对芳香聚酰胺海水反渗透复合膜元件高压测试系统的修正

以简便实用的公式，介绍了芳香聚酰胺海水反渗透复合膜元件在非标准条件下的膜指标Fa(T,Cf,p,Y)与标准测试条件下的膜指标Fs(25℃，32000mg/L,5500kPa,8%）的相互关系。     

Concentrations of biogenic amines in fish,squid and octopus and their changes during storage

The concentrations of seven biogenic amines (BA) were simultaneously determined in 74 samples of fish, squid and octopus, by the method of HPLC coupled with pre-column derivatisation. The relationship between the formation of BA in aquatic products and the growth of microbial flora during storage was also investigated. Results showed that putrescine, cadaverine, histamine and tyramine were the dominant BA in the studied samples, but the concentrations of histamine and tyramine were mostly less than 50 and 100 mg kg⁻¹, respectively. Freezing can effectively prevent the formation of BA, but the levels of putrescine, cadaverine, histamine and tyramine significantly increased (p < 0.05) during storage at 4 and 25 °C. The growth of mesophilic or psychrophilic bacteria in blue scad and octopus strongly and positively correlated with the formation of amines (such as putrescine, cadaverine, histamine and tyramine) during storage, except for histamine in octopus.     

耐高温复合薄膜用聚氨酯胶粘剂的研究

介绍以芳烃聚酯多醇为主体的双组份 ,干式复合用聚氨酯胶粘剂的合成方法及其性能。讨论了己二酸 苯酐配比及反应温度、时间对合成芳烃聚酯及胶粘剂性能的影响。     

Single‐point determination of intrinsic viscosity of wholly aromatic thermotropic copolyesters in 1,1,1,3,3,3‐hexafluoro‐2‐propanol

A series of wholly aromatic thermotropic copolyesters based on 4‐hydroxybenzoic acid, hydroquinone, and 2,6‐naphthalene dicarboxylic acid were synthesized by direct melt polymerization with or without different added transesterification catalysts. Nine procedures for calculation of the intrinsic viscosities from a single viscosity measurement for polymer solutions, including a proposed one, were applied for the thermotropic copolyesters in 1,1,1,3,3,3‐hexafluoro‐2‐propanol at 30°C. Various forms of the Huggins and Kraemer equations, singly or combined, yielded intrinsic viscosities that were in good agreement with extrapolated values obtained in the usual manner from multipoint viscosity measurements over a wide range of concentrations. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3396–3401, 2001     

Synthesis of N-Substituted （Z）-3-（ （2-Benzyl）-4-Ox opent-2-yl） Pyrrole-2,5-Diones （Maleimides）

A series of N-substituted （Z）-3-（（2-benzyl）-4-oxopent-2-yl）pyrrole-2,5-diones were synthesized and characterized. The compounds were synthesized from dimethyl-2-（（Z）-2-（benzylamino）-4-oxopent-2-en-3-yl） fumarate （9） and dimethyl acetylenedi-carboxylate followed by reaction with some amines in refluxing ethanol. The identification of the compounds were based on spectroscopic analysis such as 1R （infrared）, UV （ultraviolet）, ^1H-NMR （nuclear magnetic resonance） and the microanalysis of the elements （CHN （microanalysis）） data.     

猕猴桃香精的调配

简要论述了猕猴桃香精的香气挥发性成分及其香气类型，同时在此基础上给出了一个猕猴桃香精配方。     

天然香料植物的超临界CO2萃取及应用问题

本文结合我国天然香料植物资源的利用情况及超临界流体技术在天然香料植物提取方面的应用和存在的问题进行讨论。提出为加快我国天然香料资源的利用 ,发展边远地区的经济和香料经济作物的种植 ,应充分发挥联合的优势 ,应用新技术 ,开发新产品 ,提高资源的利用率和经济效益     

Physicochemical Properties,Microbial Profile,and Biogenic Amines Content of Barramundi (Lates calcarifer Bloch) Fillets Wrapped in Selected Packaging Films Under Modified Atmosphere Packaging

The purpose of this study was to investigate the effect of packaging film on physicochemical properties, microbial profile, and biogenic amines content of barramundi (Lates calcarifer Bloch) fillets packed in polyamide, polypropylene, and low-density polyethylene films and kept at 8°C more than 20 days under modified atmosphere packaging. Putrescine and cadaverine were the most abundant amines, whereas the concentration of histamine ranged from less than 0.5 (not detected) to 198.0, 264.3, and 308.5 mg/kg for polyamide, polypropylene, and polyethylene (low-density polyethylene) films, respectively. Among the three, the psychrotrophic bacteria count was initially 4.26 log colony forming units/g and exceeded the acceptable limit of 7 log colony forming units/g on the 16th day of storage for polyamide and on 12th day of storage for polypropylene and polyethylene. However, the total plate count, among the three packaging films, was initially 3.54 log colony forming units/g and exceeded the acceptable limit of 6 log colony forming units/g on the 12th day of storage. The histamine-forming bacteria count was significantly (p < 0.05) lower in barramundi fillets packaged with polyamide compared to polypropylene and polyethylene. The significant difference (p < 0.05) was observed between the concentration of amines in polyamide as compared with polypropylene and polyethylene. Among the three packaging materials, polyamide was found to be the best for prolonging the storage of barramundi fillets.     

Determination of biogenic amines in fresh and processed meat by ion chromatography and integrated pulsed amperometric detection on Au electrode

A selective cation exchange chromatographic method, coupled to integrated pulsed amperometric detection, has been developed to quantify biogenic amines in fresh and processed meat. The method is based on gradient elution of aqueous methanesulfonic acid with post column addition of a strong base to obtain suitable conditions for amperometric detection. A potential wave-form able to keep long time performance of the Au electrode was set up. The analysis time is about 68 min. Amounts of tyramine, putrescine, cadaverine, histamine, agmatine, spermidine and spermine were measured, after extraction with perchloric acid. The method was used to determine analytes in fresh and processed meat. Analyte quantification was made with external calibration method after demonstration that matrix effects were not present. All analytes were identified in real samples except phenethylamine which is eluted in a zone of the chromatogram rich of interfering peaks. Repeatabilities, computed on their amounts in real samples, were better than 9% for all of them. Detection limits were computed according to the Hubaux–Vos method. The obtained values ranged between 0.70 and 2.12 mg/l corresponding to 7–21 mg/kg, low enough to determine all analytes in real matrices.