My Sushi Moment

Aug 22, 2014

Incognito attends a sushi class and ponders the plight of the analytical scientist.


Photo Credit: Skip ODonnell/Getty Images
Recently while on summer vacation I found myself taking a class on sushi making — something I'd wanted to do for several years. The class was excellent and the chef/instructor was a very amiable young man who was keen on talking about the "chemistry" of the sushi-making process — the "pickling and fermentation" of the rice, the release of starch as you patted the rice down on the Nori paper that helped to bind the rolls etc.

As we were working away, I couldn't help but notice that among some very ornate and brightly coloured tattoos which the chef sported on his forearms, there was a tattoo of what I thought I recognized as styrene. My first thought was that my new chef acquaintance had been misled and that an internet trawl for interesting sushi-based chemicals had gone badly wrong, and he would be forever doomed to be tagged with a popular monomer rather than something much more pertinent, romantic, or even illegal...one never knows!

My curiosity eventually got the better of me and in a quiet moment at the end of the class I asked the chef the relevance of his tattoo. He went on to reveal further molecules on his arms, which I've drawn out in the following figure.



There's a prize for anyone who can guess the relevance of these molecules at this stage, without reading further ahead.

Well, from left to right in the figure the molecules are acrylonitrile, 1,3-butadiene, and styrene. When polymerized they form the very common thermoplastic terpolymer, acrylonitrile butadiene styrene, more popularly known as ABS. So chef, it turns out, knew more than just a smattering of chemistry and thankfully was not labouring under a misapprehension about his indelible markings.