纳米羟基磷灰石/玉米醇溶蛋白复合超细纤维的制备与性能

利用静电纺丝制备出纳米羟基磷灰石(nHA)/玉米醇溶蛋白(zein)复合超细纤维。通过场发射扫描电镜、透射电镜观察了纳米羟基磷灰石/玉米醇溶蛋白复合超细纤维的形貌;利用红外光谱仪、X射线衍射仪对纳米羟基磷灰石/玉米醇溶蛋白复合超细纤维结构和性能进行表征,并进行了拉伸测试。结果表明,随着超细纤维中羟基磷灰石含量的增加,纤维的直径先减小后增大,纤维中纳米羟基磷灰石的结晶逐渐变好。相比于玉米醇溶蛋白超细纤维,含有质量分数为25%羟基磷灰石的复合超细纤维仍具有较好的力学性能。     

负载花椒精油的玉米醇溶蛋白-柑橘果胶乳液性能评价

目的 研发出一款新型的花椒精油Pickering乳液,为花椒精油Pickering乳液的制备和花椒精油应用场景的拓宽提供参考。方法 以花椒精油为油相,玉米醇溶蛋白-柑橘果胶复合纳米粒子为固体颗粒,制备花椒精油Pickering乳液。研究复合纳米粒子质量浓度(20、25、30、35、40 g/L)对Pickering乳液粒径、电位、微观结构、稳定性、流变特性等理化性能和抗氧化性能、抑菌性能等功能活性的影响。结果 随着复合纳米粒子浓度的提高,乳液的粒径呈先降后增趋势,ζ-电位绝对值、包埋率则呈先增后降趋势,当质量浓度为35 g/L的时候,乳液粒径最小为1 900.3 nm、ζ-电位和包埋率最大分别为32.7 mV、95%;此浓度下乳液贮藏稳定性最好,且具有优异的温度稳定性,在酸性(pH=2、3、4)和碱性环境(pH=8、9)下稳定性表现良好;所有乳液均显现出明显的剪切变稀行为,属于假塑性流体;在低频下乳液损耗模量大于储能模量,呈流体状态;相较于花椒精油,负载花椒精油的Pickering乳液的抗氧化性能和抑菌性能得到了显著提高。结论 复合纳米粒子质量浓度为35 g/L时制备的负载花椒精油Pickering乳液具有较好的稳定性、抗氧化和抑菌性能。     

松油醇包覆Cu-Ag复合纳米粉的氧化特性

用气-液两相稳定法制备了Cu-Ag复合纳米粉。并用XRD、 HRTEM、 DSC-TG、 红外光谱、 化学分析和氧含量分析等手段研究了粉体的相结构、 表面组成、 形貌、 粒度分布和氧化特性。结果表明, Cu-Ag复合纳米颗粒具有壳核结构, 核为纳米Cu-Ag, 壳为厚度10nm左右的松油醇(C₁₀H₁₈O)分子层和氧化层双层结构, 粉体的粒度分布为20~150nm。在空气中, 220℃包覆在Cu-Ag复合纳米粒子表面的松油醇分子开始氧化, 进而导致Cu-Ag复合纳米粒子在340℃左右迅速氧化, 680℃左右Cu-Ag复合纳米粒子完全氧化。 温度低于220℃时, 气-液两相稳定法制备的Cu-Ag复合纳米粉的抗氧化能力比气相稳定法制备的Cu-Ag复合纳米粉的抗氧化能力好。      

交联β-环糊精聚合物/Fe3O4核壳结构复合纳米颗粒的制备和性能研究

以羧甲基-β-环糊精为表面修饰剂对Fe3O4纳米粒子进行包覆修饰,以环氧氯丙烷为交联剂,在β-环糊精的碱性溶液中通过Fe3O4纳米粒子表面进行的交联反应制备了交联β-环糊精聚合物/Fe3O4复合纳米颗粒.利用FTIR、XRD、TEM和TGA分剐对复合纳米颗粒的结构、形貌和尺寸进行了表征.结果表明,制备的复合纳米颗粒为近球形、核壳结构,粒径约为10～20nm,环糊精聚合物含量为29%,在水中的分散性良好.磁性能测试和包合性能测试表明,复合纳米颗粒为超顺磁性,对特定分子具有一定的包合能力,可用于靶向给药系统和特定物质分离的载体.     

