An Electron Spin Resonance Study of Evolution of Organic Free Radicals in Irradiated Pepper During Heat Treatment

ABSTRACT: The thermal evolution behavior of the organic free radicals induced in irradiated black pepper was studied by electron spin resonance spectroscopy. To analyze the time-dependent evolution process, we used the theory of transient phenomena, that is, an ordinal differential equation, as well as the nonlinear least squares numerical method. We found that the radical evolution that occurred in the irradiated pepper obeys a single exponential function and yields a unique time constant. The evolution of the organic free radical undergoes a simple reaction process of a single radical species.     

食品中病原菌检测技术研究进展

介绍了许多食品安全检测新技术和新方法,包括生化检测技术、免疫学技术、PCR检测技术、生物芯片技术、传感器技术、流式细胞术和基因探针技术,并且阐述了食品安全检测技术的发展趋势,这些技术的发展将会在食品卫生检验方面起到越来越重要的作用,最终将达到预防肠道传染病和食物中毒发生的目的。     

使用热反应型水溶性聚氨酯F-2840E提高纯棉织物"三防"效果

通过试验验证了热反应型水溶性聚氨酯F-2840E可提高“三防”（拒水、拒油、拒污）助剂TG-410H的使用性能，可提高TG-410H等部分有机氟系“三防”整理剂的耐洗性和“三防”效果，减少了“三防”助剂的用量．     

Lactic acid production from dining‐hall food waste by Lactobacillus plantarum using response surface methodology

BACKGROUND: Food waste generally has a high starch content and is rich in nutritional compounds, including lipids and proteins. It therefore represents a potential renewable resource. In this study, dining‐hall food waste was used as a substrate for lactic acid production, and response surface methodology was employed to optimise the fermentation conditions. RESULTS: Lactic acid biosynthesis was significantly affected by the interaction of protease and temperature. Protease, temperature and CaCO₃ had significant linear effects on lactic acid production, while α‐amylase and yeast extract had insignificant effects. The optimal conditions were found to be an α‐amylase activity of 13.86 U g^?1 dried food waste, a protease activity of 2.12 U g^?1 dried food waste, a temperature of 29.31 °C and a CaCO₃ concentration of 62.67 g L^?1, which resulted in a maximum lactic acid concentration of 98.51 g L^?1 (88.75% yield). An increase in inoculum size would be appropriate for accelerating the depletion of initial soluble carbohydrate to enhance the efficiency of α‐amylase in dining‐hall food waste fermentation. CONCLUSION: A suitable regression model for lactic acid production was developed based on the experimental results. Dining‐hall food waste was found to be a good substrate for lactic acid fermentation with high product yield and without nutrient supplementation. Copyright © 2008 Society of Chemical Industry     

Establishing a System for Food Recalls to Protect Food Quality and Safety in China

There are no explicit laws concerning food recalls in China; moreover, some related regulations have weaknesses. China should first create a system of laws and regulations governing food recalls, establish a system to recall defective food, and strengthen administrative and legal remedial mechanisms related to consumer rights.     

Study on Preparation and Application of Ti／Si Complex Zeolite

A Ti/Si complex zeolite has been prepared. X-ray diffraction and infrared spectrometry study has shown that two structures, namely the ZSM-5 and MCM-41, exist in the sample. BET tests have revealed that the complex zeolite contains regular mesopores of 2.6 nm. Ultraviolet spectrometry analysis has shown that the Ti species exist in the zeolite skeleton in the form of tetra-coordinate valence. The Ti/Si complex zeolite (TS-1/Ti-MCM-41) has apparently improved catalytic activity with respect to the macromolecular organic compound oxidation as compared to individual components of either Ti or Si containing zeolites (TS-1 and Ti-MCM-41).     

Fabrication of Ormocer Containing Eu3＋ Ion and Their Optical Spectra

Eu3 ions were incorporated in sol and gel by a sol-gel processing using 3-glycidoxypropyltrimethoxysilane(CH2OCHCH2O(CH2)3Si(OCH3)3, GPTMS) and ethyl silicate (TEOS) as precursors. The basic chemical-physical properties such as DTA curve, FF-IR spectra and specific surface area were recorded. The characteristics of their optical spectra were measured and investigated. The results indicate that the emission intensity of Eu3 ion in ormocer is much higher and the global line width is wider than those in SiO2 gel. The relationship between the composition and structure of gels and the fluorescence intensity and width were discussed. The obtained ormocer shows good mechanical strength, which can be cut and polished in machine without broken.     

海洋钻井液有机物添加剂生物降解性评价

随着海洋石油的勘探开发，钻井液有机添加剂不可避免地进入海洋．因此在海洋勘探开发过程中应选择环保性能好，即生物降解性能好的有机物添加剂。用累计耗氧量法测定了海洋钻井液有机添加剂的生物降解性，研究评价了有机添加剂的生物降解规律和机理，探讨了有机物生物降解性同其化学结构的内在联系，为海洋勘探开发过程中选择环保性能好的有机物添加剂提供理论依据。总结实验结果发现：淀粉类(如DFD-140和FI-E1等)最容易生物降解；其次是纤维素类(如MV-CMC等)和烯类单体聚合物(如PAM和PHP)；而沥青类、两性离子类则难以生物降解，有的甚至对生物降解起抑制作用。