10.1021/acs.jafc.0c01479.s001 Sichaya Sittipod Sichaya Sittipod Eric Schwartz Eric Schwartz Laurianne Paravisini Laurianne Paravisini Edisson Tello Edisson Tello Devin G. Peterson Devin G. Peterson Identification of Compounds that Negatively Impact Coffee Flavor Quality Using Untargeted Liquid Chromatography/Mass Spectrometry Analysis American Chemical Society 2020 kauren -19-oic acid High-resolution mass spectrometry cup score specialty coffee brew SCA quality graders 16α- hydroxy -17- ent kaurane diterpene compounds Specialty Coffee Association kauran -19-oic acid LC Negatively Impact Coffee Flavor Quality 2020-03-25 23:29:18 Journal contribution https://acs.figshare.com/articles/journal_contribution/Identification_of_Compounds_that_Negatively_Impact_Coffee_Flavor_Quality_Using_Untargeted_Liquid_Chromatography_Mass_Spectrometry_Analysis/12032628 Untargeted liquid chromatography/mass spectrometry (LC/MS) flavoromics analysis was carried out on 18 coffee brews ranging in Specialty Coffee Association (SCA) cup scores. Six compounds highly predictive of low cup score were isolated from coffee using multidimensional preparative LC/MS and further evaluated by sensory recombination analysis with certified SCA quality graders. A significant decrease in cup score was demonstrated with four of the six compounds when added to a specialty coffee brew. High-resolution mass spectrometry and mono- and bidimensional nuclear magnetic resonance experiments were used to successfully elucidate four of the structures as 16α,17-dihydroxy-<i>ent</i>-kauran-19-oic acid (compound <b>1</b>), its diglycosidic compound 16α,17-dihydroxy-<i>ent</i>-kauran-19-diglycoside (compound <b>2</b>), 16α,17,18-trihydroxy-<i>ent</i>-kauran-19-oic acid (compound <b>5</b>), and 16α-hydroxy-17-<i>ent</i>-kauren-19-oic acid (compound <b>6</b>). All four <i>ent</i>-kaurane diterpene compounds were endogenous to green coffee beans, providing direct chemical indicators of low-quality coffee.