人造奶油的热熔性与组成结构的关系研究

本文对人造奶油申油脂成分的性质(熔点、碘价、反式酸含量和脂肪酸组成)进行了测定,并用差示扫描量热法(DSC)研究脂肪的熔化性质。研究结果表明,DSC曲线能确切地反映人造奶油的口熔性、热稳定性与流变性。通过改变油脂的组成结构可以改变油脂的熔化性质,因此在人造奶油生产中可以用DSC曲线进行质量控制。     

纤维级聚酯黑色色母粒的热性能

通过双螺杆挤出机制备纤维级聚酯黑色色母粒,并对其进行示差扫描量热分析(DSC)、热重分析(TGA)、流变性等性能表征和测试.结果表明:随着颜料炭黑含量的增加,色母粒的玻璃化温度和熔点稍有降低,结晶温度下降显著,色母粒的热稳定性提高,色母粒的熔融流动性能变差.     

十八烷基聚甲基丙烯酸甲酯相变微胶囊的制备及其表征

以聚甲基丙烯酸甲酯(PMMA)为壁材,十八烷(C18)为芯材,采用悬浮聚合法制备相变微胶囊,探讨了乳化剂用量、乳化转数、芯壁质量比m(C18)∶m(PMMA),对相变微胶囊的粒径大小、表面形貌及热学性能的影响,并对微胶囊的化学结构与晶体结构、热稳定性、热循环性以及致密性进行了表征与分析。研究结果表明：以乳化剂质量分数4.8%、乳化转数速3 000 r/min、芯壁质量比m(C18)∶m(PMMA)1∶1制备的相变微胶囊相变温度为24.7℃,相变潜热为169.13 J/g,储能效率E_es为76.4%、包覆率E_en为79.78%、储热能力C_es为95.76%,具有较高的热焓值以及优秀的循环稳定性,有望用于智能调温纺织品的制备原料。     

复合共纺长丝原料CDP、PET熔体的流变性和热稳定性

论述了阳离子改性聚酯和常规聚酯的熔体流变性和热稳定性。实验是借助于双组分共轭流变仪、乌氏粘度计及热分析仪进行的，利用双组分界面形状的变化，可直观地判断不同熔体粘度、不同温度、不同剪切速率下两种熔体粘度的差异；并对ＣＤＰ、ＰＥＴ在动态熔融状态下的熔体热稳定性做了探讨，取得了实用的结果，为纺丝工艺参数的设定提供了依据     

嗜热α-淀粉酶热稳定性的决定因素及提高策略

阐明了嗜热α-淀粉酶的微生物来源及性质,分析了影响嗜热α-淀粉酶热稳定性的8种因素,提出采用物理法、化学法和生物法提高嗜热α-淀粉酶热稳定性的策划,为完善α-淀粉酶的热稳定化技术提供了参考依据。     

PP/PEST共混物的性能研究

以聚丁二酸乙二醇-共-对苯二甲酸乙二醇酯(PEST)为添加剂,聚丙烯接枝甲基丙烯酸缩水甘油酯(PP-g-GMA)为相溶剂,利用双螺杆挤出机对聚丙烯(PP)进行熔融共混改性.通过扫描电子显微镜、示差扫描量热法、热重分析法和旋转流变仪等方法,对PP/PEST共混物分散相的形貌、结晶性能、热性能、流变性等进行了测试.结果表明:PP-g-GMA的添加能使PP/PEST共混物中分散相PEST的粒径大小和分布得到一定的改善;PEST的加入使共混物的结晶能力较纯PP有所下降;受PEST热稳定性较差的影响,共混物的热稳定性也有一定程度的下降;共混物的复数黏度介于两单组分的复数黏度之间,呈现切力变稀现象.     

差示扫描量热法测定奶粉的热稳定性

以差示扫描量热法对全脂奶粉、脱脂奶粉、全脂甜奶粉及中老年奶粉的热稳定性进行了研究,运用Ozawa和Kissinger方程求得各种奶粉的活化能,比较了这几种不同成分的奶粉的热稳定性,分析了奶粉成分对奶粉热稳定性的影响。结果表明,热稳定从高到低的顺序依次为脱脂奶粉、全脂奶粉、中老年奶粉、全脂甜奶粉,并且牛乳脂肪、植物油、蔗糖会降低奶粉的热稳定性。     

纳米纤维素晶体的制备方法及其在制浆造纸中的应用前景

阐述了纳米纤维素晶体的两种制备方法:无机酸水解法和纤维素酶水解法,简要介绍了它的性质,包括形状及尺寸分布、结晶度、强度、热稳定性、触变性与流变性等。总结了其在制浆造纸以及纳米复合材料中的应用情况。     

