A comparative study on hygroscopic and physiochemical properties of chicken powders obtained by different drying methods

Abstract

Different drying methods (spray drying (SD), vacuum drying (VD), microwave vacuum drying (MVD), and infrared vacuum drying (IFVD)) were applied in order to compare the hygroscopicity behavior of chicken powders. The hygroscopicity curves and glass transition temperature were used to evaluate the influence of ambient humidity and temperature on moisture absorption of powders. The results showed that the chicken powder dried by MVD had the lowest moisture absorption, followed by IFVD, VD, and SD. The hygroscopicity of SD chicken powders was different from other three kinds of chicken powders due to the physical properties of particles and the changes of protein secondary structure as detected by the Fourier transform-infrared spectrometer. For the three vacuum drying methods, the difference of protein secondary structure was the main reason of differences in hygroscopicity. Although MVD chicken powders were slightly inferior to SD chicken powders in taste, MVD chicken powders were the best in terms of smell and color as suggested by instrumental sensory parameter evaluations. It was found that MVD had a positive effect on reducing moisture absorption and maintaining sensory quality of chicken powders.     

功能性皮芯型复合纤维

设计并纺制了一种以自制的吸湿性能优良的共聚醚酯(A)为芯层,以COPET(B)为皮层的新型皮芯复合纤维。该纤维具有良好的吸湿性、抗静电性和可染性。用相同材料纺制成偏心型皮芯复合纤维,还可赋予纤维永久卷曲的功能。     

涤纶仿真丝面料的开发及其服用性能探讨

采用83.3 dtex/72f涤纶三叶有光丝制成仿真丝面料,对面料进行碱减量处理和低温等离子处理,并对面料服用性能进行了测试.结果表明经过低温等离子处理的涤纶仿真丝面料具有良好的抗皱性、吸湿透气性和染色性能,具有超真丝的效果.     

膨润土的性质及其在食品工业中的应用

本文通过叙述膨润土的物理、化学和理化性质,简要地介绍了膨润土在食品工业中的重要用途。     

利用κ-Köhler理论研究大气气溶胶的吸湿特性

利用κ-K?hler理论对西安、北京两地大气气溶胶体系的吸湿特性进行研究。选取多种代表性无机物（硫酸盐、硝酸盐、氯盐）及有机物（烯烃、芳香烃、羧酸）建立气溶胶体系模型，使研究体系更接近于真实大气成分。结果表明，在空气质量由清洁状态向雾霾发生状态转变的过程中，两种体系中均呈现有机物含量逐渐减少而(NH₄)₂SO₄和NH₄NO₃含量逐渐增多的趋势，这种变化趋势总是促使气溶胶体系整体吸湿能力增强，因此更易吸湿增长形成雾霾。对体系中不同组分对吸湿性的影响进行了定量预测，理论预测的变动趋势与实际观测的变动趋势相同，揭示了雾霾形成过程中各组分的变动趋势及影响程度，为针对性解决雾霾问题提供思路。     

Effect of nitrogen–phosphorus fire retardant blended with Mg(OH)2/Al(OH)3 and nano‐SiO2 on fire‐retardant behavior and hygroscopicity of poplar

The aim of the study was to screen any possible synergistic effects related to the combination of nitrogen–phosphorus fire retardant and Mg(OH)₂/Al(OH)_3. This combination is used to improve fire performance, especially smoke suppression of poplar through ultrasonic wave impregnation after microwave treatment. In this study, nano‐SiO₂ was used to impregnate poplar treated with nitrogen–phosphorus fire retardant and form a hydrophobic layer on wood cells in order to improve hygroscopicity and reduce water uptake. Cone tests and thermal analysis showed that poplar treated with blended fire retardant had improved behavior. Results show that a 20% and 25% nitrogen–phosphorus fire‐retardant solution (blended by adding 10% Mg(OH)₂/Al(OH)₃ based on the dry weight of nitrogen–phosphorus fire retardant) was more effective for smoke suppression. The heat release rate, total heat release, and total smoke production of a 25% nitrogen–phosphorus fire‐retardant solution blended by adding 10% Mg(OH)₂/Al(OH)₃ showed significant reduction. The char residual yield showed a marked increase to 35.5%. Fourier transform infrared analysis suggested a –CH₂–Si–CH₂– and Si–O–C stretching vibration in nano‐SiO₂ treated poplar, which greatly decreased the hygroscopicity of fire‐retardant‐treated poplar. Copyright © 2014 John Wiley & Sons, Ltd.     

动态法研究ADN的吸湿性能

针对二硝酰胺铵(ADN)的强吸湿性及吸湿性研究的迫切性,建立了动态分析的新方法。采用快速分析方法研究了ADN的吸湿性能,得出了ADN的吸湿过程曲线、临界相对湿度、吸湿速率曲线。比较动态分析方法与干燥器平衡法(标准方法GJB7708-2005-404.1)结果,认为两种方法准确度等效。动态分析方法的相对标准偏差为1.45%。     

低温氩等离子体处理珍珠纤维混纺纱研究

采用常压低温氩等离子体对珍珠纤维混纺纱进行改性处理.探讨了处理时间和处理功率对纱线的失重、强力和吸湿性能的影响,实验发现纱线失重随处理时间和功率的增大而持续增大,强力先增大后降低,吸湿性能得到明显提高.     

膨胀岩相似材料水分迁移试验研究

为研究膨胀岩水分迁移规律,以石英砂、膨润土、高岭土、石膏、松香酒精溶液及水作原料,配制两种膨胀性相似材料以开展水分迁移试验研究。通过室内试验,研究了吸湿过程中膨胀岩相似材料吸湿量随时间的变化关系及水分在不同方向上的迁移规律,得到水分在材料内部的迁移特征,并探讨温度对材料水分迁移的影响。结果表明:膨胀岩相似材料靠近吸湿面的一定深度范围内含水率变化梯度较大,随着吸湿深度的增加,含水率近似呈线性规律减小,直到水分迁移深度不再变化。水分迁移的速度与材料自身的膨胀性有直接关系,不同膨胀性的岩样表现出来的水分迁移规律有较大差异。温度增加,材料的吸湿速率随之增大,且材料的最终吸湿量增大,即温度增加可以促进水分在相似材料中迁移,进而影响材料内部含水率变化。