产单宁酶海洋短梗霉的分离筛选及酶学性质的研究

单宁酶能水解单宁物质中的酯键,在食品和饲料工业中有重要应用价值。 该研究从海洋微生物中获得了几株高产单宁酶 菌株,其中菌株95水解圈与菌落（直径）大小的比值最大,对其进行生理生化鉴定,并扩增内转录间隔区（ITS）序列作进化树分析, 鉴定菌株95号为Aureobasidium subglaciale,其在发酵培养基中发酵72 h达到最大酶活力323.2 U/mL。 考察了温度和pH对酶促反应 影响,同时考察了粗酶的热稳定性和pH稳定性。 结果表明,菌株95号所产单宁酶最适反应温度为50 ℃,该酶在30 ℃、40 ℃、50 ℃水浴 保温4 h,相对酶活80%以上,具有较好的热稳定性;最适反应和最稳定pH均为6.0,在pH 3.0～7.0之间均有较高的酶活,表示其具有 较广的pH值稳定性。     

Effects of nisin concentration on properties of gelatin film-forming solutions and their films

The addition of nisin into a gelatin matrix can change properties of the film. The aim of this work was to develop gelatin-based films containing different nisin concentrations in order to study their influence on the film's antimicrobial and physical properties and their rheological properties as a film-forming solution (FFS). The FFS was characterised by rheological assays, and the gelatin-based active films were characterised and assessed by the effects of nisin concentrations on their various properties, including antimicrobial activity. Nisin's concentration affected not only its viscoelastic properties of FFS but also its film solubility in water, film surface roughness and light barrier. The addition of nisin also slightly modified the water contact angle and the mechanical properties of the gelatin films. Finally, the films demonstrated activity against Staphylococcus aureus and Listeria monocytogenes at concentrations above 56 mg of nisin g⁻¹ of gelatin.     

豌豆蛋白乳化性及其改善研究进展

豌豆蛋白是一种营养价值较高的植物蛋白,具有来源广、成本低、致敏性低、氨基酸比例均衡等优点.乳化性是蛋白的一种重要的性质,天然豌豆蛋白乳化性较差,限制了其在食品工业中的应用,因此需要采用合适的方法对其进行改性.目前,常用于改善豌豆蛋白乳化性的方法为物理、化学和酶法.该文介绍了豌豆蛋白的组成和乳化性,并重点介绍了3种不同改...     

洋甘菊多糖的分离纯化、性质结构及抗氧化活性分析

对热回流提取得到的洋甘菊多糖进行了分离纯化,并对得到的多糖的性质结构及抗氧化活性进行分析。经处理后的洋甘菊多糖先后利用DEAE-Sepharose和Sephadex G-100柱色谱分离纯化得到了2种均一多糖(MCP-1-1和MCP-2-1);经测定2种均一多糖总糖含量分别为82.23%、84.09%,糖醛酸含量分别为4.11%、5.38%,蛋白质含量分别为0.58%、1.05%,溶解度分别为98.36%、98.44%,分子质量分别为30902、7244 Da;单糖组成实验结果表明MCP-1-1是由鼠李糖(Rha)、葡萄糖醛酸(GlcA)、半乳糖(Gal)、葡萄糖(Glc)、木糖(Xyl)和阿拉伯糖(Ara)6种单糖组成,MCP-2-1是由GlcA、Gal、Glc、GalA、Xyl和Ara六种单糖组成,2种均一多糖均是不含三螺旋结构的酸性多糖,均含有吡喃环和β-糖苷键,MCP-1-1含有α-糖苷键;2种均一多糖具有良好的热稳定性。体外清除自由基试验结果显示MCP-1-1和MCP-2-1对DPPH自由基和·OH均有清除作用,而且清除能力与均一多糖的质量浓度正相关,MCP-2-1对2种自由基的清除能力明显高于MCP-1-1。研究结果表明,分离纯化得到的洋甘菊多糖可作为天然抗氧化剂,用于食品和化妆品中。     

