Integrated metabolomic profiling for the identification of promising plant-based coffee substitutes

This study evaluated four plant-derived ingredients—chicory root, Jerusalem artichoke, rye, and hulled barley—as roasted coffee substitutes by comparing their physicochemical properties and metabolite compositions with those of green coffee bean. Physicochemical analyses showed that chicory root and Jerusalem artichoke exhibited titratable acidity and polyphenol levels comparable to green coffee bean. Untargeted metabolomic profiling was performed using GC-MS for non-volatile and volatile metabolites and UPLC-QTOF-MS for comprehensive metabolite coverage. Multivariate analyses indicated that chicory root and Jerusalem artichoke clustered closely with green coffee bean due to shared alkaloids and phenolic acids, whereas rye and hulled barley were characterized by higher levels of sugar alcohols and disaccharides. Integrated similarity analysis confirmed the closest resemblance for chicory root and Jerusalem artichoke, while blending all four ingredients further enhanced similarity to the coffee profile. Overall, these findings demonstrate that integrated metabolomics provides a robust framework for identifying and optimizing plant-based coffee substitutes.