The effect of cold plasma treatment on the fruit quality and aroma components of winter jujubes ( Ziziphus jujuba Mill. ‘Dongzao’)

Cold plasma (CP) is a novel environmental-friendly preservation technology that causes minimal damage to fruits. The flavor and quality of winter jujubes have decreased with the extended storage time. Currently, the research on the use of CP on winter jujubes (Ziziphus jujuba Mill. 'Dongzao') mainly focuses on the effect of the treatment on storage quality. There is limited research on the effect of CP treatment on the flavor of winter jujubes. This study used different CP (80 kV) treatment durations (0, 5, and 10 min) to treat winter jujubes. The appropriate treatment time was selected by observing the changes in color, respiratory intensity, soluble sugar content, total acid content, and vitamin C (VC) content of winter jujubes. Amino acid analyzer and headspace solid-phase microextraction in combination with gas chromatography coupled with mass spectrometric detection were used to analyze the effect of CP treatment on the flavor compounds of winter jujubes. The results showed that the 5-min CP treatment could significantly slow down the red coloration of winter jujube while maintaining high soluble sugar, total acid, and VC content. At the respiration peak, the respiratory intensity of the 5-min CP treatment group was 0.74 mg CO₂·kg^-1·h^-1 lower than that of the control group (p < 0.05). CP treatment slowed down the decrease in the content of amino acids and volatile organic compounds (such as 2-methyl-4-pentenal, 2-hexenal, and 3-hexenal) in winter jujubes. This study will provide basic data for applying CP preservation technology in postharvest winter jujubes.