Japanese mustard spinach scientifically known as Brassica rapa var. pervirdis is a leaf vegetable. Commercially, it is cultivated in Taiwan and Japan. Also known as komatsuna, the name is derived from Japanese komatsuna which refers to the greens of Komatsu, Komatsugawa village where it was cultivated heavily during the Edo period. Leafy greens are cooked or also consumed fresh. It is pickled, stir-fried, boiled, added to soups, or used in salads. It is regarded as an excellent source of calcium. Komatsuna leaves could be consumed at any stage of their growth. In mature plants, they are dark green having slender light green stalks which are about 30 centimeters long and 18 cm wide. It is found in spring and autumn and it could not sustain extreme heat and cold for a long time period.
Komatsuna is a Japanese vegetable that is similar to spinach. This vegetable has a number of health benefits and we will discuss the benefits of this Japanese mustard spinach vegetable. Komatsuna is derived from the name of a village in Japan, namely Komatsu. A village in Tokyo, Japan.
This green vegetable seems to be as delicious as the greens spinach. Of course, consuming Komatsuna vegetables has its own health benefits, for those of you who often consume these green vegetables, lets know their benefits.
| Mustard spinach Quick Facts | |
|---|---|
| Name: | Mustard spinach |
| Scientific Name: | Brassica rapa var. perviridis |
| Colors | Dark-green, glossy |
| Shapes | Oblong |
| Taste | Mild |
| Calories | 33 Kcal./cup |
| Major nutrients | Vitamin C (216.67%) Vitamin A (106.00%) Vitamin B9 (59.50%) Calcium (31.50%) Iron (28.13%) |
Basically, mustard spinach is an Asian green that is neither mustard nor spinach. It belongs to the cruciferous family which also includes cabbage and broccoli. It prefers cool weather which makes it suitable for fall, spring, and winter in mild climates.
Nutritional value of Mustard spinach, (tendergreen), raw
Calories 33 Kcal. Calories from Fat 4.05 Kcal.
| Proximity | Amount | % DV |
|---|---|---|
| Water | 138.3 g | N/D |
| Energy | 33 Kcal | N/D |
| Energy | 138 kJ | N/D |
| Protein | 3.3 g | 6.60% |
| Total Fat (lipid) | 0.45 g | 1.29% |
| Ash | 2.1 g | N/D |
| Carbohydrate | 5.85 g | 4.50% |
| Total dietary Fiber | 4.2 g | 11.05% |
| Minerals | Amount | % DV |
|---|---|---|
| Calcium, Ca | 315 mg | 31.50% |
| Iron, Fe | 2.25 mg | 28.13% |
| Magnesium, Mg | 16 mg | 3.81% |
| Phosphorus, P | 42 mg | 6.00% |
| Potassium, K | 674 mg | 14.34% |
| Sodium, Na | 32 mg | 2.13% |
| Zinc, Zn | 0.26 mg | 2.36% |
| Copper, Cu | 0.113 mg | 12.56% |
| Manganese, Mn | 0.61 mg | 26.52% |
| Selenium, Se | 1.2 µg | 2.18% |
| Vitamins | Amount | % DV |
|---|---|---|
| Water-soluble Vitamins | ||
| Calcium, Ca | 315 mg | 31.50% |
| Iron, Fe | 2.25 mg | 28.13% |
| Magnesium, Mg | 16 mg | 3.81% |
| Phosphorus, P | 42 mg | 6.00% |
| Potassium, K | 674 mg | 14.34% |
| Sodium, Na | 32 mg | 2.13% |
| Zinc, Zn | 0.26 mg | 2.36% |
| Copper, Cu | 0.113 mg | 12.56% |
| Manganese, Mn | 0.61 mg | 26.52% |
| Selenium, Se | 1.2 µg | 2.18% |
| Fat-soluble Vitamins | ||
| Vitamin A, RAE | 742 µg | 106.00% |
| Vitamin A, IU | 14850 IU | N/D |
| Lipids | Amount | % DV |
|---|---|---|
| Fatty acids, total saturated | 0.022 g | N/D |
| Palmitic acid 16:00 (Hexadecanoic acid) | 0.011 g | N/D |
| Stearic acid 18:00 (Octadecanoic acid) | 0.005 g | N/D |
| Fatty acids, total monounsaturated | 0.207 g | N/D |
| Oleic acid 18:1 (octadecenoic acid) | 0.033 g | N/D |
| Gadoleic acid 20:1 (eicosenoic acid) | 0.042 g | N/D |
| Erucic acid 22:1 (docosenoic acid) | 0.13 g | N/D |
| Fatty acids, total polyunsaturated | 0.086 g | N/D |
| Linoleic acid 18:2 (octadecadienoic acid) | 0.045 g | N/D |
| Linolenic acid 18:3 (Octadecatrienoic acid) | 0.041 g | N/D |
