Horseradish: Kick ass chemistry

I like horseradish. It is used in cocktail sauce, spicy mustards, wasabi sauces and Arby's horsey sauce.

Several years ago I planted horseradish in my backyard. Horseradish is essentially a weed and grows with little attention. During October, the roots can be harvested and ground up into a most delightful condiment. I recently did that.

Here's the dirty roots:

Here they are after cleaning. One of them (top left) has been peeled:

I do everything outside so I don't die from the strong fumes. Using a food processor, I grind up the roots and add enough water to make a grindable paste. This is when the odor gets strong. To stop the enzymatic action (see below) I add a few tablespoon of a 5% aqueous acetic acid solution (vinegar) and bottle it. Here is the prepared horseradish:

Yes, I made a quart and a half. That's a lot.

So, what about the chemistry? Glad you asked.

Horseradish is not pungent until you start destroying cell walls. When that happens, enzymes are released and they go into action and start breaking down glucosinolates. The result is a number of compounds in the isothiocyanate class such as allylisothiocyanate and 2-phenyl ethyl isothiocyanate as shown:

These compounds are noxious and irritating.

But, they also have a special place in my heart. I used isothiocyanates regularly in my graduate work. I spent some time functionalizing amino terminated dendrimers with isothiocyanates. What is great about the isothiocyanate group is that it reacts exclusively with amino groups in the presence of alcohols. The isothiocyanate is tuned just right to react with the more nucleophilic N instead of the less nucleophilic O. Cool (see above and ignore the misspelled isothiocyanate).

Fire!!!!! of a different type.

Dear blog reader,

You are going to have to read "between the lines" for this post. I don't want to get googled for the wrong reasons, if you know what I mean (or at least you soon will).

Anyways, in the first organic lab of the semester, I go through a fairly extensive safety lecture. Included in that I remind them to wash their hands after every lab. I usually add, quite seriously, that they should be sure to wash their hands BEFORE they use the bathroom. What you may not feel on your hands, WILL be felt by your more sensitive areas. It is usually met with snickers, but the advice is serious albeit a bit humorous.

I need to learn to take my own advice.

I wasn't working in lab- I was making jalapeño poppers at home. My recipe is below, but it involves slitting the peppers and scraping the seeds out. I did this to 10 peppers. Then, in the vernacular of my house, I went potty. I failed to wash my hands before going.

A few minutes later... well, let me just say I wasn't happy with myself. I'm wasn't rolling on the floor in pain, but I was very uncomfortable for several minutes. It reminded me of the old "Ben-Gay in the jockstrap" practical joke. But I wasn't laughing.

After about 30 minutes the pain subsided. I had finished preparing my jalapeño poppers and had started to consume them. Man, were they good. Here's the recipe:

Filling:
4oz cream cheese
a small handful of shredded Montery Jack cheese
6 strips of chopped up and well cooked bacon
several dashes of hot sauce

The peppers are split and the seeds are removed. The peppers are filled with the filling, and then dipped in the following mixture:
1 egg
1 cup flour
enough milk to make the mixture like thin Elmer's glue

The excess is drained off and the peppers are rolled in bread crumbs (I prefer panko crumbs). They are deep fried for 2 minutes. Let cool and enjoy. Follow by a milk of magnesia chaser and loperamide HCl in the morning.

I hope you can learn from my experience. It's a bit embarrassing to tell, but it makes a good story.