Release properties of cinnamaldehyde loaded by montmorillonite in chitosan-based antibacterial food packaging

This work aimed to prepare a controlled-release antibacterial food packaging film by solvent volatilisation using chitosan (CS) and acidified modified montmorillonite (MMt) loaded with CIN (acid-MMt-CIN). MMt was successfully acidified and CIN was successfully loaded into acid-MMt, which had been confirmed by X-ray diffraction. The coordination of acid-MMt-CIN significantly increased the barrier properties of CS film to water vapour, as well as the rigidity and ductility of the film. Furthermore, the CS/acid-MMt-CIN film could significantly improve their UV resistance. It was found that the CIN release time of CS/acid-MMt-CIN film in isooctane (simulated fatty food) could reach 168 h, which was 72 h longer than that of CS/CIN film. The addition of acid-MMt-CIN had a significant inhibitory effect on Staphylococcus aureus and Escherichia coli. In short, CS/acid-MMt-CIN film could potentially be used as an antibacterial active food packaging film.     

Preparation and characterization of chitosan/halloysite nanotubes composite film with ethylene scavenging and gas resistance for active food packaging

In this study, the halloysite nanotubes (HNT) were incorporated into chitosan (CS) to prepare CS/HNT composite film by solution-casting method. Different HNT contents were studied in relation to the morphological, optical, mechanical, barrier and thermal properties of CS/HNT composite films. After incorporation of HNT, the CS/HNT composite films showed improvement in UV light shielding, barrier against water vapor and oxygen, mechanical strength and thermal stability as well as achievement of ethylene scavenging property. Especially, when 5 wt% HNT were added, more homogenous distribution of HNT in CS matrix was observed by SEM, resulting in 169.9% increase in tensile strength, 52.94% decline in oxygen permeability and 4.07 times enhancement in the ethylene scavenging capacity at 100 kPa pressure compared with pure CS film. Moreover, the obtained film with 5 wt% HNT effectively maintained the freshness of bananas and cherry tomatoes under ambient conditions. This study demonstrated that the CS/HNT composite films could be used as active food packaging material to extend the shelf-life of fresh fruits and vegetables.     

纳米银/低密度聚乙烯复合食品包装薄膜的表征及性能

将纳米银(Ag)或助剂(光稳定剂783、抗氧剂B900)通过熔融共混的方法添加到低密度聚乙烯(low density polyethylene,LDPE)基材中,再通过挤出机造粒,吹膜机吹塑成薄膜,即制得纳米Ag/LDPE复合食品包装薄膜。借助扫描电子显微镜(Scanning Electron Microscope,SEM)分析了薄膜中纳米银的粒径分布情况;借助原子力显微镜(Atomic Force Microscope,AFM)分析了薄膜的表面微观形貌;对薄膜的力学拉伸性能、透湿性能、透光性、颜色做了相关的测试分析。结果表明,添加纳米银或光稳定剂783、抗氧剂B900会增加LDPE膜的粗糙度,降低LDPE膜的透光性;添加纳米银降低薄膜的断裂伸长率,增加LDPE膜的粗糙度,且使材料颜色偏暗偏黄;所添加的助剂对材料的颜色无影响,但会增加膜的粗糙度。      

纳米二氧化钛抗菌食品包装复合膜的研究进展

纳米二氧化钛具有较好的抗菌作用,且在传统包装材料中有较好的分散性,添加了纳米二氧化钛的食品包装薄膜具有较好的抗菌效果,能在一定程度上延长食品的保质期。目前,有较多关于纳米二氧化钛食品包装复合膜的研究,主要是围绕抗菌性,机械性能和安全性等方面展开,研究表明：纳米二氧化钛复合膜的抗菌性受光照影响;复合膜的机械性能、热力学性能和阻隔性等随纳米二氧化钛的加入有所改变;复合膜中的纳米二氧化钛可能会迁移到包装的食品中,造成食品安全隐患;制备复合膜时需综合考虑以上因素。本文主要对纳米二氧化钛的抗菌机理、纳米二氧化钛抗菌食品包装薄膜的制备和应用、纳米二氧化钛的迁移研究进展进行概述,旨在扩展纳米二氧化钛复合膜更好更安全地应用于食品包装。     

PVA/starch/propolis/anthocyanins rosemary extract composite films as active and intelligent food packaging materials

Active and intelligent food packaging films has taken more importance over conventional packaging. The aim of this study was to develop active and intelligent food packaging films based on bio-degradable polymers like polyvinyl alcohol and starch, incorporated with natural additives, that is, propolis extract (PE) and Anthocyanin. Boric acid was used as a cross-linker. The results proved the compatibility of films mixture. The mechanical strength was also measured and highest value was achieved 6.1 MPa for films containing 20% PE. Moreover, the maximum zone of inhabitation, that is, 21 and 15 mm, was also achieved at same composition against Escherichia coli and methicillin-resistant Staphylococcus aureus, respectively. Furthermore, all films had shown great color response against different pH ranging from 2 to 14. Finally, food spoilage test was performed using pasteurized milk. Films responded visibly by changing color and protected milk from spoilage. Hence, formulated bio-degradable active and intelligent films can be used as food packaging material.     

