A research team has solved the mystery of a novel clove-like off-flavor in orange juice, the cause of which was previously unknown. The study proves for the first time that the undesirable flavor note is due to the odorant 5-vinylguaiacol. As the results of the study show, the substance is mainly produced during the pasteurization process when residues of a cleaning agent react with a natural orange juice component under the influence of heat.