Black garlic has been appreciated in Asia for several hundred years for its health benefits. But beyond its vertues, black garlic brings a range of flavors quite different from fresh garlic. A Chinese research team in food science looked into the aromatic compounds of black garlic to establish, with high-tech tools, what made black garlic so unique in terms of its aromas. Using a technique to separate the molecules of black garlic and identify them by measuring their mass and chemical structure, the authors listed 52 aromatic compounds with their relative importance. They then repeated the same analysis with fresh garlic.
Among the heterocyclic aromatic compounds, namely when the cycle contains something other than carbon and hydrogen, the authors have identified caramel, balsamic, roasted nuts and apricot aromas. A certain amount of acetic acid was also detected, explaining its slightly vinegary side.
With more complex and more diverse aromas than of fresh garlic, it is the transformation undergone by black garlic that allows it to reach this unique and complete flavor.
Yang P, Song H, Wang L, Jing H. Characterization of Key Aroma-Active Compounds in Black Garlic by Sensory-Directed Flavor Analysis. J Agric Food Chem. 2019 Jul 17;67(28):7926-7934. doi: 10.1021/acs.jafc.9b03269