探讨新鲜食品薄膜的包装功能

<正> 在现今社会追求方便的前提下,超级市场内出售的新鲜蔬菜和肉类越来越普及,并深受消费者的欢迎。对于这些新鲜食品来说,产品本身的质量固然重要,其使用的包装物料及容器,在保持食品新鲜上也起着重要的作用。因此,透明且具优质保鲜性能的薄膜包装便成为新鲜食品的理想包装材料。随着消费者对使用薄膜包装的新鲜     

Improvement of active chitosan film properties with rosemary essential oil for food packaging

Rosemary essential oil (REO) was used to develop an active film from chitosan. The effects of REO concentration (0.5, 1.0 and 1.5% v/v) on film properties were studied by measuring the physical, mechanical and optical properties of the REO‐loaded films. Scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy were used to study microstructure and the interaction of the chitosan‐based films. The solubility and water gain of the chitosan film decreased about 25% and 85%, respectively, by REO incorporation, up to 1.5% v/v, because of the interaction between hydrophilic groups of chitosan and REO as confirmed by FTIR. It was determined that REO improved the transparency of the films from 4.97 in neat chitosan up to 7.61; moreover, it reduced the films’ light transmission in UV light more than 25%. Films containing REO showed more antibacterial activity and total phenol content. The films containing REO showed potential to be used as active film in food preservation.     

介孔分子筛搭载槲皮素食品抗氧化活性包装膜制备及其性能研究

以十六烷基三甲基溴化铵(CTAB)和聚(乙二醇)-block-聚(丙二醇)-block-聚(乙二醇)Mn~2900(P131345)作为双模板剂制备出纳米二氧化硅介孔分子筛MCM-41(Mobil Composition of Matter No.41),并进一步以此为载体搭载天然抗氧化剂槲皮素,以低密度聚乙烯(LDPE)为基材制备了一种食品抗氧化活性包装膜。结果表明,所制备纳米二氧化硅介孔分子筛MCM-41比表面积为439.173 m²/g,孔体积为0.665 cm³ g^-1,孔径分布为2.4、4.0 nm。吸附槲皮素后,其1,1-二苯基-2-三硝基苯肼(DPPH)自由基在经过24 h和1200 h后平均清除率分别为56.75%和66.01%。同时,槲皮素在食品模拟物中的扩散速率D(cm²/s)由2.127×10^-13下降到3.089×10^-14。表明以介孔分子筛为载体制备的食品抗氧化活性包装膜具备抗氧化的作用并具备缓释性。     

生物基活性食品包装材料的研究进展

传统的塑料食品包装材料大多来自于不可再生的石化资源,难以降解,不仅造成白色污染,且包装中的某些成分迁移至食品中也给食品安全带来负面影响。随着对“双碳目标”的认知和食品安全关注度的提升,绿色、安全、可降解同时可延长食品的保质期的生物基活性包装材料成为研究热点。本文从活性剂的类型和活性包装的功能角度介绍了生物基活性基材的类型和特点,综述了基于淀粉、纤维素、壳聚糖、蛋白质、聚乳酸等生物基材的活性食品包装材料的研究现状,对比分析不同类型生物基活性包装的优势和弊端,探讨各生物基食品活性包装材料存在的问题及解决的对策,最后对未来生物基活性包装的应用和研究趋势进行展望,以期为开发和选用绿色环保、性能优良、使用安全的生物基活性食品包装提供参考。     

Individual wrapping of radishes with food packaging film

When ‘Taibai’ radishes were individually wrapped with food packaging film, they had a reduced weight and firmness loss and a decreased formation of internal sponginess. When stored at 1 °C, wrapped radishes lost 0.01% of their fresh weight per day when compared with the 0.28% weight loss per day for unwrapped radishes. When stored at 5 °C, wrapped radishes lost 0.02–0.03% of their fresh weight per day when compared with the 0.78% weight loss per day of unwrapped radishes. Wrapped radishes stored for 88 days at 5 °C or 165 days at 1 °C maintained their firmness better than unwrapped radishes. Wrapped radishes had significantly less internal sponginess than unwrapped radishes.     

