纳米氧化锌/低密度聚乙烯膜中锌向食品的迁移研究

目的研究纳米氧化锌/低密度聚乙烯膜(low density polyethylene film,LDPE)中锌(Zn)向食品的迁移行为,探究其迁移规律。方法选取2种食品模拟物(3%乙酸及超纯水)及真实食品(食用白醋及瓶装水),在3种不同实验温度下(70、40及20℃),研究锌向食品模拟物的迁移规律。采用扫描电子显微镜(scanning electron microscope,SEM)和原子力显微镜(atomic force microscope,AFM)表征纳米ZnO/LDPE膜的表面形貌。结果锌向酸性模拟物中的迁移率远远大于水性模拟物中的迁移率,其中锌向酸性模拟物中的最大迁移率分别为22.7%,20.3%及18.6%(ZL-1,ZL-2及ZL-2#),向水性模拟物中的最大迁移率分别为9.9%,5.7%及4.9%(ZL-1,ZL-2及ZL-2#);锌向酸性食品的迁移量(1.59~5.03 mg/g)同样高于向水性食品的迁移量(2.98~24.60μg/g);随着纳米ZnO的初始含量变大迁移率变小;而偶联剂的加入对锌的迁移有一定的抑制作用。随着纳米ZnO浓度的增加,在薄膜中观察到纳米ZnO的不规则形貌。结论纳米ZnO/LDPE膜不适合在高温下包装食物,且其在酸性食品中的安全隐患高于水性食品。     

食品包装材料中双酚A和壬基苯酚迁移量检测方法的研究

采用高效液相色谱-荧光检测法,研究不用食品模拟物(水性、酸性、酒性、脂肪性)中双酚A和壬基苯酚迁移情况。建立了不同食品模拟物中目标物的前处理方法,各类型食品模拟物对应的标准溶液线性良好,相关系数达0.999以上,双酚A和壬基苯酚迁移测定检测的方法检出限分别为0.01 mg/kg、0.01 mg/kg(水性、酸性、脂肪性食品模拟物);0.05 mg/kg、0.05mg/kg(酒性食品模拟物)。采取升温加速试验,对样品中双酚A和壬基苯酚迁移量进行了检测,结果表明,双酚A和壬基苯酚更容易在50%乙醇和异辛烷(油脂替代物)为模拟物的情况下迁出。     

纳米铜/低密度聚乙烯复合膜在乳制品中的铜迁移

采用微波消解-电感耦合等离子体质谱法检测自制纳米铜/低密度聚乙烯(low density polyethylene,LDPE)复合膜中铜在乳制品中的迁移。实验对比复合膜中铜在乳制品及其对应食品模拟物中的迁移,并研究紫外照射处理复合膜后对复合膜中铜在乳制品中的迁移影响,以及蒸煮条件下铜在纯乳中的迁移量。结果表明:用微波消解-电感耦合等离子体质谱法检测纳米铜迁移量的检出限为8.42 mg/kg,定量限为28.06 mg/kg,方法的加标回收率为97.46%～107.30%,精密度为1.98%～6.06%。纳米铜在酸乳中的迁移量比在纯乳中的迁移量高,当纳米铜/LDPE复合膜中铜添加量为1%时,在相同的迁移条件下,纳米铜在酸乳中的迁移量显著高于在纯乳中的迁移量;纳米铜在50%乙醇模拟液中的迁移量显著小于纯乳,差值在39.19～48.94 mg/kg之间,在3%乙酸和4%乙酸模拟液中的迁移量显著高于酸乳,差值分别在1 598.66～1 760.92 mg/kg和1 868.97～2 159.58 mg/kg之间;紫外照射处理复合膜对复合膜中铜在乳制品中的迁移无影响;蒸煮条件下,纳米铜的迁移量也远小于法规中对金属元素迁移量的限定。现行标准中对纯乳和酸乳的食品模拟物的设定不适用于纳米铜。     

