Prediction of compounds affecting makgeolli aroma through multivariate analysis

This study aimed to identify the key volatile compounds and their contributions to the sensory characteristics of commercial makgeolli. Quantitative descriptive analysis of six makgeolli samples revealed ten sensory attributes (eight aroma and two taste attributes), with significant differences among samples. Notably, samples using different traditional nuruk showed distinct characteristics: some exhibited strong fermented and acidic notes, while others demonstrated predominant fruit notes, highlighting the crucial role of nuruk quality in determining sensory properties. Gas chromatography-mass spectrometry (GC-MS) analysis identified 43 volatile compounds, with 13 compounds commonly present across samples. Gas chromatography-olfactometry (GC-O) analysis revealed 38 aroma-active compounds, among which isoamyl alcohol, ethyl caprate, methionol, and 2-phenylethanol were identified as fundamental aroma compounds through both GC-O and odor activity values (OAVs) analyses. Correlation analysis demonstrated significant relationships between volatile compounds and sensory characteristics: isoamyl alcohol strongly correlated with alcohol and banana-like notes (r>0.90), while methional showed strong association with nuruk-like aroma (r=0.908). Notably, phenylethanol exhibited high values in instrumental analyses and was characterized by rose notes in GC-O; however, these characteristics were not distinctly perceived in sensory evaluation, suggesting masking effects in the complex matrix. This comprehensive analytical approach provides insights into the relationship between volatile compounds and sensory characteristics of makgeolli, emphasizing the importance of systematic quality evaluation in makgeolli.