[目的]探究不同成熟度鲜枣的冰点温度及其与主要理化性状之间的关系.[方法]以鲜食枣品种'冬枣'和'月光'为试验材料,利用testo175-T2 电子温度记录仪测定其冰点温度,并且测定鲜枣单果质量、体积、密度及可溶性固形物含量等指标.利用灰色关联度分析法及Origin软件对可能影响鲜枣果实冰点温度的相关因素进行分析.[结果]不同品种及不同成熟度鲜枣的冰点温度存在显著差异,随着鲜枣成熟度的增加,果实的冰点温度逐渐降低,且果实越小,降低到冰点温度所需时间越短;'冬枣'和'月光'白熟期的冰点温度分别为-3.5℃和-3.3℃,而全红期的冰点温度分别为-6.5℃和-7.6℃;后续将冰点温度与所测定的指标进行灰色关联度分析,得出可溶性固形物含量对鲜枣果实冰点温度的影响最大,而单果质量和果实体积对冰点温度的影响最小;据此进行相关性分析得出可溶性固形物含量与冰点温度呈显著负相关关系,随后根据二者的负相关关系建立了可溶性固形物含量与冰点温度的线性回归方程:y=-0.283 2 x+1.654 9.[结论]随着鲜枣成熟度的增加,其冰点温度逐渐降低,且果实冰点温度与可溶性固形物含量呈显著负相关关系,即可溶性固形物含量越高,其冰点温度越低,利用可溶性固形物含量来准确预测果实的冰点温度,可用来指导鲜枣的冰温贮藏.
[Objective]The research aims to explore freezing point temperature of fresh jujube fruit with different maturity and the main physical and chemical characteristics.[Method]The two different varieties'Dongzao'and'Yueguang'were used as the experimental materials to determine the freezing point temperature using a testo175-T2 electronic temperature recorder,and the single fruit mass,volume,density and soluble solid content were measured.The relationships were analyzed using the gray correlation analysis and Origin software.[Result]The freezing point temperature varied between the two jujube varieties with different maturities.As the maturity of fresh jujube fruit increased,the freezing point temperature decreased.The smaller the fruit,the shorter time it took to drop down to the freezing point temperature;The freezing point temperature of'Dongzao'and'Yueguang'at white maturity was-3.5℃and-3.3℃,the freezing point temperature at full red was-6.5℃and-7.6℃.The gray correlation analysis indicated that the soluble solids content had the greatest effect on the freezing point temperature,followed by the mass and volume of the fruit.Correlation analysis was conducted,revealing a significant negative correlation between the soluble solids content and freezing point temperature.A regression equation for soluble solids content and freezing point temperature was established based on the correlation:y=-0.283 2 x+1.654 9.[Conclusion]As the maturity of jujube fruit increases,the freezing point temperature decreases.The freezing point temperature and soluble solids content are negative correlation.In other words,as the soluble solids content increases,the freezing point temperature decreases.The soluble solids content can be used to accurately predict the freezing point temperature,which will guide the controlled freezing-point storage of postharvest jujube fruit.