高效液相色谱法测定食品模拟物中偏苯三甲酸酐的含量

目的建立高效液相色谱法测定5种食品模拟物中偏苯三甲酸酐迁移量的分析方法。方法以4%(V:V)乙酸溶液、10%(V:V)乙醇溶液、20%(V:V)乙醇溶液、50%(V:V)乙醇溶液、橄榄油分别模拟酸性、水性、酒精类以及油脂类食品,通过高效液相色谱法(high performance liquid chromatography HPLC)测定食品模拟物中的偏苯三甲酸的含量,采用外标法定量,计算出偏苯三甲酸酐的迁移量。结果各模拟物中加标回收率为96.7%~104.0%,相对标准偏差为0.2%~3.7%,水基食品模拟物中该方法的检出限和定量限分别为0.2、0.5 mg/L,橄榄油食品模拟物中该方法的检出限和定量限分别为0.2、0.5 mg/kg。结论该方法具有良好的准确度和精密度,可以准确测定各种食品接触材料中偏苯三甲酸酐的迁移量。     

纳米ZnO/LDPE食品包装膜及食品模拟物中ZnO含量的测定

建立了微波消解/电感耦合等离子体原子发射光谱(inductively coupled plasma atomic emission spectrometer,ICP-AES)及电感耦合等离子质谱仪(inductively coupled plasma mass spectrometer,ICP-MS)对纳米氧化锌/低密度聚乙烯(纳米Zn O/LDPE)薄膜及食品模拟物中Zn O含量的检测方法。根据EU10/2011选择30 g/L乙酸及超纯水为食品模拟物,将纳米Zn O/LDPE薄膜在40℃下浸泡10 d,测定食品模拟物中的Zn O含量。结果表明:Zn在0.03~100μg/L及0.1~5 mg/L的浓度范围内线性关系良好,相关系数不低于0.999 8,在低、中、高3个水平进行加标实验,加标回收率在91.2%~110.2%之间,相对标准偏差(RSD,n=6)为0.3%~6.8%,方法在消解液、30 g/L乙酸及超纯水的检出限(LOD)分别为0.015 mg/L,0.03 mg/L及0.03μg/L,方法的定量限(LOQ)分别为0.05 mg/L,0.1 mg/L及0.1μg/L,方法精密度好,灵敏度高,定性定量准确。采用该方法测得,实验室3种自制纳米复合薄膜中Zn O含量分别为(4.71±0.19),(9.20±0.49)及(12.87±0.33)g/kg,在40℃10 d后,3%乙酸(w/v)食品模拟物中Zn O的含量分别为(2.35±0.02),(3.54±0.01)及(4.12±0.35)mg/kg,在水食品模拟物中Zn O的含量分别为(24.65±0.68),(24.80±1.25)及(45.85±0.32)μg/kg。     

淋膜纸杯中Al、Mg向酸性食品模拟物的迁移及数学模拟

为了研究淋膜纸杯中Al和Mg向酸性食品中的迁移规律以及数学模拟软件模拟迁移的有效性,对8种淋膜纸杯样品采用湿法消解的方法消解,之后利用电感耦合等离子体原子发射光谱(ICP-OES)检测8种淋膜纸杯中Al和Mg的初始含量及其向酸性食品模拟物(3%乙酸溶液)中迁移的量。淋膜纸杯中Al和Mg的初始含量分别为841.6～3 482.0,179.1～19 720.1mg/kg。在迁移条件为40℃/12h,8种样品中Al和Mg向3%乙酸溶液中迁移量分别为0.077～0.212,0.065～0.862mg/kg,而在70℃/8h下8种样品中Al和Mg向3%乙酸溶液中迁移量分别为0.074～0.180,0.064～2.209mg/kg,淋膜层低密度聚乙烯(LDPE)的厚度、迁移温度和时间以及纸的厚度和密度都能影响2种金属元素的迁移。使用迁移模拟软件AKTS-SML对8种淋膜纸杯样品进行迁移模拟,扩散系数采用Piringer模型,纸与LDPE之间的分配系数设置为1 000,LDPE与食品模拟物(3%乙酸)之间的分配系数设置为1,Al和Mg在40℃/12h下迁移模拟结果分别为0.760～3.075,0.162～17.750mg/kg;70℃/8h下迁移模拟结果分别为0.757～3.059,0.161～17.660mg/kg,软件模拟的迁移结果比试验所得到的都要高,迁移模拟结果在一定程度上能取代Al和Mg的迁移试验,确保消费者安全。     

