As usual, there is a good reason the staples of Japanese cuisine endure. Amongst the gorgeous side dishes served with most Japanese meals you will almost always find a tiny dish of disks the colour of gingko leaves in the Autumn; crunchy, sweet and salty and with a delicate pepperiness that off-sets brightens up any meal.
The Japanese have been delicately pickling vegetables for centuries. Simple brines, syrups and vinegar treatments draw out moisture from the cut vegetables providing fuel and moisture for good bacteria who obligingly ferment lactic acid and contribute to a liquor that is perfect for delivering flavours, antioxidants and probiotics to aid digestion. The slightly acidic juice keeps the vegetables crisp and bitey and any spoilage micro organisms at bay. Most importantly this light fermentation treatment keeps the vegetables and their health benefits available all year round.
Known as Tsukemono, the Japanese pickle almost every type of vegetable imaginable. And types the average Westerner has never imagined – anyone care to take a guess at some of these fine specimens I photographed in Osaka’s Kuromon Market?
I like yellow, so that seemed a good enough reason to try making pickled Daikon, the mighty white radish which I coloured with a dash of turmeric. I also happened to have grown a few in my veggie patch, conveniently. Plus the Crackling Children loved the Radish Spirit Cameo in the Studio Ghibli movie Spirited Away . However, this presumed affinity still was not enough to get the youngest one to place a vegetable near his face in the end.
The magical information superhighway spat out a fabulous link to an authentic recipe over at food blog Foodjimoto, I rolled up my sleeves and cracked on with it. They turned out pretty well.
However, what interested me as much as eating them was the science behind the process the chemical and biological components of the Daikon captured in this fantastic condiment.
Like all radishes, Raphanus sativus, is highly peppery. The daikon uses the strong pepper aroma as a defence mechanism against predators such as rodents or pathogenic fungi that is to say It gives off bursts of pungent chemicals when the cell walls of the root are attacked – or chopped.
Like its close cousins the Alliums (leeks, garlic and onions) the daikon is full of organic compounds from the Glucosinolates and Isothiocyanate family. When released from the plant’s cells they mingle with the enzyme myrosinase and produce the mustard oil which hits you right between the eyes, or nostrils. This mechanism of organic compounds and enzymes mingling in attack formation also occurs Brussels sprouts and other greens that you were always told were good for you.
And the reason they are good for you, if you can get past the pepperiness is that they can inhibit the metabolism of cancer cells. Current research shows Isothiocyanates present in daikon are an established class of naturally occurring chemo preventive agents, a principal mechanism of action being to limit the generation of toxic metabolites of chemical carcinogens 1, 2. That means they inhibit the growth of cancer cells in animal models and isolated human colon cells.
Disclaimer: This does not mean they will cure individual cases of cancer on consumption and I insist that you have a look at the references if you have read this far, this isn’t the Daily Mail and I don’t put up specific health claims without reference to peer reviewed literature.
So the wisdom of the Japanese has meant that even the most meagre diet of rice and little or no protein can also provide active health benefits with the addition of a long-lasting and inexpensive, not to mention tasty, side dish. Which is fairly impressive. You don’t get that in Mc’Tucky dipping sauces, as far as I am aware.
1 . “A glucosinolate-rich extract of Japanese Daikon perturbs carcinogen-metabolizing enzyme systems in rat, being a potent inducer of hepatic glutathione S-transferase.” Abdull Razis, Ahmad Faizal ; Nicola, Gina Rosalinda ; Pagnotta, Eleonora ; Iori, Renato ; Ioannides, Costas European Journal of Nutrition, April, 2013, Vol.52(3), p.1279(7) [Peer Reviewed Journal]
2. “Kaiware Daikon (Raphanus sativus L.) extract: a naturally multipotent chemopreventive agent” Barillari, Jessica ; Iori, Renato ; Papi, Alessio ; Orlandi, Marina ; Bartolini, Giovanna ; Gabbanini, Simone ; Pedulli, Gian Franco ; Valgimigli, Luca. Journal of agricultural and food chemistry, 2008, Vol.56(17), pp.7823-30 [Peer Reviewed Journal]