聚乙烯醇/壳聚糖/芒果皮提取物复合膜的制备与表征

为了探究芒果皮废弃物的高值化利用,采用微波工艺制备了芒果皮提取物（MPE）。壳聚糖（CS）使用冰醋酸（AAG）或柠檬酸（CA）溶解后,将MPE与聚乙烯醇（PVA）、CS共混,采用溶液浇铸法制备了PVA/CS/MPE复合膜。利用UV、FT-IR、SEM和TG对复合膜的结构、形貌和热性能进行表征分析,对复合膜的力学性能、耐水性、抗菌性、抗氧化性和降解性能进行了测定。实验结果表明:相比于普通搅拌提取（35 °C,500 r/min,4 h,产率13.86%）,微波工艺（35 °C,300 r/min,1 h）下MPE的产率提升至38.26%;复合薄膜各组分之间主要通过氢键作用结合,相容性较好,无明显的相分离;复合膜均表现出良好的抗菌活性和可降解性;CA体系的复合膜拉断伸长率较纯PVA膜提升近一倍,添加MPE后拉断伸长率更高;而MPE能显著改善AAG体系复合膜的耐水性,同时,MPE提高了复合膜的抗紫外、抗氧化能力。因此,所制备的PVA/CS/MPE复合薄膜在医药、食品包装等行业有着广泛的应用前景。     

蛋清蛋白/苹果多酚提高多糖基可食性包装薄膜性能及在腰果贮藏保鲜中的应用

海藻酸钠（sodium alginate,SA）、κ-卡拉胶（κ-carrageenan,κ-C）具有天然无毒、成膜性好的特点,常被用于制备可食用多糖基包装膜。但多糖薄膜具有亲水性强、机械性能差、抗氧化活性低等缺陷。本实验以SA、κ-C为复合多糖成膜基质,以乳酸钙为交联剂,并添加蛋清蛋白粉（egg white powder,EWP）增强多糖薄膜综合包装性能,添加苹果多酚（apple polyphenol,AP）作为抗氧化剂赋予薄膜抗氧化功能。通过傅里叶变换红外光谱、X射线衍射、扫描电子显微镜、紫外吸收光谱等方法分析各组分基团间相互作用,并对腰果仁进行包装贮藏保鲜实验。结果表明：本研究制备的多糖基可食用包装薄膜具有较好的综合包装性能和突出的抗氧化性能。与SA/κ-C薄膜相比,Ca2＋的交联使可食性薄膜的机械性能、阻隔性能显著提升。在最优添加量下,添加EWP使薄膜断裂延伸率由7.99%提高至20.81%,水蒸气渗透率降低了28.84%,氧气渗透率降低了27.07%;加入AP后,可食性薄膜抗张强度由18.58 MPa提升到30.23 MPa,水蒸气渗透率降低了42.35%,氧气渗透率降低了34.13%,同时薄膜阻光性能显著提升。此外,AP/EWP/SA/κ-C可食性薄膜包装降低了腰果仁贮藏期间的水分活度、水分质量分数、过氧化值和酸价,能有效抑制腰果仁的氧化酸败。结论：研究可为多糖/蛋白质基可食性复合包装薄膜的制备及应用提供参考。     

包载山苍子油的醇溶蛋白纳米粒子对明胶膜结构和性能的影响

本文以明胶、玉米醇溶蛋白和山苍子油为基材,通过流延法制备包载山苍子油的醇溶蛋白纳米粒子/明胶复合膜,研究了纳米粒子与明胶的相互作用,以及不同纳米粒子添加量对复合膜的透光性、微观结构、热稳定性、机械性能、疏水性、抑菌和抗氧化性能的影响。结果表明,纳米粒子与明胶之间发生了氢键相互作用,具有良好的相容性。随着纳米粒子添加量的增大,复合膜的透明度显著降低,其疏水性和抗氧化性显著增强（P<0.05）。复合膜对大肠杆菌和金黄色葡萄球菌均具有明显的抑菌活性,其抑菌圈直径分别为（9.17~10.00） mm和（10.02~11.10） mm。当纳米粒子分散液添加量为30%（v/v）时,复合膜的截面最致密,其热稳定性最好,断裂伸长率最大。本研究为开发含有山苍子油的食品活性包装材料提供了一定的参考依据。     

