肉桂醛浓度对浓缩乳清蛋白/壳聚糖复合膜性能的影响

为了研究新型高性能抗菌包装材料,本文将肉桂醛添加到浓缩乳清蛋白/壳聚糖复合膜中制成抗菌复合膜,采用FT-IR对复合膜的微观结构进行表征,研究了肉桂醛浓度对复合膜厚度、透光率、机械性能、水蒸气透过系数、氧气透过率等性质的影响,以及其对复合膜抗菌性能的影响。肉桂醛与浓缩乳清蛋白/壳聚糖复合膜有很好的相容性。结果表明:随着肉桂醛浓度的增加,膜的透光率和抗拉强度减小,当肉桂醛浓度为0.3%时,膜的水蒸气透过系数最小,为1.15×10-13 g/(cm·s·Pa),当肉桂醛浓度为0.4%时,膜的厚度和氧气透过率最小,氧气透过率为1.1×10-5 cm3/(m2·d·Pa),当肉桂醛浓度为0.5%时,膜的断裂伸长率最大,为57.5%,膜的抑菌效力随着肉桂醛浓度的增大而显著增大。该研究可为肉桂醛/浓缩乳清蛋白/壳聚糖复合抗菌膜的生产工艺参数的优化提供新的参考。     

茶多酚-玉米胚芽粕蛋白膜制备及性能研究

以玉米胚芽粕为原料，通过醇法提取玉胚芽粕醇溶蛋白，以丙三醇作为增塑剂，添加壳聚糖提高复合膜液分子间距离，并向其中加入茶多酚，制成复合膜。首先，通过单因素正交试验，研究4个因素对复合膜拉伸强度、水蒸气透过率以及过氧化值指标的影响，以便确定最佳成膜条件，然后，通过测DPPH对其抗氧化性进行分析。试验结果表明：在玉米胚芽粕蛋白浓度为18%、丙三醇添加量为6 g、壳聚糖添加量为0.8 g、茶多酚浓度为2%时，拉伸强度9.24 MPa,水蒸气透过率为2.17 g·mm/(m²·d·kPa),过氧化值为4.23 meq/kg,所测复合膜的各项指标最佳，且成膜效果最好。同时，由于茶多酚的加入，DPPH高达32.57%,抗氧化性明显提高。向复合膜中加入丙三醇、壳聚糖以及茶多酚，使得复合膜各方面性能优化显著，且有效提高了膜的抗氧化性。     

谷朊粉与玉米醇溶蛋白可食性复合膜的研究

研究了谷阮粉和玉米醇溶蛋白可食性复合膜的成膜条件及复合膜的特性。结果表明:复合膜中玉米醇溶蛋白的适宜添加量为25%。在各自最佳成膜条件下,复合膜的水蒸气透过率为5.97g·mm/m2·d·kPa,比对照降低了12.1%;拉伸强度为3.45MPa,比对照提高了22.6%。综合考虑水蒸气透过率与拉伸强度两项指标,确定适宜的成膜条件为:pH12、热处理温度70℃、乙醇浓度55%、甘油浓度10%,此条件下复合膜的水蒸气透过率为6.01g·mm/m2·d·kPa,比对照降低11.5%;拉伸强度为3.39MPa,比对照提高20.7%。该复合膜同时具有良好的热封性。     

静电纺丝法制备玉米醇溶蛋白基纳米纤维抗菌膜

利用静电纺丝技术制备负载百里香酚的玉米醇溶蛋白基纳米纤维抗菌膜,并研究其微观结构、表面接触角、水汽透过率和抗菌物质释放率等性质。实验结果表明,当玉米醇溶蛋白与百里香酚质量比为10∶1时,纳米纤维膜具有一定缓释抗菌物质的能力,其水汽透过率为4. 32 g·mm/(m~2·h·k Pa),表面接触角为104. 36°,表明该膜具有良好的透气性及疏水稳定性,且由于其安全性特别适合医用敷料等方面的应用。当玉米醇溶蛋白与百里香酚质量比为5∶1～1∶1时,纳米纤维抗菌膜对大肠杆菌有一定的抗菌效果,最小抑菌圈直径为8. 68 mm,最大抑菌圈直径为20. 42 mm。     

