Hop Essential Oils: Multivariate Hydrodistillation Optimization and GC-MS Characterization

Hop essential oil (EO) play a key role in beer aroma and quality control. In this study, a simplified hydrodistillation method for hop EO extraction using a Box-Behnken design was optimized, varying hop mass, water volume and distillation time. Terpenes─myrcene, β-caryophyllene and β-farnesene─were quantified by GC-MS. Initial results demonstrated that EO yield increased with lower hop mass and longer distillation time, while myrcene extraction was favored by shorter times. Optimal conditions (0.9 g hops, 75 mL water, 60 min) were applied to extract and qualitatively analyze EOs from Polaris, Perle, Ariana, and Hallertauer Magnum hops. Perle and Magnum exhibited typical terpene profiles but elevated β-farnesene levels and distinctive minor compounds. Ariana exhibited weak terpene signals but revealed uncommon esters. Overall, the method proved effective and resource-efficient, providing a practical tool for terpene profiling in underexplored hop varieties and supporting aroma characterization in the brewing industry.