明胶/壳聚糖/迷迭香复合膜的制备与表征

为开发新型具有抗氧化活性的包装材料,以壳聚糖、鱼皮明胶为复合膜基质材料,研究添加迷迭香提取物对复合膜物理性质、微观结构及抗氧化性能的影响。结果表明,添加0.1%迷迭香提取物显著(p<0.05)提高了复合膜的抗氧化性能,将膜的DPPH自由基清除率由15%以下提高到60%以上。迷迭香提取物的添加影响了膜的结构与理化性质。其中,膜的热变性温度由130.97 ℃升至167.52 ℃,同时水溶解性下降了12.62%,但对膜的力学性质没有显著影响。红外光谱显示添加迷迭香提取物影响了O-H键的弯曲和伸缩振动,干扰了复合膜体间的氢键相互作用。研究结果表明,添加0.1%迷迭香提取物既能提高明胶/壳聚糖复合膜的抗氧化能力,又可使复合膜的热稳定性提高,明胶/壳聚糖/迷迭香复合膜活性包装材料具有良好的应用前景。     

纳米TiO2对魔芋葡甘聚糖/玉米醇溶蛋白复合膜结构和性能的影响

本文以魔芋葡甘聚糖、玉米醇溶蛋白为成膜基质,添加不同含量（1%、2%、3%）的纳米TiO₂,以流延方式制备纳米TiO₂/魔芋葡甘聚糖/玉米醇溶蛋白复合膜,并对复合膜的微观结构、热性能、力学性能、疏水性、水蒸气透过率和抑菌性能进行了分析。结果表明,纳米TiO₂与魔芋葡甘聚糖、玉米醇溶蛋白间发生相互作用,有良好的相容性;添加纳米TiO₂使复合膜表面粗糙度增加,复合膜热稳定性和疏水性增强,力学性能降低;纳米TiO₂添加量为1% wt时,复合膜的水蒸气透过率（5.7×10?13 g·cm/（cm2·s·Pa））和溶胀率（16.4%）最小,水接触角值（99.6 °）最大;复合膜对金黄色葡萄球菌和大肠杆菌有明显的抑制作用,对枯草芽孢杆菌的抑制作用不明显。本研究为纳米TiO₂/魔芋葡甘聚糖/玉米醇溶蛋白复合膜作为包装材料的开发与应用提供一定参考依据。     

玉米淀粉/蛋壳粉复合膜的制备及性能分析

以玉米淀粉（corn starch,CS）和蛋壳粉（eggshell powder,ESP）为主要成膜基材制备CS/ESP复合膜。研究CS质量浓度、ESP添加量、丙三醇（glycerol,Gly）添加量3 个因素对CS/ESP膜抗拉强度（tensile strength,TS）、断裂伸长率（elongation at break,EB）、水蒸气透过系数（water vapour permeability,WVP）和氧气透过率（oxygen permeability,OP）的影响。在此基础上采用主成分分析法对膜性能进行综合评价,并通过响应面法优化试验得到CS/ESP膜制备的最佳工艺参数,具体如下：CS质量浓度4.9 g/100 mL、Gly添加量49%（m/m）、ESP添加量1.9%（m/m）,对应CS/ESP膜的TS、EB、WVP和OP分别为4.97 MPa、109.12%、1.31×10－12 g/（cm·s·Pa）和1.19×10－5 cm3/（m2·d·Pa）。傅里叶变换红外光谱分析表明ESP和CS具有较好的相容性。X射线衍射和热重分析结果表明ESP的添加提高了CS/ESP膜的结晶度和热稳定性。扫描电子显微镜分析表明CS/ESP膜具有光滑的表面和断面形貌,没有明显的突起和腔。     

纳米Ag/纳米TiO_2/CS复合膜材料的抗大肠杆菌特性研究

以壳聚糖CS为基质,添加纳米Ag和纳米TiO_2两种抗菌剂所制备的复合膜,针对大肠杆菌的抗菌性研究。实验根据前期单因素实验结果,设计了纳米Ag/纳米TiO_2/CS复合膜材料的三个因素的3个水平的正交实验,制备了不同优化工艺参数下的纳米Ag/纳米TiO_2/CS复合膜材料。同时,对制备的复合膜进行了抗菌性实验。探讨了优化工艺参数下的最优抗菌效果的工艺参数。结果表明:抗菌性最优工艺是:壳聚糖的浓度为4%,硫酸银的浓度为0.05mol/L,二氧化钛为0.007%时,纳米Ag/纳米TiO_2/CS复合膜材料的抑菌效果最好。研究结果为壳聚糖制备成生物质复合抗菌膜提供了理论及实验参考。     

