Analysis of the Chemical Profile of the Essential Oil from Leaves and Cones of Four Varieties of Humulus lupulus Cultivated in a Subtropical Climate Under Edaphoclimatic Conditions

Abstract

Cultivating Humulus lupulus L. under subtropical conditions is challenging because hops are adapted to temperate climates, where environmental factors influence plant development and secondary metabolism. This study evaluated the essential oil yield and chemical composition of cones and leaves from four hop varieties (Cascade, Columbus, Comet, and Nugget) cultivated under subtropical conditions in northwestern Paraná, Brazil. Essential oils were obtained by hydrodistillation and analyzed by GC–MS. Chemical variability was investigated using Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). Cascade and Columbus showed better agronomic performance, while Nugget and Comet produced the highest essential oil yields in cones (1.532% and 0.695%, respectively). In leaves, Nugget, Cascade, and Comet exhibited the highest yields. Sesquiterpene hydrocarbons predominated in most samples, with α-humulene and β-caryophyllene as major constituents in both organs. Oxygenated sesquiterpenes, including caryophyllene oxide and humulene oxides, were also identified in the essential oils. Phytol was relatively abundant in the leaves of Cascade, Columbus, and Nugget, demonstrating differences between vegetative and reproductive tissues. PCA revealed distinct chemical patterns among varieties and harvest periods, emphasizing the influence of genotype and seasonal conditions. These results demonstrate the potential of hop cultivation under subtropical conditions and highlight leaves as a promising source of volatile compounds for further valorization and industrial applications.