Horseradish – a brief review
Horseradish is a perennial plant species, a functional food, cultivated for many centuries in Eastern Hungary, and a few other places in the world. The characteristic odor makes this root an excellent spicing, its smell and taste can be linked to the presence of volatile constituents, in particular, allyl isothiocyanate and phenethyl-isothiocyanate.
The Eastern Hungarian climate is excellent for the production of high-quality horseradish products, as the warm summers and long colder periods during autumn are also necessary for proper development.
Besides being used as a food ingredient, horseradish is now under intensive research.
The main chemical constituents are glucosionaltes (thioglycosides) and isothiocyanates (volatile, essential oil constituents). The volatile constituents could be used as therapeutic agents, additives, insect repellents, and so on. Isothiocyanates are products that are not present in the root itself. They are produced from the so called glucosinolates when the plant's tissues are damaged – i.e. during processing of the root. This process requires the activity of the myrosinase enzyme in the root, making the conversion sensitive to temperature, pH, and several other factors.
Horseradish contains many other minor isothiocyanates, but the characteristic taste is attributed mainly to allyl and phenyetyl isothiocyanates. The mixture is unique to some extent, and it differentiates horseradish from mustard and wasabi.