Development of an antimicrobial material based on a nanocomposite cellulose acetate film for active food packaging

Nanocomposites based on biopolymers have been recognised as potential materials for the development of new ecofriendly food packaging. In addition, if these materials incorporate active substances in their structure, the potential applications are much higher. Therefore, this work was oriented to develop nanocomposites with antimicrobial activity based on cellulose acetate (CA), a commercial organoclay Cloisite30B (C30B), thymol (T) as natural antimicrobial component and tri-ethyl citrate (TEC) as plasticiser. Nanocomposites were prepared by a solvent casting method and consisted of 5% (w/w) of C30B, 5% (w/w) of TEC and variable content of T (0%, 0.5% and 2% w/w). To evaluate the effect of C30B into the CA matrix, CA films without this organoclay but with T were also prepared. All nanocomposites showed the intercalation of CA into the organoclay structure; furthermore this intercalation was favoured when 2% (w/w) of T was added to the nanocomposite. In spite of the observed intercalation, the presence of C30B inside the CA matrices increased the opacity of the films significantly. On the other hand, T showed a plasticiser effect on the thermal properties of CA nanocomposites decreasing glass transition, melting temperature and melting enthalpy. The presence of T in CA nanocomposites also allowed the control de Listeria innocua growth when these materials were placed in contact with this Gram-positive bacterium. Interestingly, antimicrobial activity was increased with the presence of C30B. Finally, studies on T release showed that the clay structure inside the CA matrix did not affect its release rate; however, this nanofiller affected the partition coefficient K_P/FS which was higher to CA nanocomposites films than in CA films without organoclay. The results obtained in the present study are really promising to be applied in the manufacture of food packaging materials.     

快速分析食品包装复合膜材质结构的方法研究

目的 研究快速分析食品包装复合膜材质结构的方法.方法 将样品用夹具固定,切片机切片处理后获得材料横截面,并标记样品内外层,利用扫描电子显微镜仪(scanning electron microscope,SEM)对样品层数和由外到内厚度进行表征和测量.利用衰减全反射(attenuated total reflection...     

聚乳酸/曲酸抗氧化活性包装膜的制备及性能研究

以聚乳酸(polylactic acid, PLA)为基材,曲酸为抗氧化剂制备活性包装膜,研究了不同浓度曲酸对复合膜物理性能、力学性能及抗氧化活性等的影响,为开发新型食品活性包装材料提供依据。结果表明,加入曲酸后,薄膜的抗氧化性能显著提高。曲酸的加入也提高了复合膜的厚度,增加了膜的颜色,但不透明度降低。薄膜的断裂伸长率随曲酸浓度的增加而增加,红外光谱显示4%曲酸导致聚乳酸膜出现了新的■双键特征峰,显著加强聚乳酸膜分子链的相互作用,能够观察到苯环骨架的伸缩振动,新形成的■等化学键也导致薄膜有着较高的抗拉强度,表面产生了明显的波纹。综合来看,添加4%的曲酸能提高膜的抗氧化性能和力学性能,能获得理想的复合膜。     

明胶—壳聚糖可食性复合包装膜性能影响因素

主要研究明胶含量、明胶浓度,甘油含量对明胶―壳聚糖可食性复合膜性能影响。通过对复合膜厚度、抗拉强度、断裂伸长率及透光率检测表明,明胶在成膜液中含量、浓度及甘油含量均对复合膜性能具有显著影响。     

聚乙烯醇/二氧化硅/肉桂醛复合膜的制备及应用

为开发新型食品包装材料,以聚乙烯醇(polyvinyl alcohol,PVA)为基质,添加肉桂醛(cinamaldehyde,CIN)和纳米二氧化硅(n-SiO2)制备复合包装膜(PVA-CIN-Si),研究了该复合膜对樱桃番茄的保鲜效果.采用扫描电镜(scanning electron microscope,SEM...     

水产品活性包装和智能包装技术的研究进展

水产品贮藏品质对加工保藏技术的要求以及国内消费者对水产品加工食品质量安全的存疑促进了水产品活性包装和智能包装技术的发展。活性包装技术通过包装材料吸收不利保藏的成分,或释放有利保藏的成分,或发挥涂膜抗菌、抗氧化作用,对水产品起到防腐保鲜的作用。智能包装技术通过标签指示剂、信息溯源提高产业链管理效率以及减少消费者对水产品品质和安全的担心。虽然国内外在水果、蔬菜、奶制品等食品上已有新包装技术的应用,但是我国水产品活性包装和智能包装的工业化尚在起步阶段。本文总结了主要的活性包装和智能包装技术,并总结了新包装技术在国外水产品上的应用,以期为我国未来水产品新包装的发展提供借鉴参考。     

氧化石墨烯对壳聚糖/氧化石墨烯复合膜性能的影响研究

采用改性Hummer’s方法制备了氧化石墨烯,将氧化石墨烯（GO）以不同的掺杂比与壳聚糖（CS）醋酸溶液进行混合后,用溶液共混法制备出壳聚糖/氧化石墨烯（CS/GO）复合膜,通过FT-IR、XRD技术对复合膜结构进行了初始表征,并测试了其力学性能、水蒸气透过率、阻氧性、水溶性及透明度。实验结果表明:氧化石墨烯的含氧基团与壳聚糖分子之间有较强的氢键作用;氧化石墨烯的加入,能够提高膜的拉伸强度和水溶性,降低其水蒸气透过率、透明度及阻氧性,但对其断裂延伸率影响不大;与壳聚糖膜相比,CS膜液与GO溶液体积比为4∶6的复合膜综合性能最好,其拉伸强度和水溶性分别提高了38.8%、17.9%,水蒸气透过率、阻氧性及透明度分别降低了16.9%、42.5%、14.8%。