Unveiling sub-regional aroma differences in China's Ningxia region: Characterization of key aroma profiles and chemical foundations via sensomics and RATA

Sub-regional characteristic differentiation is crucial for development of wine regions, particularly for emerging regions. This study aims to identify and quantify the key aroma-active compounds and to analyze the aroma characteristics in Marselan wines from different Ningxia sub-regions using sensomics methods and the rate-all-that-apply approach. By employing GC × GC-qTOFMS and GC-O, we comparatively evaluated the contributions of the aroma-active compounds from four sub-regions. Fifty-three aroma-active compounds were identified. Seven compounds were important contributors to the fruity aroma. The omission experiments further confirmed the important contribution of ethyl hexanoate and β -damascenone to the floral and fruity characters. Yinchuan was characterized by its floral and fruity notes and methyl octanoate and ethyl octanoate were the main contributors. Qingtongxia and Yongning were characterized by Sweet spice , driven by nonanal and 4-methyl-1-pentanol. The differences in aroma profiles and the chemical basis across the sub-regions of Ningxia provide compelling evidence reinforcing the intra-regional micro- terroir.