筷子涂层中重金属元素的暴露研究

目的研究筷子涂层中12种重金属元素(锌、铜、镍、镉、铅、汞、铬、钼、硒、砷、钡、锑)在体液模拟物和食品模拟物中的暴露。方法以胃液模拟物、唾液模拟物作为体液模拟物,以4%乙酸(V/V)、水、95%乙醇(V/V)作为食品模拟物,利用电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)法测定筷子涂层中12种重金属元素的溶出量和迁移量。结果对20批次筷子涂层中12种重金属元素的含量进行测试发现10种重金属元素(锌、铜、镍、镉、铅、铬、钼、硒、砷、钡)有检出,其中铅元素含量高达347660.8mg/kg。对检出的重金属元素进一步分析其在体液模拟物中的溶出量和食品模拟物中的迁移量,发现高含量的元素能通过体液模拟物溶出和食品模拟物迁移。结论筷子涂层中重金属元素可能通过3种途径暴露至人体,分别是胃液溶出、唾液溶出、食品中迁移,且涂层涂覆的位置可对重金属元素的暴露途径产生影响;胃液模拟物中溶出量是唾液模拟物中溶出量的10倍以上;4%乙酸(V/V)食品模拟物中的迁移量最多可高于水和95%乙醇(V/V)食品模拟物中的迁移量近1000倍,且随着迁移次数的增加迁移量逐渐降低。     

食品包装材料中双酚A迁移量的测定

建立采用高效液相色谱法对塑料食品包装材料中双酚A向食品模拟物迁移量的检测方法。使用4种食品模拟物：水、质量分数为4%乙酸溶液、体积分数30%的乙醇溶液和脂肪类模拟物(正己烷、异辛烷和橄榄油)。结果表明,双酚A在与食品塑料包装接触过程中,无论在何种情况下都会向食品模拟物中迁移,尤其向醇类模拟物中迁移最严重;在温度超过60℃时,双酚A向食品模拟物中的迁移率骤增;在微波加热条件,高火700W功率时双酚A向食品模拟物中的迁移速率最快。该方法检测限为0.3ng/mL,线性范围为0.5～100ng/mL,线性相关系数为0.9997,回收率在92.0%～102.4%之间,相对标准偏差≤2.84%(n=5)。     

采用ICP-MS研究聚酯类食品包装材料中锑向食品模拟物的迁移规律

目的 建立聚酯(PET)和4种食品模拟物中锑的电感耦合等离子体质谱(ICP-MS)测定方法.用该方法研究PET中的锑向水、10％(V/V)乙醇溶液、3％(W/V)乙酸水溶液和精炼橄榄油4种食品模拟物迁移的行为与浸泡时间、温度、食品模拟物属性、锑初始含量等参数的关系.方法 在不同的温度下,将不同的PET浸泡于食品模拟物中,于一定的时间点吸取少量浸泡液,用ICP-MS测定其含量.结果 ICP-MS方法回收率在94.3％ ～96.1％之间,相对标准偏差在1.38％ ～3.31％之间.结论 锑迁出量随温度升高而增加;随着时间的延长,锑迁出量逐渐增加,一定时间后达到迁移平衡;大部分PET材料本底含量越高迁出量越高;PET中锑易于在酸性食品模拟物中迁出,应少食用PET包装的酸性食品.     

超高效液相色谱法同时测定食品塑料包装材料中紫外吸收剂和抗氧化剂的迁移量

目的建立食品塑料包装材料中限用紫外吸收剂(UV-0、UV-9、UV-71、UV-326、UV-327、UV-234)和抗氧化剂(2246、425、TH-1790、3114和1076)迁移量的超高效液相色谱(ultra performance liquid chromatography,UPLC)测定方法。方法优化仪器条件及模拟液萃取条件,考察超纯水、3%乙酸水(V:V)溶液、10%乙醇水(V:V)溶液及95%乙醇水(V:V)溶液等4种食品模拟物中紫外吸收剂和抗氧化剂的迁移量,并将建立的方法用于市售样品迁移量的检测。结果 11种目标物质在相应的浓度范围内线性关系良好,相关系数r~2大于0.9992,方法检出限为0.5~2.0 mg/L;平均加标回收率为81.2%~113.2%,相对标准偏差(n=6)为2.8%~8.5%。结论该检测方法灵敏、准确,满足欧盟指令(EU)No.10/2011和GB 9685-2008对食品塑料接触材料及制品中紫外吸收剂和抗氧化剂特定迁移量(SML)的限量要求,适用于食品塑料包装材料中紫外吸收剂和抗氧化剂的迁移量的测定。     

Mobility of alpha-tocopherol and BHT in LDPE in contact with fatty food simulants.