纳米食品保鲜膜研究进展

目的 综述纳米材料及其制备纳米保鲜膜,以及其在食品保鲜中研究和应用现状。方法 介绍常用纳米包装保鲜膜中常用的纳米材料,包括ZnO纳米粒子、TiO₂纳米粒子、SiO₂纳米粒子、介孔SiO₂纳米粒子、Ag纳米粒子,以及纳米保鲜膜制备方法。结果 在传统膜或保鲜膜中添加纳米粒子,可以有效改善膜的力学性能、阻隔性能及抑菌性能,可有效延长食品货架期和贮藏保鲜期。结论 与传统膜相比,纳米膜在食品包装保鲜具有优异特性,具有巨大应用潜力。然而,如何改善光催化等纳米薄膜应用的局限性需要进一步研究。     

改性纳米纤维素/玉米醇溶蛋白可食膜的制备及性能研究

目的 赋予纳米纤维素抗菌性，提高其在食品保鲜中的应用价值。方法 以2,2,6,6-四甲基哌啶-1-氧基(TEMPO)氧化的纤维素纳米纤丝(TOCNF)为原料，利用没食子酸(GA)对TOCNF进行改性，获得改性后的纤维素纳米纤丝(GA-TOCNF)，并将其与玉米醇溶蛋白(Zein)共混制备可食性薄膜，探究GA-TOCNF和Zein不同比例对所制薄膜性能的影响。结果 当GA-TOCNF与Zein溶液的体积比为1∶2时，制备的没食子酸改性纳米纤维素/玉米醇溶蛋白复合膜(GA-TOCNF/Zein)的拉伸强度为9.04 MPa，对大肠杆菌和金黄色葡萄球菌的抑菌圈直径分别为11.95 mm和13.1 mm。与不添加GA-TOCNF的薄膜相比，GA-TOCNF/Zein的拉伸强度提高了1.89倍。结论 综合评价圣女果质量损失率、可溶性固形物和感官评价等指标可得，玉米醇溶蛋白基复合膜对圣女果的涂膜保藏效果优于不涂膜对照组的保藏效果。     

磁性/荧光双功能纳米颗粒的制备及性能研究

通过对Fe3O4纳米颗粒的SiO2包覆和表面胺基化修饰,成功地将CdSe量子点（QDs）均匀地包覆在Fe3O4纳米粒子表面,制备了稳定的、具有磁性/荧光双功能的纳米颗粒,结果表明,所制备的纳米颗粒具有良好的分散性、优异的磁响应特性和荧光发射性能,为制备该类双功能纳米材料,拓宽其应用领域提供了新的途径。     

氧化物包覆金属复合纳米粒子的形成机制及稳定性研究

在传统的“汽-液-固（VLS）”生长机制的基础上，提出了“定量氧辅助汽-液-固（SOA—VLS）”生长机制，解释了氧化物包覆金属复合纳米柱子的形成机制和过程，并利用直流电弧等离子体法制备出多种氧化物包覆金属复合纳米粒子，如氧化硅包覆、氧化硼包覆、氧化钛包虔和多种稀土氧化物包覆的金属纳米壳／核结构复合粒子。本文着重介绍了氧化硼包覆金属复合纳米粒子的结构特征，以及温度敏感特性和酸碱腐蚀性。     

原位包覆金属纳米粒子的规模化制备及应用

介绍激光感应复合加热制备金属纳米粒子的方法,以及基于该技术原位制备碳包覆金属纳米粒子和有机物包覆金属纳米粒子,概括了原位包覆金属纳米粒子的应用。根据实际应用条件选择合适的包覆方法和包覆材料,可以极大地提高金属纳米粒子的产品性能和适用性,获得更高的应用价值。     

化学镀法制备纳米Cu/Al复合粉末

为了改善超细铝粉的表面易氧化问题和微米级铝粉对推进剂的热分解催化作用不明显现象,以对推进剂具有良好催化作用的纳米Cu包覆金属Al表面.采用化学镀铜法对微米级铝粉表面进行镀覆,制备出纳米Cu粒子在超细Al颗粒表面包覆完整的Al-Cu核壳式复合粉末,并利用正交实验优化镀液组分及镀覆工艺条件.利用XRD、SEM、EDX等仪器,对复合粉末的形貌、物相结构及表面成分进行分析,结果表明铝粉表面包覆一层致密的纳米铜层,这种纳米层是由粒度约为18.83nm的晶态析出的纳米铜组成.     