*Above mentioned Percent Daily Values (%DVs) are based on 2,000 calorie diet intake. Daily values (DVs) may be different depending upon your daily calorie needs. Mentioned values are recommended by the U.S. Department of Agriculture. They are not healthbenefitstimes.com recommendations. Calculations are based on average age of 19 to 50 years and weigh 194 lbs. Source: https://ndb.nal.usda.gov/
Health benefits
Vitamins A and K
Japanese mustard greens are rich in the fat-soluble vitamins A and K. One cup of raw greens gives you 33 percent of the recommended daily intake for vitamin A and 180 percent of the recommended daily intake of vitamin K. Your immune system, vision, and reproductive system depend on vitamin A to work properly. According to the Office of Dietary Supplements, vitamin A may also prevent certain forms of cancer. Vitamin K is essential for blood clotting and may help keep your bones strong as you age. If you take blood-thinning medications, talk with your health care provider about how much vitamin K is safe for you to eat.
Vitamin C
Unlike the fat-soluble vitamins, water-soluble vitamins are not stored in your body and they must come from your diet daily. Vitamin C is one of these necessary nutrients, and one serving of Japanese mustard greens gives you 65 percent of the daily recommended intake. Your body needs vitamin C for the synthesis of certain neurotransmitters and collagen, a protein that strengthens connective tissues and helps wounds heal. Immune function and iron absorption are also enhanced by vitamin C. The vitamin is heat sensitive and degrades with cooking, so eat mustard greens raw to get the most benefit.
- Komatsuna leaves and stems are the storehouses of numerous phytonutrients that have health promotional and disease prevention properties.
- It is very low in calories (22 calories per 100 g raw leaves) and fats. Nonetheless, its dark-green leaves carry plenty of antioxidants, vitamins, and minerals.
- Komatsuna greens are a good source of dietary fiber. Studies suggest that a sufficient amount of soluble and insoluble fibers in the diet helps control cholesterol levels by interfering with its absorption in the gut. The fiber-rich diet also facilitates smooth bowel movements, and thereby, eases constipation as well offers some protection against hemorrhoids and colon cancer.
- Komatsuna is a rich source of antioxidants like flavonoids, indoles, sulforaphane, carotenes, lutein, and zeaxanthin. Indoles, mainly Di-indolyl-methane (DIM) and sulforaphane have proven benefits against prostate, breast, colon, and ovarian cancers by virtue of their cancer-cell growth inhibition, cytotoxic effects on cancer cells.
- Fresh leaves are excellent sources of folates and pyridoxine. 3.5 Oz (100 g) raw komatsuna carries 159 μg or 40% daily recommeneded levels of folates. Folates in the diet help improve anemia and play a role in the prevention of neural-tube defects in newborn babies.
- The greens are also moderate sources of another B-complex group of vitamins such as thiamin, riboflavin, niacin, pantothenic acid, etc. Many of them play a pivotal role as cofactors in the substrate metabolism inside the human body.
- Fresh Japanese mustard leaves are excellent sources of vitamin C. 3.5 Oz (100 g) fresh leaves provide 130 mg or about 144% of RDA. Vitamin C (ascorbic acid) is a powerful natural antioxidant that offers protection against free radical injury and flu-like viral infections.
- Komatsuna leaves are also incredible sources of vitamin-A (provide 9900 IU or 330% of RDA per 3.5 Oz (100 g). Vitamin-A is an essential nutrient required for maintaining healthy mucosa, hair, and skin. Consumption of natural foods rich in flavonoids helps protect from lung and oral cavity cancers.