The migration/sorption behaviour of butylated hydroxytoluene (BHT) and alpha-tocopherol was studied in packaging material in contact with fatty food simulants. Two low-density polyethylene (LDPE) films, containing either BHT or alpha-tocopherol as antioxidants, were stored in contact with sunflower oil or 95% (v/v) ethanol. The antioxidant content was monitored in the films throughout a period of 7 weeks. The migration of alpha-tocopherol into the food simulants was slower than that of BHT. Since alpha-tocopherol was transferred from the film to the simulant to a lesser extent, it is considered to be a more stable antioxidant than BHT when used in an LDPE film in contact with 95% ethanol or sunflower oil.     

Migration of antimony from PET containers into regulated EU food simulants

Antimony migration from polyethylene terephthalate (PET) containers into aqueous (distilled water, 3% acetic acid, 10% and 20% ethanol) and fatty food simulants (vegetable oil), as well as into vinegar, was studied. Test conditions were according to the recent European Regulation 10/2011 (EU, 2011). Sb migration was assayed by ICP-MS and HG-AFS. The results showed that Sb migration values ranged from 0.5 to 1.2 μg Sb/l, which are far below the maximum permissible migration value for Sb, 40 μg Sb/kg, (EU, Regulation 10/2011). Parameters as temperature and bottle re-use influence were studied. To assess toxicity, antimony speciation was performed by HPLC-ICP-MS and HG-AFS. While Sb(V) was the only species detected in aqueous simulants, an additional species (Sb–acetate complex) was measured in wine vinegar. Unlike most of the studies reported in the literature, migration tests were based on the application of the EU directive, which enables comparison and harmonisation of results.     

Overall migration from commercial coextruded food packaging multilayer films and plastics containers into official EU food simulants

The overall migration from a wide range of commercial five-layer coextruded packaging films into aqueous food simulants (distilled water, 3% aqueous acetic acid) and alternative fatty food simulant (iso-octane) was studied. The overall migration from commercial plastics cups (PS, HIPS, and PP) used for ice-cream or yogurt packaging into distilled water and 3% aqueous acetic acid was also studied. Test conditions for packaging material/food simulant contact and method of overall migration analysis were according to the EU directives and CEN-standards. The results showed that for all tested five-layer films and plastics (PS, HIPS, and PP) cups values of overall migration into aqueous simulants (0.11-0.79 mg/dm², 2.3-15.9 mg/l) and (<0.10-0.41 mg/dm², <0.80-3.1 mg/l) were significantly lower than the upper limit (10 mg/dm²) for overall migration from plastic packaging materials and articles into food and food simulants set by the EU Directive 90/128/EEC and their revisions. The overall migration values from five-layer materials into iso-octane were significantly higher (0.94-8.23 mg/dm², 18.8-164.7 mg/l) than the above values but are still lower than the upper limit for overall migration. Global migration values of five-layer films into aqueous food simulants seems to be independent of material thickness. In contrast, overall migration into iso-octane increases with film thickness.     

食品包装PE材料中荧光增白剂迁移规律的分析

以PE塑料薄膜为研究对象,采用高效液相色谱法研究食品包装塑料材料中荧光增白剂在纯水、乙酸、乙醇、植物油4?种不同模拟物中的迁移规律,研究荧光增白剂溶出量与食品接触介质、乙酸质量浓度、乙醇体积分数、浸泡温度以及处理时间等因素的关系。结果表明：纯水基质食品模拟物对香豆素类荧光增白剂有一定溶解性,酸性食品模拟物相比于水模拟物有更强的溶解性,而含醇类食品模拟物和脂肪类食品模拟物对大部分荧光增白剂都具有较好的溶解效果;荧光增白剂的溶出量随着乙酸和乙醇含量的增加而增加;较高的温度对塑料包装材料中荧光增白剂的迁移溶出具有显著影响,并且随着接触时间的延长,塑料包装材料中的荧光增白剂向食品中迁移的可能性也不断增大。     