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。     

玉米醇溶蛋白/纳米二氧化钛复合膜的制备及性质

用溶胶-凝胶法水解四异丙氧基钛(TTIP)制备纳米级二氧化钛(TiO2)粒子,利用该纳米TiO2粒子,用涂膜法制备玉米醇溶蛋白/纳米TiO2复合膜,分析膜中TiO2含量对复合膜性质的影响。复合膜中TiO2含量为14%时,复合膜的拉伸强度最大为35.2MPa,断裂伸长率为3.0%,水蒸气透湿率为169.9g/(m2 ·24h);复合膜的光催化实验表明其具有较强的抗菌作用;扫描电子显微镜和原子间力显微镜观察复合膜结构,可以看出TiO2粒子均匀地分布于复合膜中。     

丁香酚/玉米醇溶蛋白纳米粒子膜的制备及表征

采用反溶剂法构建了丁香酚/玉米醇溶蛋白纳米粒子体系,并将荷载丁香酚的玉米醇溶蛋白纳米粒子制备成纳米粒子膜。以膜的厚度、透光率、机械性能、白度、水蒸气透过系数和透油系数为指标,确定最佳制备工艺条件,并对该条件下制备的产品的抗菌性质进行测定。制得的丁香酚/玉米醇溶蛋白纳米粒子粒径在255~390nm,且具有较好分散度。最佳制膜条件为:玉米醇溶蛋白和80%乙醇固液比为1∶10(g/ml)、甘油质量分数为20%、丁香酚质量浓度为20μg/ml。该条件下制备的产品为淡黄色,较薄,无异味,有较好的机械性能,抗菌性较好。     

海藻酸钠/玉米醇溶蛋白抗菌复合膜的制备及其性能

以海藻酸钠作为基质,加入玉米醇溶蛋白共混制备食品复合包装膜,通过对其物理性能和机械性能的测定分析,从而得到复合膜的最佳海藻酸钠-玉米醇溶蛋白配比,并进一步制作并加入百里香精油抗菌包合物,最终制备具有缓慢释放抗菌物质的活性抗菌复合膜并对其表征和抗菌性能进行分析。结果显示,海藻酸钠与玉米醇溶蛋白成膜液质量比为1∶1时,复合膜具有最佳物理性能和机械性能,此时的复合膜水蒸气阻隔性能和透光率较好,抗拉强度达到最大3.75 MPa,断裂伸长率达到最大42.13%。百里香精油包和物添加量为制膜液总质量的0.2%时,抗菌复合膜的表面平整度和抗菌性有较好的综合效果,并且抗菌效果与百里香精油包合物添加量呈正向关,可以根据此趋势调整添加量,生产所需物化及抗菌性能的抗菌复合膜。     

黑豆皮多酚提取及其对草莓保鲜效果的影响

以乙醇为溶剂提取黑豆皮中的多酚类物质,将其与玉米醇溶蛋白混合制成可食性复合保鲜膜,考察复合膜对草莓的保鲜效果。结果表明:黑豆皮多酚的最佳提取条件为乙醇体积分数85%,提取时间4 h,水浴温度75℃,在该条件下多酚提取量为2.19 mg/g。添加多酚可以增强玉米醇溶蛋白可食性复合膜的保鲜效果,其中添加7%多酚的复合膜对草莓的保鲜效果最优,贮藏6 d时草莓的失重率和腐败率分别为0.43%、49.95%,显著优于对照组。     

抗菌性无定型纳米二氧化钛/聚乳酸膜的制备及表征

溶胶-凝胶法水解异丙醇钛制备纳米二氧化钛（TiO2）溶液,进行粒径优化及表征。紫外光谱、红外光谱、X射线衍射、粒径测试结果表明制备的纳米TiO2为较高可见光利用率的无定型纳米粒子。采用溶液共混法制备聚乳酸/纳米二氧化钛（polylactic acid/nano-TiO2,PLA/nano-TiO2）复合膜,研究不同纳米TiO2质量分数对PLA/nano-TiO2复合膜的性质影响。结果表明,PLA/nano-TiO2复合膜中纳米TiO2质量分数为0.6%时拉伸强度达到最大值,为63.3 MPa,此时断裂伸长率最小,为2.3%。PLA/nano-TiO2复合膜接触角均低于纯PLA膜,从78.40°减小到72.83°;PLA/nano-TiO2复合膜的吸水率显著高于纯PLA膜,从0.56%提高为1.48%;PLA/nano-TiO2复合膜水蒸气透过率比纯PLA膜高,从3.46×10－8（g·m）/（m2·h·Pa）提高到4.66×10－8（g·m）/（m2·h·Pa）。由PLA/nano-TiO2复合膜的抑菌性实验可知,添加纳米TiO2的复合膜在紫外光照下有明显的抑菌效果。     

