基于聚类和时序分析的砂梨果实耐贮性及贮藏品质分析预测

Analysis and prediction of storability and storage quality of pear fruit based on clustering and time series analysis

目的:对3个品种砂梨的贮藏期和品质进行评价,为品种选育和保鲜技术的研发提供理论支撑。方法:以遗传背景相似的早生新水、沪晶梨18(HJ18)、沪晶梨67(HJ67)为试材,分别将成熟度一致的3个品种砂梨果实放置于温度为(1.0±0.5)℃、相对湿度85%~90%的冷库中贮藏60 d,每10 d对果实质构、糖酸及挥发性物质进行测定,基于聚类、主成分、时序分析,划分贮藏期和贮藏品质。结果:3个品种砂梨果实质地、糖酸及挥发性物质均受到贮藏时间的调控,且不同指标间有一定的相关性。可将14个品质评价参数简化为果肉组织硬度、咀嚼性、紧实度、果皮脆性、弹性、苹果酸、柠檬酸、可溶性固形物和果糖9个指标;传感器S2、S6、S7、S8、S9的贡献率较大。基于14个品质指标,贮藏期间的HJ67与早生新水和HJ18处于相对独立的空间;基于10个传感器响应值,3个品种存在空间交集,未得到有效区分。3个品种砂梨的贮藏时间被划分为不同的区间,基于质地、非挥发性和挥发性物质的划分结果较为一致,HJ67被划分为0~20,30,40~50,60 d 4个时间段。结论:HJ67质地、糖酸含量和挥发性物质与早生新水和HJ18差异显著,风味较浓郁。使用指数方程能较好地拟合3个品种砂梨果实质地的变化,非线性方程能够较好地描述糖酸含量的变化,两个预测模型的预测误差较低。

Objective:The storability and storage quality of three pear varieties were evaluated to provide theoretical support for variety breeding and fresh-keeping technology.Methods:Zaoshengxinshui,HJ18 and HJ67 pear with similar genetic background were used as test materials.Fruit with the same maturity were stored in a cold storage with a temperature of(1.0±0.5)℃and a relative humidity of 85%~90%for 60 days.The fruit texture,sugar and acid and volatile substances were determined every 10 days,divide storage period and quality based on clustering,principal components and time series analysis.Results:The results showed that the fruit texture,sugar,acid and volatile substances of the three pear varieties were regulated by storage time,and there was a certain correlation among different indexes.Fourteen quality evaluation parameters could be simplified into 8 indexes:firmness,chewiness,compactness,brittleness,elasticity,malic acid,citric acid,soluble solids content(SSC)and fructose.The contribution rate of sensors S2,6,7,8 and 9 was larger.Based on fourteen quality indexes,HJ67 was in a relatively independent space with Zaosheng Xinshui and HJ18 during storage.Based on the response values of ten sensors,the three varieties had spatial intersection,which had not been effectively distinguished.The storage time of three pear varieties was divided into different intervals,among which HJ67 was divided into four periods:0~20 days,30 days,40~50 days and 60 days based on texture,nonvolatile and volatile substances.Conclusion:It is concluded that the texture,sugars and acids contents and volatile matter of HJ67 are significantly different from those of Zaoshengxinshui and HJ18,that has a rich flavor.The change of fruit texture of three pear varieties can be well fitted by exponential equation,and the change of sugar and acid content can be well described by nonlinear equation.The prediction errors of the two prediction models are low.Based on principal component analysis,cluster analysis and time series analysis,the storage period and comprehensive quality of three pear varieties can be comprehensively and objectively evaluated.