Assessment of the migration potential of nanosilver from nanoparticle-coated low-density polyethylene food packaging into food simulants

An experimental nanosilver-coated low-density polyethylene (LDPE) food packaging was incubated with food simulants using a conventional oven and tested for migration according to European Commission Regulation No. 10/2011. The commercial LDPE films were coated using a layer-by-layer (LbL) technique and three levels of silver (Ag) precursor concentration (0.5%, 2% and 5% silver nitrate (AgNO₃), respectively) were used to attach antimicrobial Ag. The experimental migration study conditions (time, temperature and food simulant) under conventional oven heating (10 days at 60°C, 2 h at 70°C, 2 h at 60°C or 10 days at 70°C) were chosen to simulate the worst-case storage period of over 6 months. In addition, migration was quantified under microwave heating. The total Ag migrant levels in the food simulants were quantified by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Mean migration levels obtained by ICP-AES for oven heating were in the range 0.01–1.75 mg l^?1. Migration observed for microwave heating was found to be significantly higher when compared with oven heating for similar temperatures (100°C) and identical exposure times (2 min). In each of the packaging materials and food simulants tested, the presence of nanoparticles (NPs) was confirmed by scanning electron microscopy (SEM). On inspection of the migration observed under conventional oven heating, an important finding was the significant reduction in migration resulting from the increased Ag precursor concentration used to attach Ag on the LDPE LbL-coated films. This observation merits further investigation into the LbL coating process used, as it suggests potential for process modifications to reduce migration. In turn, any reduction in NP migration below regulatory limits could greatly support the antimicrobial silver nanoparticle (AgNP)-LDPE LbL-coated films being used as a food packaging material.     

纳米银-聚乙烯复合包装中银对2 种抗氧化剂向食品模拟物迁移的影响

探究纳米银-聚乙烯复合包装中纳米银成分的存在对2 种抗氧化剂（Irganox1076和Irgafos168）向食品模拟物迁移规律的影响。将含有抗氧化剂的聚乙烯包装膜和同时含有抗氧化剂与纳米银的复合包装膜裁成正方形若干,分别浸泡于正己烷和体积分数95%乙醇溶液2 种食品模拟物中,密封后在20、40 ℃以及70 ℃条件下进行迁移实验。食品模拟物中2 种抗氧化剂的加标回收率在79.3%～108.0%之间,相对标准偏差在0.7%～5.3%之间。2 种抗氧化剂的迁移会随着迁移温度的升高以及迁移时间的延长而增加直至达到迁移平衡,且其在正己烷模拟物中的迁移量大于在体积分数95%乙醇模拟物中的迁移量;含纳米银聚乙烯塑料比不含纳米银聚乙烯塑料中的抗氧化剂向食品模拟物中的迁移量小,表明纳米银成分的存在可以抑制包装中的抗氧化剂向食品模拟物中的迁移。     

聚乳酸抗菌包装中麝香草酚在食品模拟物中迁移规律

研究麝香草酚/聚乳酸包装材料中的抗菌剂麝香草酚在食品模拟物中的迁移行为。在4、10、20、30 ℃条件 下分别将麝香草酚/聚乳酸包装材料浸入蒸馏水溶液、体积分数4%乙酸溶液、正己烷溶液、体积分数10%乙醇溶液 中,通过紫外分光光度法测定食品模拟液中麝香草酚迁移量,分析温度和食品模拟物对麝香草酚迁移量的影响,在 实验数据基础上,采用Piringer方程建立麝香草酚迁移模型,分析验证迁移模型的合理性。结果表明：麝香草酚迁 移量随着迁移温度升高和迁移时间延长而逐渐上升直至平衡,且在4 种食品模拟物中麝香草酚的迁移量大小顺序为： 正己烷＞10%乙醇＞4%乙酸＞蒸馏水;根据幂律方程发现麝香草酚的迁移机制符合Fick扩散定律,且迁移方程扩散系 数随迁移温度升高而增大,分配系数与之相反;Piringer方程能够较好地描述麝香草酚迁移行为。在迁移实验的基础 上构建数学模型,进一步完善基于聚乳酸食品包装材料的迁移理论,以期更好地预测食品包装中麝香草酚的迁移。