苦丁茶冬青叶多糖KPS IIIa的热分析研究

采用热重、热重-红外联用及差示扫描量热法研究苦丁茶冬青叶多糖KPSⅢa的热稳定性。结果表明,苦丁茶冬青叶多糖在225℃以下只失去吸附水,在225～625℃间发生剧烈的裂解反应,产生水和二氧化碳;与肝素、淀粉、半乳糖及甲壳素的热分析比较,含有硫酸酯的苦丁茶冬青叶多糖和肝素的热稳定性较低,含氨基的甲壳素的热稳定性最好。说明苦丁茶冬青叶多糖在225℃以下相对稳定,不同的基团对多糖的热稳定性有很大影响。     

棒状氧化锌对聚甲基丙烯酸甲酯的改性

为改善聚甲基丙烯酸甲酯(PMMA)的性能,棒状氧化锌(ZnO)经硅烷偶联剂表面改性后,与PMMA溶液共混,得到ZnO/PMMA复合材料.对该复合材料的热性能、光学性能以及溶解性能进行测试.研究发现,加入棒状ZnO可提高PMMA的热性能、紫外屏蔽能力和耐溶剂性能.随着ZnO质量分数的增加,基体的最大分解温度逐渐提高;复合材料在紫外光区的吸收率显著增大,而可见光区透光率基本不变;复合材料的耐有机溶剂性能得到提高.     

Starch-based noodles: Current technologies,properties, and challenges

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.     

丹蒽醌对氧化脱胶苎麻纤维理化性能的调控

为解决苎麻氧化脱胶中纤维容易被过度氧化而性能受损的问题,在氧化脱胶液中添加了具有纤维素和半纤维素保护效果的试剂 1,8-二羟基蒽醌（丹蒽醌）,并通过调节1,8-二羟基蒽醌的用量实现了对苎麻纤维理化性能（强伸性能、聚合度、半纤维素含量、制成率等）的调控。结果表明,1,8-二羟基蒽醌用量越高,纤维中半纤维素含量、制成率越高;但纤维强伸性能随1,8-二羟基蒽醌含量先升高后降低;当1,8-二羟基蒽醌的用量为2 %时,脱胶的综合效果最佳,此时纤维的断裂功、聚合度、半纤维素含量、制成率比不使用1,8-二羟基蒽醌时分别提高了41.0%、2.0%、17.3%、7.0%;此外,使用1,8-二羟基蒽醌后,脱胶废水的COD值降低了40%,大幅度提高了氧化脱胶工艺的环保性。     

Dietary taurine reduces zinc-induced toxicity in male Wistar rats

Taurine is an agent for treating the heavy metal intoxication and presence of metals such as zinc, copper, and iron may have a role in heavy metal toxicity, a study was undertaken to investigate the effect of taurine on the toxicity of zinc in male Wistar rats. The rats were divided into 8 groups and fed different diets with or without supplement of 5% taurine and 150 to 600 ppm zinc for 2 mo. It was found that the body weight of rats, the ratios of liver and kidney weight to body weight, and the level of glutathione in the liver were decreased with increasing the dose of zinc. The levels of zinc in the liver, kidney, and plasma, the levels of malondialdehyde in the plasma, the levels of thiobarbiture acid-reactive substances in the liver, the activities of aspartate transaminase, alanine transaminase in the plasma, the levels of blood urea nitrogen and creatinine in the plasma of rats were increased with the increasing dose of zinc. Hence, symptoms of zinc toxicity in rats included loss of body weight, hepatotoxicity, and nephrotoxicity. However, these toxic effects of zinc were significantly reduced when the rats fed diet with supplement of taurine. Furthermore, the level of zinc in the feces of rats treated with taurine and zinc was higher than that of rats treated with zinc alone. It indicated that taurine thereby leading to a decreased absorption of dietary zinc and promoted excretion.     

乙烯基类聚合物鞣剂共单体种类配比与应用性能相关性的研究

采用单因素二次回归正交试验研究了乙烯基类聚合物鞣剂共单体种类、配比与应用性能的相关性,通过比较不同共单体及其不同配比的乙烯基聚合物鞣剂复鞣革样与对比革样的性能,得到了不同共单体对鞣剂应用性能的贡献。结果表明：含极性基团的共单体有利于复鞣革样抗张强度、耐湿热稳定性的提高,但影响革样的柔软性和革样胶原纤维的柔韧性;共单体丙烯酰胺对复鞣革样的丰满性具有特殊的贡献,鞣剂分子中引入丙烯酸酯类共单体有利于复鞣     

纺纱牵伸胶辊胶圈应用技术概要

阐述棉纺牵伸胶辊、胶圈的应用技术和牵伸原理,重点探讨了胶辊、胶圈的牵伸工艺特性及其合理配置、胶辊制作、周期管理、质量管理、使用管理、产品缺陷与其机械波分析、纺纱环境和挡车工操作水平对纺纱性能的影响,提出胶辊、胶圈有关机件的质量要求等。     