茶多酚@沸石咪唑酯骨架材料/壳聚糖/海藻酸钠活性包装膜的制备及表征

本实验以海藻酸钠（sodium alginate,SA）和壳聚糖（chitosan,CS）为成膜基材,并以不同添加量（分别为0%（质量分数,后同）、1%、2.5%、5%）茶多酚（tea polyphenols,TP）@沸石咪唑酯骨架材料（zeolitic imidazolate framework-8,ZIF-8）纳米复合材料为功能性成分,通过层层组装的方式制备TP@ZIF-8/CS/SA复合膜。利用场发射扫描电子显微镜、热重分析仪、差示扫描量热仪、傅里叶红外光谱仪、质构仪、色差仪等对复合膜的形貌、组成进行表征。结果表明,TP@ZIF-8纳米复合材料添加量为5%时改变了CS/SA复合膜的颜色,并且影响了复合膜的微观形态,还增强了复合膜的热稳定性、阻隔性能和机械性能。此外,TP@ZIF-8纳米复合材料的加入使该复合膜表现出良好的抗氧化和抑菌效果。综上,本实验制备出一种具有抗菌和抗氧化的生物可降解活性包装膜,该活性包装膜在食品保鲜领域具有良好的应用前景。     

Physicochemical,Microstructural, and Antibacterial Properties of β‐Chitosan and Kudzu Starch Composite Films

Abstract: This study investigated physicochemical, microstructural, and antibacterial properties of β‐chitosan–kudzu starch composite films with addition of 0%, 20%, 60%, or 100% kudzu starch (w starch/w chitosan) in 1% chitosan solution. Molecular interactions between chitosan and kudzu starch and the crystal structure of the films were also determined. Adding 60% kudzu starch reduced water vapor permeability and solubility of pure β‐chitosan film by about 15% and 20%, respectively, whereas mechanical strength and flexibility of the film were increased about 50% and 25%, respectively. Micrograph showed that β‐chitosan film was totally amorphous, and the composite films generally became rougher with more starch added. Fourier transform infrared and X‐ray diffraction spectra showed that the 2 film‐forming components were compatible with each other. Pure β‐chitosan film resulted in 9.5 and 11.5 log CFU/mL reduction in Escherichia coli and Listeria innocua based on plate count method, respectively. Addition of kudzu starch reduced the antibacterial activity of film, but still achieved 8.3 and 10.3 log CFU/mL reduction in E. coli and L. innocua, respectively when kudzu starch to chitosan weight ratio was 1:1. Reduced antibacterial activity might attribute to the interaction of amino groups in β‐chitosan with the hydroxyl groups in kudzu starch. This study demonstrated that kudzu starch effectively improved water barrier of β‐chitosan film, and the composite films retained strong antibacterial ability. Practical Application: One percent of β‐chitosan containing 60% kudzu starch (w/w chitosan) composite films possessed better mechanical and water barrier properties than pure β‐chitosan films, and showed strong antibacterial activity against both Gram‐positive and Gram‐negative bacteria. The films may be used as wraps or coatings to prolong the shelf life of different foods or other similar applications.     

壳聚糖/姜黄素/γ-聚谷氨酸可食性复合膜的制备及对培根和火腿的保鲜效果

以壳聚糖（chitosan,CS）、γ-聚谷氨酸（γ-polyglutamic acid,γ-PGA）为成膜材料,添加姜黄素（curcumin,Cur）制备可食性复合膜,对膜的厚度、水溶性、透明度、表面结构等进行研究,并对其在培根和火腿表面的抗菌保鲜效果进行评价。结果表明：γ-PGA的添加可减小复合膜的厚度,增加膜的水溶性;通过扫描电子显微镜观察到,CS/Cur/γ-PGA复合膜的表面较为紧密;通过分析各单一成分和复合膜的傅里叶变换红外光谱初步推测,复合膜液中CS、Cur、γ-PGA三者之间发生了相互作用。将不同涂膜处理的培根和火腿于28?℃、相对湿度50%条件下贮藏3?d,与市售保鲜膜包装组相比,CS/Cur/γ-PGA复合膜涂膜组肉制品感官品质更优,且菌落总数约低1（lg（CFU/g））。因此,CS/Cur/γ-PGA可食性复合膜的开发有望在食品抑菌保鲜等方面发挥潜在的积极作用。     