生物基抗菌剂的制备及其改性PVA薄膜保鲜研究

目的 为了增加聚乙烯醇(Polyvinyl Alcohol,PVA)薄膜作为食品包装材料的抗菌性能,促进生物基绿色环保助剂发展和应用,推动绿色包装理念。方法 以香草醛、色氨酸、半胱氨酸、酪氨酸、苏氨酸、苯丙氨酸等为原料设计合成系列生物基多官能席夫碱型抗菌剂,制备相应的席夫碱抗菌剂薄膜,并对抗菌剂进行结构表征、热学性能测试,对抗菌复合薄膜进行力学性能、透湿性能、抗菌性能、保鲜性能的测试和表征。结果 5种新型氨基酸席夫碱抗菌剂均具有较好的抗菌性能,制备的薄膜延长了圣女果的货架期2~4 d。结论 新型绿色环保生物基席夫碱抗菌剂具有十分优异的抗菌性能,改善了PVA的抗菌性能,延长了圣女果的货架期,推动了绿色包装的发展。     

Novel pineapple leaf fibre composites coating with antimicrobial compound as a potential food packaging

Biodegradable packaging coated with antimicrobial compounds has emerged as a new type of food packaging with potential to enhance food safety, extend shelf life and minimize plastic pollution. We have developed a polylactic acid (PLA) composite pineapple leaf fibre (PALF) biopolymer to fulfil the high demand of biodegradable materials for a potential use in food packaging. Our formulation with 10% pineapple fibre PLA/PALF composites exhibited enhanced melting temperatures and heat resistance, with a 44% reduction in the tensile strength and 2.7-fold reduction on the strain at the break when compared with neat PLA. To impart antimicrobial activity, the PLA/PALF was coated with crude supernatants isolated from Pediococcus pentosaceus PP04 containing 1.3% w/v of nisin. This material coated with the crude extract was shown to inhibit the growth of Bacillus cereus ATCC 11778, Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311, and Escherichia coli ATCC 8739 in culture conditions, as well as minimizing the number of the tested pathogens on coated material surfaces.     

Low‐density Polyethylene Films Loaded by Titanium Dioxide and Zinc Oxide Nanoparticles as a New Active Packaging System against Escherichia coli O157:H7 in Fresh Calf Minced Meat

Antibacterial packaging is introduced as a new method to prevent microbial food spoilage. Antibacterial effects of TiO₂, ZnO and mixed TiO₂–ZnO nanoparticle‐coated low‐density polyethylene (LDPE) films on Escherichia coli PTCC1330 were investigated. Bactericidal efficiency of 0.5%, 1% and 2% TiO₂ and ZnO nanoparticles and also 1% mixed TiO₂–ZnO nanoparticles with ratios of 25/75, 50/50 and 75/25 were tested under ultraviolet (UV) and fluorescent lights at two states: films alone and fresh calf minced meat packed. Maximum colony‐forming unit (CFU) reduction of 99.8% and 99.7% were obtained using 1% and 2% ZnO nanoparticle‐coated LDPE film under fluorescent light for films alone as well as 99.8% and 99.6% for fresh calf minced meat packed. 90.3% and 51.8% CFU reduction were recorded for 1% TiO₂ nanoparticle‐coated LDPE films in the presence of UV light at direct contact with bacteria and fresh calf minced meat packed, respectively. Maximum CFU reductions of 96% and 64.1% were obtained using 50/50 ratio of TiO₂/ZnO nanoparticles at the presence of UV light for film alone and fresh calf minced meat packed, respectively. ZnO nanoparticle‐coated LDPE films were identified as the best case to improve shelf life and prevent E. coli growth in fresh calf minced meat.     

明胶-壳聚糖-迷迭香提取物复合膜对冷藏鲟鱼品质的影响

目的 制备明胶-壳聚糖-迷迭香提取物复合膜（G-C-RE）,并研究其对冷藏鲟鱼的保鲜效果。方法 通过测定菌落总数、pH值、挥发性盐基氮（TVB-N）含量、硫代巴比妥酸（TBARS）含量、感官评价等指标来探究复合膜对鲟鱼贮藏品质的影响。结果 鲟鱼经复合膜处理后感官评分得到提高,特别是在维持鲟鱼气味上表现出显著的效果。在贮藏第6 d时,复合膜处理后鲟鱼的TVB-N值和TBARS值分别比对照组低27.7%和62.5%（P<0.05）,使冷藏鲟鱼的货架期从6 d延长至8 d,并使鲟鱼的菌落总数在第10天时才达到国标限值。结论 明胶-壳聚糖-迷迭香提取物复合膜具有抑菌和抗氧化作用,可保持鲟鱼的良好品质,有望成为一种新型的食品活性包装材料。     

Development of novel chitin/nanosilver composite scaffolds for wound dressing applications

Antibiotic resistance of microorganisms is one of the major problems faced in the field of wound care and management resulting in complications like infection and delayed wound healing. Currently a lot of research is focused on developing newer antimicrobials to treat wounds infected with antibiotic resistant microorganisms. Silver has been used as an antimicrobial agent for a long time in the form of metallic silver and silver sulfadiazine ointments. Recently silver nanoparticles have come up as a potent antimicrobial agent and are finding diverse medical applications ranging from silver based dressings to silver coated medical devices. Chitin is a natural biopolymer with properties like biocompatibility and biodegradability. It is widely used as a scaffold for tissue engineering applications. In this work, we developed and characterized novel chitin/nanosilver composite scaffolds for wound healing applications. The antibacterial, blood clotting and cytotoxicity of the prepared composite scaffolds were also studied. These chitin/nanosilver composite scaffolds were found to be bactericidal against S. aureus and E. coli and good blood clotting ability. These results suggested that these chitin/nanosilver composite scaffolds could be used for wound healing applications.     

