Phytochemical Profiling of Brazilian-Grown Comet Hops Revealed by GC×GC-MS and UHPLC-MS/MS and Antioxidant Activity Assessment Supported by in Silico Prediction

Comet is a hop (Humulus lupulus L.) variety with expanding cultivation in Brazil due to its high productivity, citrus aroma, and high α-acid content, characteristics particularly appreciated by the brewing industry and craft beer producers. Despite its good adaptability under Brazilian conditions, the chemical composition of Comet hops requires further investigation to elucidate the influence of regional edaphoclimatic variability on both volatile and non-volatile constituents. The chemical profile of this hop variety was investigated by analyzing Comet hops cultivated in São Paulo State during the 2024 and 2025 crop years using GC×GC−MS/FID for essential oils and UHPLC−MS/MS for ethanolic extracts. In addition, total α- and β-acids, total phenolic content, and antioxidant activity were determined, while the antioxidant potential of identified compounds was predicted in silico (Pa). Essential oil yields (2.09 and 2.22 g·100 g−1 for 2024 and 2025, respectively) were higher than those reported in the literature for the same variety grown in other regions. The predominant substances were β-myrcene, (E)-caryophyllene, α- and β-selinene, and (E)-β-ocimene, which showed quantitative interannual variation likely associated with plant adaptive mechanisms, possibly influenced by increased rainfall in 2025. Ethanolic extracts showed the presence of cohumulone, humulone, lupulone, and colupulone, along with 19 additional annotated compounds, including phenolics such as quercitrin and quercetin, with no qualitative differences between crop years. Total bitter acid content was 8.6% and 10.5% for α-acids and 1.4% and 1.2% for β-acids in 2024 and 2025, respectively. In silico analyses predicted a higher probability of antioxidant-related activity for bitter acids and phenolic compounds, whereas essential oil constituents showed lower predicted activity. The Comet variety demonstrated strong adaptability to subtropical conditions, maintaining a consistent chemical profile for both essential oil and extracts across harvest years. This study provides the first comprehensive chemical characterization of Comet hops cultivated in Brazil and highlights their richness and potential for brewing, pharmaceutical, cosmetic, and functional food applications.