添加巴西甜橙油对壳聚糖膜性质的影响

使用浇铸-蒸发-碱浸法制备壳聚糖-巴西甜橙油复合膜,采用红外光谱、X射线衍射对复合膜进行表征,考察巴西甜橙油添加量对膜的厚度、拉伸强度、断裂伸长率、接触角、水蒸气透过系数、总溶解物质量分数、溶胀指数等性质的影响。结果表明：巴西甜橙油占据了壳聚糖骨架中的部分官能团的位置,打乱了壳聚糖骨架的有序性,使膜中壳聚糖乙酸盐的含量增大。巴西甜橙油添加量为2%时,膜的断裂伸长率取得最大值（10.07%）。膜的接触角和总溶解物质量分数随着巴西甜橙油添加量的增加而增大,最大值分别为81.15 °和4.24%。膜的水蒸气透过系数在巴西甜橙油添加量为6%时最小,为313.32 mg•mm/（kPa•h•m2）。壳聚糖-巴西甜橙油（8%）复合膜的溶胀指数最小,为0.49。巴西甜橙油的加入改善了由浇铸-蒸发-碱浸法制备的壳聚糖膜的力学性质和物理性质,研究结果可为壳聚糖-巴西甜橙油复合膜的生产和应用提供技术依据。     

不同聚乳酸膜的抗菌性比较

为了研究添加抗菌剂后,聚乳酸复合膜的抗菌性能,选取了壳聚糖、茶多酚、MgO和银四种抗菌剂,与聚乳酸形成四种复合膜,对比了不同抗菌剂的效果,并利用红外光谱仪对复合膜的结构进行了表征。实验发现,无论哪种抗菌剂,均表现了良好的抗菌效果。当壳聚糖/聚乳酸、茶多酚/聚乳酸均按质量比5:5组成复合膜时,抗菌率分别为68.54%和70.26%,当MgO的添加量为2%时,抗菌率为71.01%,而银表现出了极强的抗菌效果,添加量为1%时,抗菌率达到了98.53%。透光率随着抗菌剂的加入都有不同程度的减小,其中茶多酚的影响最大,从88.67%下降到33.75%。薄膜DSC曲线显示,未添加抗菌剂时,薄膜T_m为80.3℃,添加Ag和MgO后,薄膜T_m分别下降了1.7℃和1.4℃,说明抗菌剂的添加对薄膜T_m几乎无影响。由此可以看出,天然抗菌剂的抗菌效果要略差于无机抗菌剂。     

壳聚糖复合膜在果蔬保鲜中的应用

壳聚糖具有良好的生物相容性、可生物降解性、安全性、成膜性、抗菌性等,常用于果蔬保鲜。但由于机械性能和生物活性不足,为了增强其理化性能和生物活性,常添加生物聚合物、抗菌剂、抗氧化剂等功能成分以提高膜综合性能。综述了壳聚糖膜和壳聚糖/多糖、壳聚糖/蛋白质、壳聚糖/脂质、壳聚糖/抗菌剂、壳聚糖/抗氧化剂等壳聚糖基复合膜在果蔬保鲜中的应用进展,从壳聚糖的诱导活性、成膜特性和抗菌活性三个方面总结了壳聚糖膜的保鲜机理,分析了壳聚糖基复合膜目前在果蔬保鲜实际应用中存在的问题,并对未来发展方向进行了展望,以期为开发安全、高效、绿色、经济的壳聚糖基果蔬保鲜膜提供一定的理论指导。     