- The greens are excellent sources of vitamin K. Vitamin-K has been found to have a potential role in bone mass building function by promoting osteoblastic activity in the bone. It also has an established role to play in Alzheimer’s disease patients by limiting neuronal damage in their brains.
- Fresh Komatsuna is an excellent source of several essential minerals such as calcium 210 mg (21% RDA), iron (19% RDA), magnesium, potassium, zinc, selenium, and manganese (18% RDA).
- Regular consumption of Komatsuna in the diet is known to prevent arthritis, osteoporosis, iron deficiency anemia and is believed to offer protection from cardiovascular diseases, asthma, and colon and prostate cancers.
Selection and storage
- Komatsuna can be harvested at any stage- from microgreens to flowering tops. While young, its leaves have a mild flavor and are prepared much like spinach. As the plant grows, the stems become tougher, and flavor grows stronger and hotter, and hence, require a longer cooking time. In the market, look for fresh greens featuring crispy, dark green leaves. Avoid wilt, spotted, or discolored leaves. At home, keep the leaves in the refrigerator soon after buying as they wither soon if kept at room temperature. Although they can be stored for up to 3 days in cold storage, fresh komatsuna greens should be used as soon as possible to get benefits.
Preparation and serving methods
Komatsuna is a popular green-leafy vegetable in the Japanese diet. Fresh leaves, flower buds, and stems are used in a variety of cuisines all over East Asia.
Before cooking, wash the leaves thoroughly in clean running water to remove sand/dirt and then rinse in saline water for about 30 minutes to remove any insecticide residues. Trim away thick petioles and stems.
Here are some serving tips:
- Fresh tender Japanese mustard-spinach greens are eaten raw either as a salad or enjoyed juiced.
- Prepare simple fried rice with eggs and Japanese mustard spinach (小松菜の炒飯).
- In Japan, mature komatsuna leaves are steam-cooked alone or mixed with other greens such as spinach in Ohashi. Boiled greens seasoned with dried bonito flakes, sesame seeds, and soy sauce broth as a dressing to flavor and to tame the pungent, peppery flavor.
- Use in dashi-soups mixing with chicken, mushroom, and chopped green onions.
- Komatsuna can be substituted for napa (Chinese) cabbage for a more highly flavored version of kimchee.
Safety profile
- Reheating of Japanese spinach leftovers may cause conversion of nitrates to nitrites and nitrosamines by certain bacteria that thrive on prepared nitrate-rich foods, such as komatsuna, spinach, and many other green vegetables. These poisonous compounds may prove harmful to health.
- Phytates and dietary fiber present in the komatsuna may interfere with the bioavailability of iron, calcium, and magnesium.
- Komatsuna, being a Brassica family vegetable, contains oxalic acid, a naturally occurring substance found in some vegetables which may crystallize as oxalate stones in the urinary tract in some people. People with known oxalate urinary tract stones are advised to avoid eating vegetables belonging to the Brassica family. Adequate intake of water is, therefore, necessary to maintain normal urine output.
- Komatsuna may also contain goitrogens which may interfere with thyroid hormone production and can cause thyroxin hormone deficiency in individuals with thyroid dysfunction.
Culinary uses
- Young leaves are added to salads or stir-fries.
- Leaves (from older plants) can be simmered, steamed, braised, stir-fried, and pickled in salt.
Japanese Mustard Spinach Properties
- The leaves are spoon-shaped often found on the top of the stem. The stem is generally slender.
- Except that its flavor might be a wee bit off-putting. Also known as Japanese mustard spinach, komatsuna is a variant of the common turnip.
- Like komatsuna, bok choy, rapini, and mizuna are also variants of the turnip and each of these has proven delectable to chefs and home cooks alike.
- Komatsuna is milder in flavor and are extremely versatile than ordinary turnip greens, and that is the reason people really should give it a taste.
- Komatsuna is a spring green, common in Asian markets but yet to make an appearance next to the bok choy or broccoli raab.
- Like other greens, the longer komatsuna matures, the tougher and bitterer it becomes.
- When real young, komatsuna can be eaten just like spinach, meaning it is quite tasty raw or wilted.
- Most likely, people will find komatsuna a bit more mature.
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