【作者】 高松；

【导师】 王志伟；

【作者基本信息】 江南大学 ， 包装工程， 2014， 博士

【摘要】 包装油墨中的有毒有害物质可通过迁移进入内装食品从而危害人体健康。增塑剂（塑化剂）是油墨中所必需的助剂，近来邻苯二甲酸酯类增塑剂所引起的食品安全问题得到人们越来越广泛的关注和重视。论文就纸包装油墨中增塑剂的迁移问题进行了系统研究，建立了纸张真实油墨中污染物的迁移预测模型，实验得出了油墨中增塑剂向食品及食品模拟物的迁移行为，主要内容包括：（1）迁移预测模型的建立结合油墨在纸张中的渗透，基于Fick扩散建立了纸包装油墨中污染物的迁移模型。模型将印张分为油墨层和纸张层，初始时刻纸张层的污染物浓度成梯度分布，并在食品－纸张界面考虑传质系数hm和分配系数KF,P。通过分离变量法求得了模型的解析解，讨论了油墨渗透深度L1、污染物初始浓度CP0、污染物在纸张内的扩散系数DP、传质系数和分配系数、纸张厚度L2（或L3）对迁移行为的影响。（2）纸包装油墨中增塑剂的迁移实验研究选定油墨中使用较广泛的邻苯二甲酸酯类增塑剂邻苯二甲酸二（2-乙基己基）酯（DEHP）、邻苯二甲酸二丁酯（DBP）、邻苯二甲酸二正辛酯（DOP）以及近年来提倡的环保增塑剂乙酰柠檬酸三丁酯（ATBC）为研究对象，建立了奶粉、食品模拟物Tenax（改良聚苯醚，MPPO）及纸张油墨中增塑剂的乙醇溶液振荡及超声的提取方法及GC-FID（气相色谱－氢火焰离子化检测器，gas chromatography-flame ionization detection）检测条件，提出了适于迁移的真实油墨样张的实验室制备方法，实验研究了25、50、70和100℃下纸张真实油墨中四种增塑剂向Tenax和奶粉的迁移，讨论了纸张克重、油墨初始量、温度、增塑剂分子量及分子结构等因素对迁移行为的影响。结果表明前处理方法成本低、环保且回收率在71.2~113.4%之间，检测方法能在13分钟内一次性检测四种增塑剂且相互分离度在1分钟左右，印制后的样张中增塑剂含量均匀，相对标准偏差在1.1~5.9%之间，迁移结果显示Tenax中增塑剂的最大迁移量为21.3~59.2%，奶粉中的最大迁移量在6.7~67.8%之间。在此基础上，实验研究了微波条件下纸包装油墨中增塑剂的迁移。以实际使用条件为基础，分别考查了100、250、440、600和900瓦(W)五个功率下四种增塑剂向Tenax和奶粉的迁移，讨论了迁移影响因素并与常规条件下的迁移结果进行比较。结果显示，微波功率及迁移时间、增塑剂与纸张的亲疏性、食品特性等因素均影响迁移行为，微波加热条件下增塑剂比常规加热条件下更易于在短时间内发生迁移。（3）迁移预测模型的有效性及实验值与预测值的对比分析简化后的单层模型与经典的考虑传质系数的Crank扩散模型的结果相同，验证了迁移模型的有效性，并将模型简化为单层模型及双层模型时分别与实验数据进行比较验证，进一步讨论了预测模型的通用性。选定DBP，根据实验参数和结果，通过迁移模型拟合出50℃、70℃和100℃的传质系数和扩散系数，得出它们的对数值与温度接近线性关系。将拟合得到的传质系数和扩散系数用于不同初始浓度的迁移行为的预测，也插值计算出其它温度的传质系数和扩散系数用于模型预测，并与实验值进行比较。结果表明模型预测值与实验值较吻合。扩散系数的经验公式不能反映分子极性对迁移行为的影响，可选取合适的传质系数来提高DEHP、DOP和ATBC的预测精度。更多还原