茯苓–聚乙烯醇抑菌膜的制备及生物可降解动力学评价

目的 以可降解材料聚乙烯醇为基材,通过添加茯苓溶液,制备出复合抑菌薄膜,研究不同浓度茯苓对共混膜理化性能和功能性能的影响。方法 采用溶剂浇铸法制备茯苓/PVA共混膜。对共混膜的物理力学性能,以及溶解度、透光率、抑菌性、可降解性进行检测。利用红外光谱、扫描电镜对其结构进行分析表征。结果 茯苓的添加削弱了PVA分子间作用力,显著提高了断裂伸长率,由202.77%增加到398.82%,降低了拉伸强度,并且茯苓与PVA之间形成氢键,减少了水分对薄膜的溶解,薄膜溶解度由100%降到38.21%。随着茯苓质量分数的增加,薄膜的透光率下降,抑菌性得到增强。土壤降解实验表明茯苓/PVA共混膜具有良好的生物降解性。结论 制备的茯苓/PVA共混膜的力学性能和耐水性均得到提高,并且复合膜具有一定的抑菌性和可降解性。文中制备的复合膜为食品包装提供了理想选择。     

Evaluation of alginate and zein films as a carrier of natamycin to increase the shelf life of kashar cheese

The aim of this study was to develop alginate and zein films containing natamycin, a natural antifungal agent, in order to limit/prevent the mould growth on the surface of kashar cheeses. The films were prepared by casting, and characterized in terms of antimicrobial and mechanical properties (tensile strength, elongation-at-break, and elastic modulus), and their morphology was examined by scanning electron microscopy (SEM). Mechanical properties of the zein films were found to be weaker than the alginate films. SEM analysis indicated that alginate films have a more regular structure than zein films, and a more homogenous distribution was observed at lower concentrations of natamycin. The antifungal activities of both films increased as the natamycin concentration (100, 200, 500, 1000, 2000, and 4000 ppm) increased; however, alginate films exhibited relatively high antifungal activity. The effects of films on the shelf life of kashar cheeses inoculated with Aspergillus niger and Penicillium camemberti were investigated during their storage under refrigerator conditions for 45 days. At high-natamycin concentrations, zein films showed higher antifungal activity against both fungi at the end of the storage period.     

抗菌涂层和抗菌塑料在食品包装中的研究发展

目的从可食用抗菌涂层和食品抗菌塑料包装的角度出发提升食品的品质安全,满足消费者对安全优质食品的追求。方法根据食物的腐烂周期和保质方式的特点,系统性地总结目前可食用抗菌涂层的几种主要覆盖技术,以及非食用性抗菌塑料的载体和制备方法,并将其运用到食品的包装设计中。结论针对保鲜周期短的易腐食品和保质期较长的常规食品提出了可行的包装方案,对可食用抗菌涂层和非可食用性抗菌塑料在未来食品包装领域的发展和研究做了指向性分析。     

Chitosan‐based nanofibers as bioactive meat packaging materials

Shelf life and safety of minimally processed food are crucial for both consumers and the food industry. This study investigates the in vitro and in situ efficiency of electrospun chitosan‐based nanofibers (CNFs) as inner part of a multilayer packaging in maintaining the quality of unprocessed red meat. Activated CNF‐based packaging (CNFP) were obtained by direct electrospinning of chitosan/poly(ethylene oxide) solutions on top of a conventional multilayer food packaging. The electrospinning solutions were firstly characterized at the molecular level, mainly in terms of zeta potential and viscoelastic properties, and the evolution of the conformational structure was correlated to the nanofiber formation process. The oxygen and water vapor barrier properties of CNF‐based (CNFP) meat packaging were also investigated. The in vitro antibacterial activity of CNFs was determined against Escherichia coli, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Listeria innocua, bacteria commonly incriminated in the alteration of food products. The efficiency of the CNFP materials against meat spoilage by E. coli was also assessed. Our results indicate that the electrospinning of CS is a multifactorial process and fiber formation requires the choice of a good solvent, high electrical conductivity, moderate surface tension, optimum viscoelastic properties, and sufficient chain flexibility and entanglement. The results also indicate that all the tested bacterial strains were significantly sensitive to the action of CNFs. The in situ bioactivity against E. coli showed the potential of CNFP as bioactive nanomaterial barriers to meat contamination by extending the shelf life of fresh meat up to 1 week.