Enter the Daikon (Raphanus sativa):
It’s still winter outside and, because of this, I decided to write our very first Weekend Variety post on daikon. This radish, one of our favorite vegetables, stores great in winter. They stay so well that some dub them the “icicle radish” or the “winter radish.” But not even knowing these names, and just by looking at a them, you can tell that daikons are hardier than the rest of the radish tribe. For one, daikons are monstrously big, giants really, like Godzilla walking among the people of Tokyo. Other radishes are puny in comparison.
Daikons are so hardy that the Japanese harvest some varieties right out of the snow. They call these radishes Yukinoshita Daikon. This Japanese TV show claims that the Yukinoshita daikon “tastes just like pears [with an]; enhanced sweetness and soft texture.” Sounds delicious.
The daikon is an annual in the Mustard family (Brassicaceae). It is a versatile crop that can grow in almost all regions of the world. Its flowers, like all radish flowers, are in the form of an “x” with four petals and four sepals. When the plant matures, it has deeply lobed leaves and bean-like seedpods that travel upward, radiating around a central stem.
Culture and Use:
Primarily, the daikon is eaten in Asia, where all radishes are thought to originate. In North America, we typically use its giant root bulk to break up soils or prevent compaction by growing them in fields that are fallow. Up until recently, for most of us in the states, daikons have been fodder, not food. We fed it to our animals but not us. But now, even in the states that’s changing. More and more people are learning how to cook and eat it.
Daikons have a sweeter more mild taste than most radishes, but that too depends upon how it’s grown, when it’s harvested, and how it’s prepared. We like daikons in our sandwiches and also like to eat them right out of the ground. Apparently, the most common way for the Japanese to eat the daikon is as a finely chopped condiment. Finely chopping the daikon increases enzymatic activity in the plant and gives an excuse to add it to all kinds of dishes, which the Japanese do, of course.
We planted daikon last year with great success. As with other radishes, the daikon grows well in upset soil but it does take longer to grow to full size than most. Usually, you plant in the early summer and harvest late fall. In future years, we would like to try planting the daikon as a more extensive cover crop that we would allow to die off in the winter, followed by a crop of perennial tubers like Jerusalem Artichokes in the spring. Daikons are used to aerate the soil, adding biomass deep into the sub-soil through their massive root system, and as a bio-accumulator, holding onto the soil’s nitrogen and preventing it from leaching. This would give a boost to our chokes and we could pick some of the daikon as well, giving us a needed boost too.
Daikon’s leaves and roots are high in vitamin C, 25% the recommended value per serving. It is also a good source of digestive enzymes.
In daikon, as in many plants, the chemicals used to ward off predators are the ones beneficial to us. Daikon contains an enzyme called Myrosinase which, when the plant is damaged, mixes with other chemicals in the radish to produce the anti-cancer chemical sulphoraphene. Ironically, this same reaction between myrosinase and other chemicals within the radish and other mustards also produces goitrogens, which can inhibit iodine uptake, and nitriles which can also be toxic to humans. Some say that these toxins are in such a minute amount that it really is no concern. But for sensitive individuals, it might be something to think about.
One of the great things, about eating with diversity and variety, is that there’s so much food, we’re probably not going to consume food in the mustard family all the time, let alone the humble, daikon radish. While one meal we might have an iodine inhibiting radish, the next meal we might have a bunch of kelp that is chock full of iodine. We get rich on the radish anti-cancer compounds, we get rich in iodine. Nature tends to balance life in diversity.
There’s also a great amount of diversity in storage and preparation of different foods which heighten or lessen different chemicals in the plant. Myrosinase, for example, is heat sensitive, so if you cook the daikon at high temperatures, you’re probably not going to get the good effects or the bad effects. Similarly, heat destroys the oxalic acid in spinach and, when cooked immediately, the beneficial allicin in garlic.
Even combinations of foods can change the chemical nature of things. Research shows that frozen broccoli, blanched before packing, no longer contains myrosinase, because the high temperatures destroy it. But if you add just a little bit of raw daikon to thawed frozen brocolli, then the myrosinase in the daikon reacts to the chemicals in the brocolli and behold, anti-cancer compounds are created! Daikon is magic.
Stay tuned this week we’re going to have a Japanese pickling adventure for you, featuring the daikon among other vegetables.
Leave a comment down below and tell us your experience with this giant radish. Or, if you want, read more of our Japanese food posts here.
Elpel, Thomas J. Botany in a Day. 5thth ed., Pony, MT, Hops Press, LLC, 2004, pp. 86-87