棉/丝光羊毛/Outlast纤维混纺纱的性能

为研究Outlast纤维含量对棉/丝光羊毛/Outlast混纺纱热性能的影响,采用差示扫描量热仪对其进行测试分析。结果表明,Outlast纤维的含量对相变调温的起止温度、峰值温度影响较小。在降温过程中终止温度和峰值温度随Outlast纤维含量的增加逐渐降低。混纺纱降温时的相变热焓值与Outlast纤维含量之间呈显著线性关系,升温时混纺纱的相变热焓值与Outlast纤维含量的线性关系没有降温时显著。在Outlast纤维含量为40%时,混纺纱的热焓值和相变起止点的温度都相对较好。     

明胶溶液浓度对凝胶体质构特性与凝胶特性的影响研究

文章应用质构仪建立了明胶溶液凝胶体质构特性的评价方法，除了凝冻强度之外，还创新性地首次引入了凝胶破裂时的凝胶强度、坚实性、硬度及弹性等评价指标，指导外界刺激条件下凝胶破裂前凝胶特性的评价。另外，配制1%～10%质量分数的明胶溶液，分别应用质构仪、流变仪及差示扫描量热仪研究了不同浓度对明胶溶液凝胶体的质构特性、升温过程中的凝胶-溶胶转化温度与吸热焓，以及明胶溶液降温过程中的溶胶-凝胶转化温度。结果表明：明胶溶液浓度明显影响凝胶体的质构特性与凝胶特性，同时也影响明胶溶液升降温过程中的凝固温度与熔融温度。凝冻强度、凝胶强度、坚实性、硬度及凝胶-溶胶转化温度、溶胶-凝胶转化温度均随浓度增加出现明显增大，而且与浓度之间存在高度相关性。弹性与弹性模量总体趋势上亦随着溶液浓度的增加而增大，而且在升降温过程中明胶溶液的弹性模量变化表现出明显的物理凝胶特性。     

氯化钠添加量对鱼皮明胶凝胶性能和结构的影响

以罗非鱼鱼皮为原料制备鱼皮明胶,通过单轴压缩实验、差示扫描量热实验(DSC)和红外光谱法(FT-IR)探讨了不同氯化钠添加量(0、0.5%、1.0%、1.5%、2.0%、3.0%,w/v)对不同浓度鱼胶凝胶样品(2%、4%、6.67%,w/v)的真实应力、杨氏模量、热焓值和结构的影响。结果表明,随着鱼胶浓度增加其真实应力和杨氏模量显著增加,表明鱼胶的凝胶强度和硬度显著增加,添加氯化钠后,鱼胶体系的凝胶强度和硬度随氯化钠添加量的增加呈现显著下降趋势,当氯化钠添加量达到3%时,鱼胶凝胶强度和硬度的值最小。差式扫描量热量热分析结果表明,随着氯化钠浓度的增加,热焓值下降,鱼胶的凝胶网络交联程度变弱。傅里叶变换红外光谱分析结果表明,随着氯化钠添加量增加,酰胺Ⅰ带吸收峰逐渐向低波数方向移动,氢键形成受到抑制,鱼胶凝胶强度降降低。研究表明氯化钠的存在破坏了鱼胶凝胶样品的空间结构,降低了鱼胶的凝胶性能。     

微胶囊相变调温纤维的调温性能研究

文章采用差示扫描量热法测定相变微胶囊的吸热焓及放热焓;采用温度变化曲线法测定微胶囊相变调温纤维的升温及降温过程;从而研究相变微胶囊及相变微胶囊调温纤维的调温性能。结果表明:以石蜡为芯材的相变微胶囊满足纺织用相变材料的要求;粘胶基相变微胶囊调温纤维的温度调控范围与其采用的相变微胶囊的吸热和放热温度区间一致。     

用差示扫描量热法测定调温针织物的热性能

介绍了差示扫描量热法（DSC）的原理、用途及用法,测定了罗纹空气层织物的相变温度和相变焓,得到了其DSC曲线图。结果表明该织物具有良好的温度调节功能。     

木薯变性淀粉对猪肉肌原纤维蛋白凝胶质构、流变及热力学特性的影响

本实验研究了不同比例的木薯变性淀粉对猪肉肌原纤维蛋白(MP)凝胶特性的影响。分析了凝胶质构、静态流变和热力学特性的变化。结果显示:添加10%的木薯变性淀粉增加了蛋白凝胶的弹性,而凝胶的硬度、强度、内聚性、咀嚼性和胶黏性相对适中,从而改善凝胶的质构特性;通过差示扫描量热仪(Differential scanning calorimetry,DSC)分析发现木薯变性淀粉添加量为10%时,降低了蛋白的热相变温度和焓值,促进蛋白变性;另外,木薯变性淀粉的添加也改变了凝胶的表观粘度及触变环面积。当木薯淀粉添加量为10%时,凝胶的表观粘度和触变环面积最小,改善了凝胶的塑性能力及流变稳定性。     