壳聚糖/香兰素/聚乙烯醇共纺纳米纤维膜的性质及其在大菱鲆保鲜中的应用

本研究以壳聚糖（chitosan,CS）、香兰素（vanillin,V）和聚乙烯醇（polyethylene alcohol,PVA）为原料,采用单轴静电纺丝工艺制备CS/V/PVA共纺纳米纤维膜,通过场发射扫描电子显微镜、傅里叶变换红外光谱、X射线衍射、差示扫描量热分析和热重分析对CS/V/PVA共纺纳米纤维膜的形貌和结构进行表征,并以大菱鲆优势腐败菌——腐败希瓦氏菌（Shewanella putrefaciens）为靶标菌,对其抑菌活性进行测定,并考察CS/V/PVA共纺纳米纤维膜应用于大菱鲆的保鲜效果。结果表明：CS/V/PVA共纺纳米纤维膜的微观结构良好,纤维直径均匀分布在200～350 nm之间;纤维膜各组分之间存在相互作用,香兰素分子中的醛基能与CS分子中的氨基反应形成席夫碱键,且CS、香兰素、PVA分子间有氢键形成,降低了膜的初始熔融温度。此外,CS/V/PVA共纺纳米纤维膜对腐败希瓦氏菌具有较强的抑制作用,4 ℃大菱鲆保鲜实验结果表明CS/V/PVA共纺纳米纤维膜能有效延长大菱鲆鱼片的货架期。     

抗氧化型壳聚糖/大豆蛋白复合食用膜的制备与应用

以壳聚糖和大豆分离蛋白为复合膜基材,天然抗氧化剂为活性物质,制备具有抑制脂质氧化且可食用的活性保鲜膜。通过膜的机械性能、微观结构、物理性质与抗氧化性能,优化添加抗氧化剂的种类及浓度,并分析复合膜对核桃油贮藏保质效果。结果表明,8种天然抗氧化剂添加均显著提高了复合膜的阻氧性能（P<0.05）,其中虾青素、葡萄籽提取物、维生素C添加后使得油脂过氧化值减少约80%,且保持良好的机械性能。当虾青素添加浓度为0.3%时,复合膜表现最佳性能,抗拉强度为6.546 MPa,断裂伸长率为69.962%,DPPH自由基清除能力为80.1%,水蒸气渗透率为1.21 g·mm/m2·h·kPa;扫描电子显微镜显示膜表面平整光滑、规则、均匀;红外光谱分析显示成膜材料间均具有良好的相容性;差示扫描热量仪分析表明虾青素复合膜的热焓值最高,达到233.940 J/g,热稳定性最好。将含虾青素的复合膜包裹核桃油后,油脂过氧化值比对照降低81.8%,共轭二烯及共轭三烯值分别下降44.4%和66.4%。添加虾青素的壳聚糖/大豆蛋白复合膜能够显著延缓油脂氧化进程。     

壳聚糖/微晶甾醇可食性复合膜的制备、性能及结构表征

以壳聚糖为成膜基质,添加具有抗氧化和抑菌作用的植物甾醇,采用流延法制备壳聚糖/微晶甾醇可食性复合膜,旨在赋予壳聚糖膜抗氧化活性及提高其抑菌性。当甾醇添加量分别为壳聚糖质量的0%~12%时,随着添加比例的增加,复合膜的拉伸强度和断裂伸长率逐渐下降,溶解度和溶胀度逐渐增加,水蒸气透过系数显著降低,对超氧阴离子自由基(O_2~-·)及羟自由基(·OH)的清除率显著提高,对金黄色葡萄球菌和大肠杆菌的抑菌性能明显增强;采用红外光谱、扫描电子显微镜、X射线衍射和热重分析表征了复合膜的相容性。结果表明:甾醇添加量为9%的壳聚糖/微晶甾醇可食性复合膜各项性能指标良好,且壳聚糖与甾醇分子之间形成了分子间氢键,有较强的相互作用,整个共混体系的相容性良好。     

