edamame can provide us with nearly 135 mg of calcium, which is more than the calcium intake of eating 200 grams of Chinese cabbage! Eating more calcium-rich foods can promote bone health, increase bone density, and prevent osteoporosis. Regarding the issue of oxalic acid that affects calcium absorption, the oxalic acid content of edamame can actually be reduced during the cooking process, and stir-frying edamame is more effective in removing oxalic acid.

(4) Maintaining immune function : The protein, zinc and selenium in edamame are closely related to the body's immune function. Protein is related to the body's growth, tissue repair, regulation of the internal environment, disease resistance, and brain information transmission; zinc can maintain the structure of cell membranes, maintain the normal function of the immune system, and improve appetite; selenium can upregulate the expression of interleukin-2 receptors, activate lymphocytes, NK cells, and lymphokines, and increase the activity of killer cells, thereby improving immune function.

(5) Regulating hormone balance : Edamame is immature soybeans, and like soybeans, it contains isoflavones. As phytoestrogens, isoflavones can help the body regulate hormone levels and maintain estrogen balance. When the body lacks estrogen, it can replace estrogen and bind to estrogen receptors to play the role of estrogen; when there is too much estrogen in the body, it can interfere with the binding of estrogen to estrogen receptors and play an anti-estrogen role.

(6) Regulating blood lipids and blood sugar : Dietary fiber, plant sterols and unsaturated fatty acids in edamame help regulate blood lipids and blood sugar.

3. How to cook edamame so that it doesn’t turn yellow?

Many people will find that the originally green edamame turns yellow after being cooked. Why is this the case? Is there any way to keep the cooked edamame green?

The main reason why edamame is green is that it contains chlorophyll. The chemical properties of chlorophyll are unstable. Under heating or acidic conditions, it is very easy to turn into pheophytin and turn yellow. Therefore, if you want to keep the boiled edamame green, you have to find a way to prevent chlorophyll from turning into pheophytin.

(1) Boil edamame in alkaline water : Chlorophyll is relatively stable under alkaline conditions, and edamame is not likely to turn yellow. You can add a small amount of baking soda to the water used to boil edamame to create an alkaline environment, but be sure not to add too much to prevent the B vitamins in the edamame from being destroyed, resulting in nutrient loss.

(2) Add some salt and oil : Adding a small amount of salt or oil can achieve the purpose of protecting the color. Before cooking the edamame, soak it in light salt water for half an hour, and then add some salt and oil when cooking the edamame, which can delay the time for the edamame to turn yellow.

(3) Cool after cooking : After cooking, quickly soak the edamame in cold water to cool it down quickly, which helps to preserve its color.

In fact, it doesn't matter whether the cooked edamame is yellow or green. The key is to cook it thoroughly! When the pods of edamame crack, it is cooked. If you put it in cold water, generally continue to cook it for 5 to 10 minutes after the water boils. If you cook it for more than half an hour, it will inevitably turn yellow.

Figure 2 Copyright image, no permission to reprint

4.How to store edamame?

August to October every year is the peak season for edamame harvesting, and many people will buy more at this time to store and eat slowly. So, how should you store the edamame you buy?

The optimum storage temperature for most beans is generally 8-10℃, but the best storage temperature for edamame is 1-5℃, which is conducive to keeping the nutritional content of edamame relatively stable; edamame stored at 1℃ is of better quality and can be stored for half a month or even longer. So, remember to store the edamame you bought in the refrigerator!

In addition, it is best to eat edamame with grains, which can complement the protein and improve the absorption and utilization rate of protein. Let's eat it!

References

[1] Liang Zuanhao, Lin Huaxing, Chen Haiqiang, et al. Effect of storage temperature on the quality of fresh edamame during storage [J/OL]. Food Industry Science and Technology: 1-12 [2023-09-05].

[2] Yang Yuexin. Chinese Food Composition Table, 6th Edition, Volume 1[M]. Peking University Medical Press, 2018.

[3] Xia Wei. Effects of cooking on oxalic acid in vegetables[D]. Suzhou University, 2008.

[4] Sun Changhao. Nutrition and Food Hygiene, 7th edition [M]. Beijing: People's Medical Publishing House. 2017.

[5] Sun Jincai, Yu Ning, Zhang Min. Study on the color protection technology of edamame by blanching[J]. Journal of Food and Biotechnology, 2012, 31(11):1154-1159.

[6] Guo Li, Wang Peng. Effects of blanching on the quality of dehydrated beans[J]. Grain and Oil Processing, 2010, (12): 118-120.