Candy cap mushrooms have become a trendy food. These unusual little things taste exactly like maple syrup - to the point where the extract from them is put in cakes and ice cream. Chemists finally found out why, after over twenty-five years of research.
When they're put on menus, candy cap mushrooms tend to raise eyebrows. This is because they are typically on dessert menus. People put the extract from them in ice cream, cakes, and frosting. The practice continues because candy cap mushrooms, when dried, taste and smell exactly like maple syrup.
This puzzled Darvin DeShazer so much that he asked, William Wood, a Humboldt State University researcher, about it. He asked the question in 1985. The two worked on it, off and on, for the next twenty-seven years. Their main stumbling block was gas chromatography. This method of chemical analysis, which vaporizes compounds and allows scientists to analyze their component parts, gave samples that were too impure to be understood. Solid-phase microextraction is a technique that allows scientists to extract small samples of a compound. The technique can be used before gas chromatography, and allows for better samples. This is what helped uncover the mystery of the candy caps.
The mystery turned out to be more complicated than anyone expected. First of all, the mushroom don't give off the odor of maple syrup when fresh. Only when they dry do they start smelling sweet. The chemists determined that the amino acids in the drying mushroom combine to form quabalactone III, a chemical that is one of the many "esters." Esters are combinations of organic and inorganic chemicals that form strongly fragrant compounds. They show up in perfumes and food flavorings.
Quabalactone III isn't what smells of maple syrup. The syrup smell comes when quabalactone III combines with water to form sotolon. You eat sotolon all the time, if you eat fake maple syrup. It's one of the chemicals made by food companies and added to sugar solutions to make the fake maple syrup scorned by New Englanders. Essentially, the mushrooms are making unnatural maple syrup through natural processes.
A tiny adjustment to candy cap biology and everything could have turned out different. It's not just the presence of sotolon that makes candy caps taste and smell like maple syrup - it's the concentration. At low concentrations, sotolon smells like maple syrup. At high concentrations, it smells like curry or fenugreek. Candy caps would have been added to curries or pasta sauce recipes. We could have had mushrooms that tasted spicy, but then it's doubtful that anyone would have been curious enough about them to study them for twenty-seven years.
Top Image: James Lindsey at Ecology of Commanster
[Via The Maple Syrup Odour of the "Candy Cap" Mushroom, Humboldt State Now, Sotolon.]