Effect of Compositional Variation of Gluten Proteins and Rheological Characteristics of Wheat Flour on the Textural Quality of White Salted Noodles

Protein quality parameters of wheat flour, as well as protein content, showed significant relationship with hardness, cohesiveness, springiness, adhesiveness, chewiness, and gumminess of the cooked noodles. A significant positive correlation (0.54) was observed between glutenins and hardness of noodles. Chewiness of the noodles increased with the protein content, sodium dodecyl sulfate sedimentation volume, dough development time, dough stability, and glutenins. Hardness, springiness, cohesiveness, gumminess, and chewiness of the noodles were negatively affected by gliadin to glutenin ratio. Multiple regression analysis depicted significant relationships of the various noodle quality parameters with wheat flour characteristics. The results revealed that the relative composition of the gliadins and glutenins had a considerable effect on the textural profile of noodles indicating their defining contribution on the noodle quality. The resulting information could be useful in predicting the noodle-quality potential of the varieties.     

Effect of common and new gums on the quality,physical, and textural properties of bakery products: A review

Hydrocolloids (gums) have a good functional characteristic such as emulsifying, gelling, solubility, and textural improvement. In the bakery products, hydrocolloids were used to improving dough performance, bread and cake characteristics, sensorial quality, and extension the products shelf life. Several studies reported the potential use of hydrocolloids in breads, biscuits, cakes, and pasta formulation. The present review summarized the effect of the most common and new hydrocolloids (xanthan, guar, Arabic, carrageenan, karaya, alginate, acacia, methylcellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, locust bean, balangu seed, wild sage seed, basil seed, and cress seed gums) on the rheological, physicochemical, textural, and quality characteristics of bakery products. Gums addition improved volume and porosity of the breads and cakes. Gums influence on the gelatinization and retrogradation of starch and decreased the retrogradation of starch. In the bakery products, hydrocolloids were used to improving mixing and increasing the shelf life of the products through moisture preservation and avoidance of syneresis in some frozen foods. This study summarized the influence of the most common and new hydrocolloids on the rheological, physicochemical, textural, and quality characteristics of bakery products. Addition of seeds gum to the breads, biscuits, cakes, and pasta formula led to an increase in the viscosity of the batter. Also, the firmness of bakery products showed that they became softer with increasing gum levels.     

纸质文献保存和修复方法专利技术综述

通过对纸质文献保存和修复领域专利技术文献的收集、分析、标引和梳理,分析了该领域专利技术分布及专利申请情况,分别探析了脱酸、修补、加固、装裱4种技术的专利技术演进路线,最后对该领域专利技术进行了总结。     

Effects of process parameters on quality changes of shrimp during drying in a jet-spouted bed dryer

ABSTRACT:  The objective of the present study was to investigate the effects of various parameters, that is, concentration of salt solution (2%, 3%, 4%[w/v]), boiling time (3, 5, 7 min), drying air temperature (80, 100, 120 °C), and size of shrimp, on the kinetics of drying and various quality attributes of shrimp, namely, shrinkage, rehydration ability, texture, colors, and microstructure, during drying in a jet-spouted bed dryer. In addition, the effects of these processing parameters on the sensory attributes of dried shrimp were also investigated. Small shrimp (350 to 360 shrimp/kg) and large shrimp (150 to 160 shrimp/kg) were boiled and then dried until their moisture content was around 25% (d.b.). It was found that the degree of color changes, toughness, and shrinkage of shrimp increased while the rehydration ability decreased with an increase in the concentration of salt solution and boiling time. Size of shrimp and drying temperature significantly affected all quality attributes of dried shrimp. The conditions that gave the highest hedonic scores of sensory evaluation for small dried shrimp are the concentration of salt solution of 2% (w/v), boiling time of 7 min, and drying air temperature of 120 °C. On the other hand, the conditions that gave the highest hedonic scores of sensory evaluation for large dried shrimp are the concentration of salt solution of 4% (w/v), boiling time of 7 min, and drying air temperature of 100 °C. The quality attributes of dried shrimp measured by instruments correlated well with the sensory attributes, especially the color of dried shrimp.     

Alleviating bottlenecks in a microbiology laboratory

This paper presents the application of Operational Research methodology to the logistics of food testing at a microbiology laboratory. Firstly, bottleneck analysis is used to identify the two most crucial, of the eight, stages. The two bottleneck stages, of sample pipetting and agar distribution into Petri dishes, are then subjected to special purpose scheduling analyses. The scheduling algorithms are each illustrated without undue technical detail. Reversal in the priority order of sample pipetting and the, related, plate labelling process, results in a 22% efficiency gain. Similarly, co-ordination of the production schedule of the agar in which the samples are grown, with the test sample sequence, substantially reduces agar requirement and wastage. The overall effect on the entire process is to allow continuous testing throughout the day and an increase in the capacity of the laboratory of over 20%, with no additional staff or capital investment.