【Abstract】 Packaging inks contain toxic and hazardous substances migrating into food thereby endangeringhuman health. Plasticizers are indispensible additives in inks. Phthalate plasticizers recently arousedmore and more attention among people due to its food safety issues.In this paper, the migration of plasticizers from paper packaging inks was studiedsystematically. The model of migration from real inks on paper packaging was developed.The kinetic migration of plasticizers in inks to food and food simulants was studied byexperiments. This paper mainly contains the following content.Migration modelingThe mathematical migration model of contaminants from paper packaging inks wasdeveloped based on Fickian diffusion combined with penetration of inks into paper. In thismodel, the printed paper was treated as a two-layer system containing the ink layer and thepaper layer. The initial concentration of the contaminants in paper layer followed the gradientdistribution. Mass transfer coefficient hmand partition coefficient KF,Pat the interface of paperand food were introduced. The analytical solution of the model was obtained by separation ofvariables method. The migration influencing parameter such as the ink penetration depth L1, theinitial concentration of pollutants CP0, diffusion coefficient of pollutants within the paper DP,the mass transfer coefficient, the partition coefficient and paper thickness L2(L3) werediscussed.Migration test of plasticizers from paper packaging inksThe plasticizers investigated in real inks included commonly used dibutyl phthalate (DBP),bis(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DOP) and new typeenvironmentally-friendly plasticizer acetyl tributyl citrate (ATBC). Gas chromatographcoupled with flame ionization detector (GC-FID) was used for the determination of ethanolextract of these plasticizers from printed paper, milk powder and Tenax (modifiedpolyphenylene oxide, MPPO) as food simulant. A novel method was developed for the studyof migration of plasticizers to milk powder and Tenax from the printed paper at100,70,50and25℃, respectively and for different contact time ranging from5min at100℃and40daysat25℃. The inks were offset printed which simulated the real situation and has never beenused in migration research. The paper weight, ink initial amount, the temperature and theproperties of the compounds are the factors affecting the actual mass transfer process.The results showed that the recovery rate of the sample pretreatment method rangedbetween71.2and113.4%. This method was environmental friendly and low-cost. GC-FIDdetection for each sample cost13minutes with the separation degree of about1minute. Initialconcentrations of the plasticizers in printed paper samples were detected and the relativestandard deviation of plasticizer concentration was±1~3%, indicating that this printingmethod could be well used to prepare the paper samples. The paper did not provide anappropriate barrier against the migration of the plasticizers from printing inks. The maximummigration of DBP and ATBC reached almost67.8%while that of DEHP and DOP was about6.7%. The contact time, the temperature and the properties of the compounds are the factorsaffecting the real mass transfer. Migration of four plasticizers into Tenax and milk powder were tested under microwavepower of100,250,440,600and900W. Discussed the migration factors and compared withthe results under normal conditions. The results showed that the microwave power and themigration time, the closeness of pollutants and paper, food characteristics and other factorsaffect the migration behavior. Pollutants under microwave heating conditions easier migrationoccurs than conventional heating migration occurs more easily in a short time.Applicability of mathematical modelThe applicability of our migration model was validated. The kinetic migration predicted bysingle layer model simplified from the above model was the same as that predicted by theclassic Crank’s diffusion model considering hm. The generality of our model was furtherdiscussed.Using the experimental data of DBP at50℃,70℃and100℃, hmand DPwere fitted by themodel. The relationship between the logarithm of hm/DPand Kelvin temperature are nealylinear. The migration of DBP with different initial concentration was predicted and wascompared with the experimental data. The prediction efficiency was further investigated forpaper with different weight and different initial inks content. The result showed that predicteddata and experimental data matched well.Because DPcalculated from Piringer model could not reflect the influence of moleculepolarity on migration, suitable hmcould be selected to improve the prediction accuracy of themigration of DEHP, DOP and ATBC.更多还原