Quantitative structure-activity relationships (QSAR) of aroma compounds in different aged Huangjiu

Huangjiu is a traditional wine in China with special taste and flavor. However, changes of aroma compounds during storage of Huangjiu remain unclear. In this study, aroma compounds in Jinse Nianhua Huangjiu of three different storage ages were qualitatively and quantitatively analyzed via headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). Based on odor activity value (OAV), the most important aroma compounds were found to be esters, aldehydes, alcohols, acids, ketones, phenols, and lactones. Even though the types of the aroma compounds were similar in different-aged Huangjiu, the concentrations of some compounds varied. Some aroma compounds' thresholds and OAV in Huangjiu were obtained by AC'Scent Intl. Olfactometer. It showed the key aroma compounds in Huangjiu had a positive correlation with their OAV instead of concentration. Quantitative structure-activity relationship (QSAR) models were developed to predict the flavor thresholds for alcohols, acids, and esters in Huangjiu, with higher accuracy for alcohols (R² = 0.978) and acids (R² = 0.987). This study will provide valuable information to unveil the regulation of Huangjiu flavor from molecular basis. PRACTICAL APPLICATION: The built mathematical model enables to predict changes of aroma compounds in Huangjiu during storage, based on the relationship between the quantum structure parameters of those aroma compounds and the odor activity value of flavor chemicals. This research will contribute to simplifying the wine flavor analysis for wine industry and also help to identify the age of the Huangjiu for customers.