Key Aroma Compounds and Their Interactions in Maopu Herbal Baijiu

Aroma extract dilution analysis (AEDA) was employed to detect the aroma-active compounds of Maopu herbal Baijiu. The aroma-active compounds with FD≥2 were quantified through liquid-liquid extraction and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (GC-MS). The characteristic compounds were investigated via their FD values, aroma activity values (OAVs), and aroma recombination experiment. The interactions among these compounds were then investigated using the Feller additive model and S-curve. The result showed that a total of 84 aroma-active compounds were identified, mainly esters, acids, aldehydes, and terpenes. Significant differences were distinguished in the content of aroma compounds of the three herbal Baijiu (P<0.05). Furthermore, a total of 51, 53, and 54 compounds with OAV≥1 were confirmed as important aroma compounds in the three herbal Baijiu, respectively. The result revealed that ethyl hexanoate and ethyl butanoate played critical roles in the overall aroma characteristics. In addition, 3-methylbutanal, butanoic acid, hexanoic acid, ethyl 3-methylbutanoate, ethyl 2-methylpropanoate, ethyl 2-methylbutanoate, dimethyl trisulphide, and 1,1-diethoxyethane also significantly contributed to the aroma characteristics. Further experimental results showed interactions between different compounds, including masking, addition, and synergism. For example, a masking effect occurs between ethyl hexanoate and dimethyl trisulfide, an additive effect occurs between ethyl hexanoate and ethyl 3-methylbutyrate, and a synergistic effect occurs between ethyl 3-methylbutyrate and hexanoic acid. The findings of this study can offer theoretical foundations and data-driven references for product design, flavor reconstruction, and quality enhancement in the herbal Baijiu industry.