三赞胶-海藻酸钠可食用复合膜的制备及性能

为探究三赞胶（Sanxan,SAN）与海藻酸钠（Sodium alginate,SA）的协同作用及复合膜的性能,将三赞胶与海藻酸钠以不同质量比复配,以甘油为增塑剂制备复合膜,测定其拉伸强度、断裂伸长率、透光性、溶解性和水蒸气透过率,对复合膜进行差示扫描量热分析,傅里叶红外光谱分析和扫描电子显微镜微观结构表征。结果表明:SAN/SA（5:5）的复合膜拉伸强度最高,与SAN/SA（4:6）的复合膜之间差异不显著（P>0.05）,但显著高于其他比例的复合膜（P<0.05）;当SAN/SA为6:4时,复合膜的柔韧性显著提高（P<0.05）,水蒸气透过率和溶解性最低;差示扫描量热分析表明复合膜的耐热性提高,红外光谱分析表明SAN与SA分子间发生氢键的相互作用,具有较好的相容性和协同作用,微观结构显示复合膜的网络结构排列更规整,膜面的孔隙变小。综上,三赞胶与海藻酸钠具有良好的协同作用,其复配后的SAN/SA复合膜性能显著提高;三赞胶作为新批准应用于食品领域的天然高分子,其应用前景广阔。     

A novel intelligent film with high stability based on chitosan/sodium alginate and coffee peel anthocyanin for monitoring minced beef freshness

This study aimed to develop a novel pH-sensitive intelligent film for monitoring minced beef freshness based on chitosan/sodium alginate (CS–SA) and coffee peel anthocyanin (CPA). The different CPA content effects on the internal structure, physical properties and pH sensitivity of the CS–SA films were investigated. The results showed low contents of CPA (≤2%) could be evenly distributed within the CS–SA matrix with good compatibility. The addition of CPA significantly improved the physical properties and pH sensitivity of the CS–SA films. The CS–SA film containing 2% CPA (CS–SA–CPA2) showed the best tensile strength, water vapour barrier performance and most noticeable colour change. Moreover, this film exhibited good colour stability after 120 days. The CS–SA–CPA2 film changed colour from light yellow to brown to dark brown during minced beef storage, successfully indicating freshness. Therefore, the CS–SA–CPA2 film has the potential to be a pH-sensitive material for monitoring minced beef freshness.     

抗菌性玉米醇溶蛋白/壳聚糖复合膜的制备与性质

采用分步法,先配制壳聚糖/醋酸/乙醇溶液体系,再向其中加入玉米醇溶蛋白,最后利用流延法制成玉米醇溶蛋白/壳聚糖(zein/chitosan,Z/C)复合膜,探讨壳聚糖质量分数对Z/C复合膜理化性质与抗菌特性的影响。结果表明:在壳聚糖质量分数为2%~8%范围内,混合溶液的黏度和电导率随壳聚糖质量分数变化成阶梯状变化,且壳聚糖的添加对复合膜性质有显著影响,Z/C复合膜的断后伸长率从1.00%提高到6.67%,接触角从65.97°减小到53.61°,水蒸气透过率从5.23 g·m/(m2·h·Pa)提高到9.16 g·m/(m2·h·Pa);扫描电子显微镜观察,复合后薄膜保持光滑、均一;大肠杆菌抑菌实验表明添加壳聚糖使复合膜具有较强的抗菌特性。     

复合增塑剂聚乙二醇200与甘油对淀粉/PHA复合膜性能的影响

本文以羟丙基交联木薯淀粉、聚羟基脂肪酸酯(PHA)为成膜基材,甘油(GLY)为主增塑剂,聚乙二醇200(PEG200)为辅增塑剂,有机改性蒙脱土(OMMT)为增强剂,采用挤压吹塑法制备淀粉/PHA复合膜。研究了PEG200与GLY质量比对淀粉/PHA复合膜性能的影响。采用X-射线衍射(XRD)、扫描电镜(SEM)和红外光谱(FT-IR)分别对膜的结构、微观形貌和分子间相互作用进行了表征,并测试了膜的水蒸气阻隔性、机械性能、透光率和色度。结果表明,主增塑剂甘油对淀粉/PHA共混体系具有较好的增塑效果,且随着辅增塑剂PEG200的加入,促进了淀粉、PHA分子与OMMT间纳米插层结构的形成,所成复合膜表面较为平整光滑,且透光率、白度值增加;当PEG200与GLY质量比为8/92时,所成复合膜阻水性较好,具有较高的断裂伸长率;当PEG200与GLY质量比为12/88时,所成复合膜具有较高的抗拉强度和透光率;辅增塑剂PEG200的添加能够增强各分子间的相互作用。在制备淀粉/PHA复合膜中,PEG200是一种较好的增塑剂和增容剂,PEG200与GLY的质量比不宜超过12/88。     

