Unravelling the key flavor components of beer based on a new online recombination olfactometry of mixed targeted compounds.

Molecular sensory science provides a powerful methodology to uncover the relationships between chemical components and sensory attributes, identify key aroma compounds and develop food flavor profiles. However, this approach is labor-intensive and resource-demanding due to the need for off-line aroma extraction, dilution and recombination tests using standard references. This complexity causes unsatisfactory recombination results, particularly when identifying certain compounds is challenging. In this study, we developed a novel method for online recombination olfactometry of mixed targeted compounds using gas chromatography-quadrupole time-of-flight mass spectrometry. For the first time, it was applied to analyze the aroma-active components of a lager beer. Our analysis identified key aroma-active components that distinguish this beer from others, including nerol, geraniol, 2-pentadecanone, ethyl 3-phenylpropionate and γ-octanolactone. These findings provide a scientific foundation for constructing a molecular sensory beer map and facilitate flavor modulation, while also offering innovative perspectives and analytical tools for advancing molecular sensory assessment technologies.