Effects of different roasting temperatures on the flavor characteristics of jujube wine: Analysis based on HPLC, HS-GC-IMS, and HS-SPME-GC–MS

The effects of jujube pretreatment at different roasting temperatures (80-160 °C) on the dynamic changes in free amino acids and volatile organic compounds in jujube wine were evaluated using HPLC, HS-GC-IMS, HS-SPME-GC-MS, and sensory analysis. The results revealed that roasting at 80-100 °C enhanced the accumulation of sweet amino acids in jujube wine, whereas roasting at 140-160 °C increased the bitter amino acid content. As the roasting temperature increased, the contents of esters, alcohols, acids, aldehydes, and ketones in jujube wine rose initially before declining thereafter. Meanwhile, the furan compound content exhibited a continuous increase. Through multivariate statistical analyses, including orthogonal partial least squares-discriminant analysis (OPLS-DA), relative odor activity value (ROAV) calculations, and variable importance in projection (VIP), six key characteristic flavor compounds were identified. These included isoamyl acetate, ethyl hexanoate, and ethyl octanoate. The novel insights derived from this study could guide the improvement of jujube wine flavor.