To discriminate the aroma-active compounds in dried jujube slices through microwave-dried treatments and understand their sensory attributes, odor activity value (OAV) and detection frequency analysis (DFA) combined with sensory analysis and analyzed through partial least squares regression analysis (PLSR) were used collaboratively. A total of 21 major aromatic active compounds were identified, among which 4-hexanolide, 4-cyclopentene-1,3-dione, 5-methyl-2(5H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)furanone, 3,5-dihydroxy-2-methyl-4-pyrone were first confirmed as aromatic compounds of jujube. Sensory evaluation revealed that the major characteristic aromas of dried jujube slices were caramel flavor, roasted sweet flavor, and bitter and burnt flavors. The PLSR results showed that certain compounds were related to specific taste attributes. 2,3-butanedione and acetoin had a significant positive correlation with the roasted sweet attribute. On the other hand, γ-butyrolactone, 4-cyclopentene-1,3-dione, and 4-hydroxy-2,5-dimethyl-3(2H)furanone had a significant positive impact on the caramel attributes. For the bitter attribute, 2-acetylfuran and 5-methyl-2(5H)-furanone were positively correlated. Regarding the burnt flavor, 5-methyl-2-furancarboxaldehyde and 3,5-dihydroxy-2-methyl-4-pyrone were the most influential odor-active compounds. Finally, 2-furanmethanol and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one were identified as the primary sources of the burnt and bitter flavors. Importantly, this work could provide a theoretical basis for aroma control during dried jujube slices processing.

For the winemaking bioprocess of jujube wine, the selection of optimal starter cultures is one of the major concerns before fermentation. In this study, we investigated the effects of different winemaking yeasts on the composition of aroma-active compounds in the fermented jujube wine and identified the principal components that determine the flavor quality. It showed that the starter winemaking yeasts produced a total of 43 aroma-active compounds, of which esters (e.g., ethyl caprylate, ethyl decanoate, ethyl hexanoate, and phenethyl acetate) contribute more to the wine quality attributes, especially for the improvement of the aroma. Moreover, the composition of aroma-active compounds, for example, the ratio of the content of esters and alcohols, exerts a great impact on the flavor quality of jujube wine. Different starter winemaking yeasts resulted in significant differences in the composition (both species and content) of aroma-active compounds, and thus formed different flavors in the jujube wine. Thus, we propose that screening of a desirable starter winemaking yeast is essential before the fermentation of jujube wine at a large scale, and more considerations should be taken into the resulting composition of aroma-active compounds.

Grey jujube (Zizyphus jujuba Mill. cv. Huizao), a prominent cultivar from Xinjiang, China, is well known for its high nutritional value and medicinal benefits. This study investigates the effects of long-term storage on the quality attributes of grey jujube, focusing on color, texture, physicochemical properties, bioactive ingredients, amino acid profiles, sensory characteristics, and volatile compounds. Over a three-year storage period, significant changes were observed, including a decline in lightness and redness of the peel, accompanied by textural modifications such as increased hardness and chewiness, primarily attributed to moisture loss. Physicochemical analyses revealed significant reductions in moisture content, sugars (particularly reducing sugars), and bioactive compounds such as vitamin C, total flavonoids, and cyclic adenosine monophosphate (cAMP). In contrast, total acidity showed a significant increase over time. Sensory evaluation indicated a substantial loss of fresh aroma and flavor, with the development of off-flavors over time. Additionally, a comprehensive analysis of volatile compounds highlighted significant transformations in aroma profiles, with notable reductions in desirable esters and increases in acetic acid concentrations. This study investigates the quality changes of grey jujubes during storage from sensory and physicochemical perspectives, aiming to provide a novel approach for differentiating between newly harvested and aged grey jujubes. Furthermore, these findings provide theoretical support for improving and optimizing storage conditions. Future research should focus on elucidating the underlying mechanisms of these changes, identifying key markers for quality control during grey jujube storage, and providing a scientific basis for distinguishing between newly harvested and aged grey jujubes, while improving storage quality.

Newhall navel oranges show distinct quality differences across major producing regions in China but their specific quality characteristics remain unclear. This study compared their sensory, nutritional, and flavor properties, and investigated environmental effects and related underlying mechanisms. The results showed that Newhall navel oranges from Xinfeng, Jiangxi Province, achieved the highest overall sensory score, characterized by high sucrose content, richer aroma, and greater consumer preference. In contrast, those from Zigui, Hubei Province, exhibited higher acidity alongside greater levels of functional components (ascorbic acid, hesperidin, β-carotene). Further analysis identified (E)-2-hexenal, ethyl butanoate, octanal-D, hexanal-D, ethyl acetate, and pentan-2-one as differential aroma markers across producing regions. Hesperidin and ascorbic acid were significantly positively correlated with altitude but negatively correlated with temperature and light time, whereas sucrose content showed a negative correlatedion with altitude. Variations in the fruit quality of Newhall navel oranges were significantly correlated with climatic conditions: higher altitude and lower temperature may be associated with elevated ascorbic acid contents, while greater precipitation may correlate with reduced sugar concentrations. This study provides indirect evidence for the influence of geographical regions and environmental factors on the quality differences of Newhall navel oranges.