Conductive Polyaniline/Cellulose/Graphite Composite Films with High Thermal Stability and Antibacterial Activity

Functional composite films were successfully prepared from cellulose, graphite (GP), and polyaniline (PANI) using a combination of physical and chemical processes. Cellulose was dissolved in N-methylmorpholine-N-oxide monohydrate (NMMO) and regenerated in water to form the matrix. GP was dispersed in the NMMO solvent prior to the dissolution of the cellulose, and PANI was deposited on the surfaces of the cellulose/GP films by in situ chemical polymerization. The structures of the PANI/cellusose/GP composite films were investigated using X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), and SEM/energy-dispersive X-ray spectroscopy. The mechanical strengths, thermal stabilities, conductivities, and antibacterial activities of the films were studied in detail. The results showed that GP formed a multilayered structure in the cellulose matrix and that the PANI nanoparticles were tightly wrapped on the film surface. The film thickness increased from 40 m to 100 m after the addition of GP and PANI. The tensile strength of the composite films was 80~107 MPa, with the elongation at break being 3%~10%. The final residual weight of the composite films was as high as 65%, and the conductivity of the composite films reached 14.36 S/m. The cellulose matrix ensured that the films were flexible and exhibited desirable mechanical properties, while the GP filler significantly improved the thermal stability of the films. The PANI coating acted as a protective layer during burning and provided good electrical conductivity and antibacterial activity against Escherichia coli; both of these characteristics were slightly enhanced by the incorporation of GP. These PANI/cellulose/GP composite films should be suitable for use in electronics, antistatic packing, and numerous other applications.     

Effect of clay content on the physical and antimicrobial properties of whey protein isolate/organo-clay composite films

Whey protein isolate (WPI)/Cloisite 30B organo-clay composite films with different amounts of the clay (0, 5, 10, and 20 g/100 g WPI) were prepared using a solution casting method and their properties were determined to assess the effects of clay content on film properties. The resulting films had an opaque appearance, which depended on the amount of clay added, and a similar gloss. However, the composite films were slightly less transparent compared to the transparent neat WPI films. Film properties, such as surface color and optical properties, varied depending on clay content. The haze index of the WPI/clay composite films as assessed by surface reflectance decreased indicating that the surface of the films was more smooth and homogeneous. The tensile and water vapor barrier properties of the composite films were also influenced by the amount of incorporated clay. In addition, WPI/Cloisite 30B composite films showed a beneficially bacteriostatic effect against Listeria monocytogenes.     

黑木耳多糖/壳聚糖可食性复合膜的制备及对鲜牛肉的保鲜效果

为了开发具有优良保鲜效果的可食性复合膜,以黑木耳多糖（Auricularia auricular polysaccharide,AAP）和壳聚糖（chitosan,CS）为原料,通过测定复合膜理化指标、结构和抗氧化性,并将不同材料真空包装的冷鲜牛肉于4 ℃条件下贮藏10 d进行保鲜实验,研究不同AAP添加量对AAP/CS可食性复合膜理化性质和冷鲜牛肉保鲜效果的影响。结果表明：AAP的添加可增加AAP/CS复合膜的厚度、密度、溶解度、溶胀度、抗拉强度和1,1-二苯基-2-三硝基苯肼自由基清除率,并降低复合膜的水蒸气透过率和透明度;通过分析复合膜的傅里叶变换红外光谱,初步推测复合膜液中AAP和CS之间发生了相互作用。与市售聚对苯二甲酸乙二酯/聚乙烯复合真空包装组及CS膜包装组相比,AAP/CS复合膜包装组牛肉感官得分和pH值更高,菌落总数和硫代巴比妥酸反应物值更低。因此,AAP/CS可食性复合膜有望在食品抑菌保鲜等方面发挥积极作用。     

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.