Chemical and flavour dynamics in Cyperus esculentus L. pomace-raspberry composite fruit wine fermentation: A combined UHPLC-OE-MS and HS-SPME-GC–MS approach

To increase the flavour complexity and overall quality of pure raspberry fruit wine, a novel composite fruit wine was developed using <i>Cyperus esculentus</i> meal saccharification liquid and red raspberries as raw materials. In this study, ultrahigh-performance liquid chromatography with online extraction and mass spectrometry (UHPLC-OE-MS), as well as headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), were used to investigate the impact of raspberry saccharification liquid on the chemical composition and flavour profile of the composite fruit wine. The findings are summarized as follows: Significant differences were observed in the composition of sugars, amino acids, and fatty acids between the composite fruit wine and pure raspberry wine. Notable increases were detected in nonanedioic acid, chlorogenic acid, D-tartaric acid, and gluconic acid. Additionally, substantial increases were detected in the levels of esters, terpenes, alcohols, acids, aldehydes, and ketones, including unique compounds such as decanoic acid ethyl ester, 2,3-dehydro-1,8-eucalyptol, and absynthin, as well as cyclohexanol,1-methyl-4-(1-methylbutyl)-trans-1,5-heptadiene-4-one, and 3,3,6-trimethylhexanoic acid. In contrast, the concentrations of compounds such as succinic acid, propanal, 4-hydroxyproline, and ethyl acetate significantly decreased. This modification increased various aromatic compounds, enriching the flavour profile of the fruit wine and enhancing its complexity and overall aromatic characteristics. The findings of this study provide valuable insights for the development of high-quality composite fruit wines.