差示扫描量热仪及流变仪研究k-卡拉胶的凝胶特性

应用旋转流变仪及差示扫描量热仪(DSC)研究了1.5%k-卡拉胶溶液(质量浓度)的水凝胶与钾凝胶的凝胶特性,分别从溶胶温度、凝胶温度、熔融焓、结晶焓及弹性模量等指标进行考察。结果表明:k-卡拉胶水凝胶的溶胶温度高于凝胶温度,钾凝胶的溶胶温度却低于凝胶温度;溶胶时弹性模量值明显高于凝胶时弹性模量。增加钾离子提高溶胶温度与溶胶时弹性模量,同时使凝胶温度增加,增加的幅度明显大于溶胶温度的增加幅度,而凝胶时弹性模量却低于水凝胶发生凝胶时的弹性模量。DSC结果表明水凝胶与钾凝胶溶胶温度均高于凝胶温度,水凝胶溶胶时热焓值低于凝胶时热焓值,而钾凝胶溶胶时热焓值高于凝胶时热焓值。钾凝胶相比于水凝胶,吸热熔化与结晶温度增加,熔融与结晶时热焓值亦相应出现增加。不同批次k-卡拉胶溶液的水凝胶与钾凝胶特性存在差异,特别是凝胶-溶胶转化时的弹性模量存在明显差异。水凝胶DSC曲线中吸热峰与放热峰的峰宽存在明显差异性,而钾凝胶发生熔融时峰宽均大于凝胶时结晶峰的峰宽。     

鸡骨明胶的凝胶化研究

本研究采用差示扫描量热法(DSC)、红外光谱(FT-IR)、圆二色谱(CD)、荧光光谱、原子力显微镜(AMF)等手段研究鸡骨明胶溶液胶凝化过程.原子力显微镜观察到,随着明胶溶液中分子数目的增多,分子链逐渐聚集缔合形成网络结构.圆二色谱显示,明胶凝胶的交联点为类似胶原的三股螺旋结构.明胶溶液胶凝时,体系的荧光强度显著增大,红外光谱可见O-H和C=O伸缩振动增加.由此推断,明胶的凝胶化是明胶分子借助氢键力作用形成三股螺旋交联点的网络结构,同时疏水相互作用促进凝胶形成.     

PET,PBT纤维混合物的DSC定性定量分析研究

利用差示扫描量热法(DSC)分别测定了PET纤维、PBT纤维及两者混合物的DSC曲线,通过比较他们各自的特点与两者之间的差异,对两种纤维进行了定性分析。同时研究了热效应峰的热焓与样品组成的线性关系,建立了PET纤维和PBT纤维混合物的定量分析函数模型。试验表明,差示扫描量热法可以准确有效地对PET纤维和PBT纤维进行定性定量分析。     

高级脂肪醇类相变储能微胶囊合成响应面优化

采用原位聚合方法制备了一种高级脂肪醇类相变储能微胶囊,对其工艺进行了分析。对微胶囊形成具有重要影响的乳化剂用量、体系p H值和相变材料投料量进行了响应面优化,并对优化后产物采用扫描电子显微镜和差示扫描量热分析进行了表征。结果表明:最优聚合工艺为乳化剂用量相对相变材料质量分数为4.8%,体系p H值为5.5,相变材料投料质量分数为75.000%,此时微胶囊的包覆率达到66.00%;扫描电子显微镜显示其成形良好,粒径较均匀;差示扫描量热测试显示其相变焓为78.93 J/g。     

Rheological properties of channel catfish (Ictalurus punctaus) gelatine from fish skins preserved by different methods

Gelatins were extracted from channel catfish skins preserved by different methods using 50 mmol/l acetic acid. Molecular weight distribution, gel strength and viscoelastic properties of gelatin samples were studied. Compared to gelatins from fresh and frozen skins, gelatin from dried channel catfish skin exhibited higher gel strength. This can be explained by the large α-chains content of gelatin from the dried skins. The gelling point and melting point of dried channel catfish skin gelatin solution were similar to those of fresh skin gelatin solution, but distinctly different from those of frozen skin gelatin. After maturation at low temperature, melting points of gelatins increased. But the melting point of frozen skin gelatin was still the highest among the three gelatin samples studied.     

提取pH对鳙鱼鱼鳞明胶功能性质的影响

研究了制备过程中pH值(3.0~7.0)对鳙鱼鱼鳞明胶组成、得率和功能性质(凝胶强度、胶融温度和浊度)的影响,并对鱼鳞明胶的分子量分布进行了探究。结果表明,pH值在3.0~7.0时均能得到高品质的鱼鳞明胶(高蛋白质含量、低灰分含量)。随着pH值的增加,鳙鱼鱼鳞明胶得率逐渐降低,浊度逐渐增加,凝胶强度和胶融温度先增加后减小。此外,鳙鱼鱼鳞明胶的凝胶强度与分子量分布具有一定的相关性。上述研究结果可为特定用途的鱼明胶制备提供技术支撑。     

Ultraviolet irradiation improves gel strength of fish gelatin

Preliminary studies were undertaken to investigate the impact of ultraviolet (UV) irradiation on the gel strength, viscosity, and thermal properties of a commercially procured fish gelatin sample. Fish gelatin samples (dry granules) were exposed to UV irradiation for 30 and 60 min. Irradiated samples exhibited significant improvement in the gel strength, marked reduction in viscosity, with significant changes in the melting enthalpy. Results indicated the prospects of employing UV radiation as an alternative method over conventional means for improving some of the quality attributes of fish gelatin.     

