Essential oils: old data, new applications, and direct profiling methods

Essential oils (EOs) are liquid preparations obtained from aromatic plants, herbs, and spices that contain a complex mixture of low-molecular-weight compounds in different concentrations and a wide variety of biological activities. EOs have been known since the Middle Ages and are used for their biological potential that goes beyond their use as medicinal elements, aromatherapy, and primary food preservation to new applications in the pharmaceutical, agricultural, food, and art industries. The chapter aims to review and compare the obtaining, trade management, and use of EOs for the benefit of health during the 16th and 19th centuries in contrast to their use and new applications in the present century. In addition, an exploration and description of direct methods for characterizing the profile of EOs are carried out. The chapter provides the evolution of EOs from colonial times to the present day with respect to their use as health promoters, management, and characterization.