【作者】 李霞；

【导师】 王相友；

【作者基本信息】 山东理工大学 ， 农业生物环境与能源工程， 2009， 硕士

【摘要】 气调包装（Modified Atmosphere Packaging,简称MAP）能有效地延缓果蔬的呼吸速率,抑制果蔬产品的代谢作用,从而延长其贮藏寿命和保持果蔬品质。本文针对双孢蘑菇在气调包装贮藏过程中存在的一些问题,主要进行了以下三个方面的研究:1、通过小袋法测定了不同材料薄膜分别在2℃,8℃,14℃,20℃下的薄膜透气系数,分析了温度对薄膜透气系数和透气系数比的影响。试验得出:随着温度的升高果蔬包装薄膜的透气系数增大;随着温度的上升,薄膜材料LDPE的透气系数比显著上升,但薄膜材料PVC的透气系数比在本试验温度范围内无明显变化。薄膜透气系数与绝对温度之间满足Arrhenius方程,透气系数的自然对数值与绝对温度的倒数值之间呈显著的线性关系。2、采用渗透系统法测定了15h内的包装系统内部气体体积分数值,并采用自编C语言程序拟合出双孢蘑菇在任意时刻的呼吸速率值,采用Michaelis—Menten型酶动力学方程对试验数据进行回归分析,建立了不同温度下双孢蘑菇呼吸速率随O₂、CO₂体积分数变化的数学模型,并对所得呼吸速率模型的准确性和实用性进行了验证,且根据Arrhenius方程分析了最大呼吸速率V_m与温度之间的关系。3、通过L₉（3）⁴正交试验设计,研究了不同温度、包装材料和初始O₂体积分数和CO₂体积分数对双孢蘑菇主动气调包装中贮藏保鲜效果的影响。分别于贮藏后的第3d、第5d、第7d、第9d和第11d测定各个试验处理双孢蘑菇的失重率、硬度、褐变度、呼吸速率、细胞膜透性、可溶性固形物、PPO活性和POD活性。得到了贮藏过程中能保持双孢蘑菇贮藏品质的较优处理组合,即贮藏温度为2℃、包装材料为PVC2、O₂和CO₂体积分数分别为15%和10%。更多还原

【Abstract】 Modified atmosphere packaging（MAP） is a well-established technology that can inhibits the respiration rate and metabolic activity of perishable produce, which helps in extending the shelf-life and maintenance of the quality of perishable produce.In order to solve the problems in modified atmosphere packaging of Agaricus bisporus,three parts were studied in this paper.Firstly,The gas permeability coefficients of different material films at 2、4、8 and 20℃were calculated by Small Bags Method.The influences of temperature on the gas permeability coefficient and gas permeability coefficient ratio were analyzed.The results suggested that the gas permeability coefficients of films increased with temperature;as the temperature increased the gas permeability coefficient ratio of LDPE increased significantly,while the gas permeability coefficient ratio of PVC kept stable.The relationship between permeability coefficients and temperature was well described by Arrhenius equation,and it was linear relationship between nature logarithmic of gas permeability coefficient and the reciprocal of temperature.Secondly,The package headspace composition,in terms of oxygen and carbon dioxide concentrations,in modified atmosphere package of Agricus bisporus at 2℃、4℃、8℃and 20℃respectively were monitored within 15h.The respiration rate of Agricus bisporus under modified atmosphere packaging at any instant of time were calculated by a C program based on permeable system.The dependence of respiration rate on gas composition was well described by a Michaelis Menten type equation with uncompetitive CO₂ inhibition.The model constants were estimated by fitting the model to the experimental data by non-linear regression using Excel,and the veracity and practicability of the respiration rate model were validated.The relationship between maximum rate V_m and temperature was well described by Arrhenius equation.Thirdly,A L₉（3）⁴ orthogonal test was carried out to evaluate the storage quality of Agricus bisporus under active modified atmosphere packaging with different temperature,packaging material,O₂ and CO₂ volumetric concentrations. Weight loss,fructification firmness,degree of browning,the respiration rate, membrane permeability,soluble solid content,polyphenoloxidase（PPO） and peroxidase（POD） activity of Agricus bisporus were investigated on the 3^th d,5^th d, 7^th d,9^th d,11^th d after storage,respectively.The optimum composition of active modified atmosphere packaging for Agricus bisporus was that storage temperature 2℃,packaging material PVC2,15%O₂ volumetric concentration,10%CO₂ volumetric concentration.更多还原