枸杞鲜果贮藏期间质量损失率与时间的拟合及与质构参数的关系

Relationship between Mass Loss Percentage of Fresh Goji Berries and Either Storage Time or Texture Parameters

目的:分析常温贮藏期间去梗枸杞鲜果质量损失率随时间变化的规律及与质构参数的关系。方法:通过枸杞鲜果质量损失率散点图拟合质量损失率随时间变化;通过相关性分析寻找与质量损失率显著相关的质构参数,进而采用逐步回归法找出对质量损失率影响最显著的质构参数;通过响应面岭脊法分析质量损失率低和高时分别影响的主要质构参数。结果:常温贮藏期间,枸杞鲜果的质量损失率y随贮藏时间x以指数回归模型y=0.02319exp(x/2.69625)-0.02668增长。果实质量损失率与脆性、咀嚼性和回复性呈极显著负相关(P<0.01),而与黏着性呈极显著正相关(P<0.01)。质量损失率y与脆性x1、回复性x3和黏着性x4的逐步回归方程为y=0.4453-0.01493x1-1.2245x3+0.1148x4。响应面岭脊分析结果表明,当质量损失率低于2.55%时,随质量损失率降低,脆性和黏着性变化不明显,但回复性明显上升;当质量损失率高于56.67%时,随质量损失率增加,脆性和回复性的变化不明显,而黏着性明显增加。结论:常温贮藏期间,枸杞鲜果的质量损失率以指数模型增长,主要影响脆性、回复性和黏着性这3个质构参数,建立的数学模型可为枸杞鲜果采后贮藏时间和质构变化的预测提供理论依据。

Objective:To analyze the pattern of change in mass loss percentage and its relationship with texture parameters of fresh goji berries during storage at ambient temperature.Methods:The mass loss percentage was plotted against storage time as a scatter diagram to develop a model describing the relationship between them.Through correlation analysis,the texture parameters that are significantly related to the mass loss rate were found out,and then the ones with the most significant influence on the mass loss percentage were selected by the stepwise regression method.The main texture parameters associated with mass loss percentages lower or higher than the threshold were analyzed by response surface ridge analysis method.Results:The mass loss percentage of fresh goji berries increased with storage time,which was fitted with the exponential regression model:y=0.02319 exp(x/2.69625)-0.02668.The mass loss percentage(y)had a significantly negative correlation with brittleness(x1),chewiness(x2)and resilience(x3)(P<0.01),and a significantly positive correlation with adhesiveness(x4)(P<0.01).The following stepwise regression equation was established:y=0.4453-0.01493 x1-1.2245 x3+0.1148 x4.The results of response surface ridge analysis showed that the change in brittleness and adhesion was not obvious,while resilience increased sharply with decreasing mass loss percentage from 2.55%.As the mass loss percentage increased from 56.67%,with the increase of mass loss rate,the change in brittleness and resilience was not significant,while adhesiveness increased significantly.Conclusion:The mass loss percentage of fresh goji berries exponentially increased during ambient storage,which could mainly affect brittleness,resilience and adhesiveness.The established mathematical model in this study can provide a theoretical basis for the prediction of postharvest storage life and texture changes of fresh goji berries.