EDC和NHS对玉米醇溶蛋白成膜性质的影响

为提高玉米醇溶蛋白膜的抗拉强度和伸长率,降低其水蒸气透过率和吸水率,研究交联剂1-乙基-3-（3-二甲基氨丙基）碳二亚胺盐酸盐（EDC）和N-羟基琥珀酰亚胺（NHS）对成膜性质的影响。结果表明：以90%乙醇为溶剂,EDC和NHS的添加量分别为0.06 g/g时,制得的膜性能最佳,抗拉强度为83 MPa,较未添加交联剂的蛋白膜提高97.6%;伸长率为5.5%,提高57.1%;水蒸气透过率为2.5×10-8（g·m）/（m2·h·Pa）,降低43.2%;吸水率为39.4%,降低24.4%;质量损失率为3.6%,增加20.0%;静态接触角为67.4°,表明膜表面仍为疏水表面。原子力显微镜观测显示,加入交联剂后,蛋白分子聚集体变小,以均一的小球型聚集体形式紧密有序排列。     

Physicochemical,Water Vapor Barrier and Mechanical Properties of Corn Starch and Chitosan Composite Films

Biodegradable flexible films were developed from corn starch (CS) and chitosan (CH); their microstructure, mechanical and barrier properties were evaluated. Chitosan and starch blend filmogenic suspensions showed a pseudoplastic behavior, similar to that of chitosan solutions. Smooth surfaces, homogeneous and compact film structures were observed from microstructure studies using scanning electron microscopy (SEM). The addition of glycerol reduced film opacity and increased film solubility of both CS and composite CS‐CH films. Water vapor permeability values of composite CS‐CH films plasticized with glycerol ranged between 3.76 and 4.54× 10⁻¹¹ g s⁻¹ m⁻¹ Pa⁻¹, lower than those of the single component films. CS‐CH films were resistant and their flexibility increased with glycerol addition. Tensile strength values of CS‐CH films were comparable to those of low‐density and high‐density polyethylenes but lower than that obtained for cellophane, however, composite biodegradable films showed lower elongation at break values than the synthetic commercial ones. In conclusion, CS‐CH films can be described as biofilms with a homogeneous matrix, stable structure and interesting water barrier and mechanical properties, with great possibilities of utilization, and with the advantage of biodegradability.     

Effects of chitosan on the physicochemical and antimicrobial properties of PLA films

Films based on polylactic acid (PLA) and different amounts of chitosan powder (CH), were prepared by extrusion. The effects of CH particle size (715 and 180 μm) and the amount of chitosan incorporated in the PLA matrix (5% or 10% on PLA basis) were investigated in terms of physicochemical characteristics and antimicrobial activity of the films. The incorporation of CH particles led to less rigid and less stretchable films. Thermal properties of PLA were not affected by chitosan addition. Water vapor permeability of the composite films was higher than pure PLA films. PLA:CH composite showed significant antimicrobial activity against total aerobial and coliform microorganisms, especially when the particle size of CH was reduced.     

Fabrication,Gastromucoadhesivity, Swelling,and Degradation of Zein–Chitosan Composite Ultrafine Fibers

Fabrication, via electrospinning, and characterization of an ultrafine structure architected from a blend of hydrophobic zein and hydrophilic chitosan (CS) were conducted. Poly(ethylene oxide) (PEO) and nonionic surfactant, namely, Tween^® 40, were employed to improve the electrospinnability of the blend, while ethanol was used as a solvent for zein. The effects of ethanol (EtOH) concentration (85% and 90%) and ratio of zein/PEO/CS (95/2.5/2.5 and 87.5/10/2.5) on the fiber morphology as well as gastromucoadhesivity against porcine stomach mucosa were then investigated; polymer‐mucosa adhesion was also investigated via Fourier‐transform infrared spectroscopy. Swelling and degradation of the composite ultrafine fibers were investigated under 2 simulated gastric conditions, namely, at pH 2 without pepsin and at pH 1.2 with pepsin. Using 85% EtOH as a solvent for zein resulted in a spider‐web‐like morphology; the maximum detachment force (MDF), which is an indirect indicator of the gastromucoadhesivity was nevertheless higher. Zein‐based ultrafine fibers exhibited higher MDF than the zein‐PEO‐CS composite; however, the cohesiveness of the composite fibers was higher. FTIR spectroscopic results indicated molecular interactions between the composite fibers and mucin functional groups. Swelling of the composite ultrafine fibers in simulated gastric fluid (SGF) at pH 2 without pepsin was not different from that in SGF at pH 1.2 with pepsin. Nevertheless, degradation of the composite fibers in SGF at pH 2 without pepsin was much less than that in SGF at pH 1.2 with pepsin; only 20% degradation was noted in the former case.