A combined untargeted and targeted approach was established for fingerprinting volatile organic compounds in winter jujubes from eight regions of China. Volatiles, including alcohols, aldehydes, acids, esters, and alkenes, were identified by gas chromatography-ion mobility spectrometry (GC-IMS). Benzyl alcohol, octanoic acid, 2-hexenal, linalool, 2-nonenal, and ethyl decanoate were the most common compounds present in all jujubes. Principal component analysis (PCA) from GC-IMS and untargeted E-nose showed that the main volatile organic compounds (VOCs) of most jujubes were similar. The volatile organic compounds of winter jujubes from Yuncheng city, Shanxi province, and Aksu region, Xinjiang province, were significantly different from those from other regions. 1-Penten-3-ol, ethyl hexanoate, methyl laurate, and 2-formyltoluene were the markers of XJAKS with green and fruity aroma, and SXYC could be labeled by acetone and 2-methoxyphenol with woody and pungent aroma. GC-IMS was an effective method for volatile fingerprinting of jujubes with high sensitivity and accuracy.

The aroma characteristics of six red jujube cultivars (Jinchang—‘JC’, Junzao—‘JZ’, Huizao—‘HZ’, Qiyuexian—‘QYX’, Hetiandazao—‘HTDZ’, and Yuanzao—‘YZ’), cultivated in Xinjiang Province, China, were studied by E-nose and GC-IMS. The presence of acetoin, E-2-hexanol, hexanal, acetic acid, and ethyl acetate played an important role in the classification results. JC, JZ, HZ, and YZ were different from others, while QYX and HTDZ were similar to each other. HZ had the most abundant specific VOCs, including linalool, nonanoic acid, methyl myristoleate, 2-acetylfuran, 1-octen-3-one, E-2-heptenal, 2-heptenone, 7-octenoic acid, and 2-pentanone. HZ had higher intensity in jujube ID, floral, sweet, and fruity attributes. Correlation analysis showed that jujube ID (identity) might be related to phenylacetaldehyde and isobutanoic acid that formed by the transamination or dehydrogenation of amino acids; meanwhile, the sweet attribute was correlated with amino acids, including threonine, glutamic acid, glycine, alanine, valine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine.

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.

Co-fermentation with Saccharomyces cerevisiae and selected non-Saccharomyces yeasts is an effective approach for producing fruit wines with distinctive aromas. This study aimed to improve the aroma complexity of jujube wine by evaluating multi-strain sequential inoculation strategies. Two indigenous non-Saccharomyces strains, Hanseniaspora uvarum TD74 and Metschnikowia pulcherrima HJ79, were sequentially inoculated for fermentation in combination with S. cerevisiae. The physicochemical properties and volatile compound profiles of jujube wines produced under different inoculation conditions were analyzed using HS-SPME-GC–MS, coupled with electronic nose, electronic tongue, and chemometric analyses. Compared with single-strain fermentation, sequential inoculation with the two non-Saccharomyces yeasts produced significantly more distinct volatile profiles. In particular, the triple-strain sequential inoculation group (MHS) exhibited higher semi-quantitative levels of most ethyl esters, with a more pronounced fruity aroma in the wine, consistent with the results of sensory analysis. These findings demonstrated that the use of multiple non-Saccharomyces yeasts is an effective strategy for enhancing the aromatic diversity and overall sensory quality of jujube wine, offering a theoretical basis for the rational design of optimized starter cultures for industrial jujube wine production.