提取温度对罗非鱼皮明胶理化性质的影响

本研究以罗非鱼皮为原料,研究在不同温度(30、40、50、60、70、80、90℃)下提取的明胶所表现的得率、凝冻强度、聚丙烯酰胺凝胶电泳分析、傅里叶红外光谱分析、热变性温度、流变性性能等理化特征。结果表明,提取温度对鱼皮明胶的紫外吸收无明显影响;随着提取温度的升高,鱼皮明胶的得率逐渐增大,在提取温度为60~80℃时差异不显著(p>0.05),在90℃达到最大值(62.60%±0.84%);聚丙烯酰胺凝胶电泳图谱显示,较低温度(30、40、50℃)下提取的鱼皮明胶由α₁、α₂、β 3条肽链组成,提取温度升高后电泳条带强度降低;提取温度为50℃时,罗非鱼皮明胶的凝冻强度最大,高达(884.33±26.76)g;FTIR光谱显示,不同温度下提取的鱼皮明胶在酰胺区都具有特征吸收峰,在光谱中显示出微小的差异;不同温度下提取的鱼皮明胶的热变性温度分别为(101.05±2.97)、(104.35±3.54)、(107.59±0.37)、(97.80±4.21)、(95.35±2.60)、(92.52±3.15)、(89.66±1.23)℃;提取温度通过改变明胶的分子量大小影响明胶溶液内部贮藏能量的多少,进而对明胶溶液的流变性能产生影响。     

不同品种鹰嘴豆淀粉糊与凝胶特性研究

以不同品种的鹰嘴豆Kabuli和Desi为原料,采用快速黏度仪、质构仪和流变仪研究淀粉糊与凝胶特性的差异。研究表明:Kabuli淀粉在糊化过程中的峰值、谷值、最终黏度等特征值均高于Desi淀粉,而降落值、回值及成糊温度却低于Desi淀粉。Kabuli淀粉的品质优于Desi淀粉,但这2种鹰嘴豆淀粉糊的糊丝均属于短糊系列。在不同热过程中Desi淀粉形成凝胶速度快,强度大;Kabuli淀粉的凝胶强度随温度的变化是可逆的。Kabuli淀粉凝胶破裂强度、弹性模量均小于Desi淀粉凝胶。     

Comparison of gelling properties and flow behaviors of microbial transglutaminase (MTGase) and pectin modified fish gelatin

The gelling and structural properties of microbial transglutaminase (MTGase) and pectin modified fish gelatin were compared to investigate their performances on altering fish gelatin properties. Our results showed that within a certain concentration, both MTGase and pectin had positive effects on the gelation point, melting point, gel strength, textural, and swelling properties of fish gelatin. Particularly, low pectin content (0.5%, w/v) could give fish gelatin gels the highest values of gel strength, melting temperature, and hardness. Meantime, flow behavior results showed that both MTGase and pectin could increase fish gelatin viscosity without changing its fluid characteristic, but the latter gave fish gelatin higher viscosity. Both MTGase and pectin could increase the lightness of fish gelatin gels but decreases its transparency. More importantly, fluorescence and UV absorbance spectra, particle size distribution, and confocal microscopy results indicated that MTGase and pectin could change the structure of fish gelatin with the formation of large aggregates. Compared with MTGae modified fish gelatin, pectin could endow fish gelatin had similar gel strength, thermal and textural properties to pig skin gelatin.     

鱼鳞明胶的提胶工艺

根据单因素试验结果,利用正交试验,考察了提胶温度、pH值和时间对鱼鳞明胶品质的影响。并得到提胶条件为:提胶温度为55℃,pH值为6,时间为5h。在该条件下明胶的提取率达到58%,6.67%的明胶溶液在60℃时的黏度为8.16mPa·s,7℃下保温18h后凝胶强度为1 202.65g,约290Bloom,凝胶温度和熔化温度分别为20.8℃,26.9℃,等电点约为pH 7,可达到高品质明胶的要求。     

Extraction and properties of gelatin from channel catfish (Ietalurus punetaus) skin

Response surface method was used to determine the optimum operating conditions for extracting the gelatin from channel catfish skin. The optimal conditions for maximum gel strength are 68.8 h for the time of treatment with calcium hydroxide solution, 43.2 °C for the extraction temperature, 5.73 h for the extraction time with hot water. The gelatin from channel catfish skin showed a high gel strength, 276±5 g. Compare to porcine skin gelatin, the gelatin from channel catfish skin has different amino acids composition and a lower thermo-stability.