Wheat gluten–based coatings and films: Preparation,properties, and applications

Effective food packaging that can protect foodstuffs from physical, chemical, and biological damage and maintain freshness and quality is essential to the food industry. Wheat gluten shows promise as food packaging materials due to its edibility, biodegradability, wide availability, low cost, film-forming potential, and high resistance to oxygen. The low mechanical properties and poor water permeability of wheat gluten coatings and films limit their wide applications; however, some inferior properties can be improved through various solutions. This work presents a comprehensive review about wheat gluten–based coatings and films, including their formulation, processing methods, properties, functions, and applications. The mechanical and water resistance properties of coatings and films can be reinforced through wheat gluten modification, combinations of different processing methods, and the incorporation of reinforcing macromolecules, antioxidants, and nanofillers. Antioxidants and antimicrobial agents added to wheat gluten can inhibit microbial growth on foodstuffs, maintain food quality, and extend shelf life. Performances of wheat gluten–based coatings and films can be further improved to expand their applications in food packaging. Current research gaps are identified. Future research is needed to examine the optimal formulation and processing of wheat gluten–based coatings and films and their performance.     

芭蕉芋交联淀粉的制备工艺及糊化特性

以芭蕉芋淀粉为原料,三偏磷酸钠为交联改性剂,对芭蕉芋淀粉进行交联反应制备出芭蕉芋交联淀粉。采用正交实验设计进行制备工艺的优化,以淀粉糊化特性中的崩解值和水合特性中的膨胀力为指标,结果表明：当三偏磷酸钠用量为淀粉质量分数的0.7%,反应温度45℃,反应时间1.5h,反应pH值为9.50时,淀粉的交联效果最好。还考察了三偏磷酸钠的用量、反应pH值、反应温度、反应时间对芭蕉芋交联淀粉糊化特性的影响。     

自熄性棉织物的喷涂辅助层层自组装法制备及其阻燃性能

为赋予棉织物高效阻燃的特性,采用喷涂辅助层层自组装技术在棉织物表面将3-氨基丙基三乙氧基硅烷、海藻酸钠和聚磷酸铵构筑三元复合涂层.借助扫描电子显微镜、热重分析、垂直燃烧和微型燃烧量热仪等研究了棉织物在涂层处理前后的表面形貌、燃烧性能和热降解性能.结果表明:经涂层处理棉织物可实现离火自熄,其极限氧指数最大可达35.7％,...     

涤纶/蚕丝机织心脏瓣膜的制备及其性能

为研制具有优良力学性能和抗血液渗透性能的人工心脏瓣膜,采用涤纶(PET)长丝和脱胶蚕丝(SF),选取不同组织结构、纱线线密度和织物经纬密等参数,在小型织机上通过优化设计试验制备了PET/SF机织人工心脏瓣膜织物(AHVF),并探讨对人工瓣膜的定制化设计。结果表明:制备的AHVF的厚度小于(0.52±0.1) mm,具有良好的亲水性,水接触角为60°±1.2°,接近于自体心脏瓣膜;AHVF的力学性能具有各向异性特征,经向弹性模量为60~100 MPa, 经向断裂强度为20~40 MPa,纬向弹性模量为7~50 MPa,纬向断裂强度为7.5~20 MPa,水渗透性低于300 mL/(cm ²·min),达到了心脏瓣膜的标准,具备作为心脏瓣膜的可能。     

基于ABAQUS的筒状纬编针织物拉伸力学性能模拟

为更好地了解筒状纬编针织物抵抗拉伸变形的能力,基于对织物试样尺寸测量得到的几何结构参数,借助Rhino 3D建模软件建立了纬编针织物线圈模型和筒状纬编针织物模型;同时利用有限元分析软件ABAQUS在单位线圈和筒状织物2个方面研究了筒状纬编针织物的纵向拉伸性能;对织物拉伸过程进行有限元模拟和实验验证,并对针织物拉伸过程中...     

加水温度对莜麦面团水分分布状态和质构特性的影响

烫熟是莜麦传统特色食品制作的重要步骤,对产品品质影响显著.利用低场核磁共振技术得到莜麦面团的水分分布状态,采用食品物性仪测得莜麦面团的质构特性参数,研究了加水温度对莜麦面团水分分布状态和质构特性的影响.结果表明:当加水温度由70 ℃升高至90 ℃时,莜麦面团中弱结合水和自由水与底物的结合程度增加,弱结合水向自由水方向迁...