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1.
《Food Control》2006,17(2):108-113
The concept of food safety has lately acquired a new approach due to globalization and free trade in food. Introducing a HACCP system in the production and trade in food has become a necessity. The term “food trade” indicates all the postproduction procedures, from storage, transport and distribution to retail, including export and import. The aim of our 2002 survey was to analyse the situation of cold chain maintaining in food trade in Ljubljana, the capital of Slovenia. The research was based upon two hypotheses: in the first one we supposed that a cold chain is interrupted in retail and in the second one we supposed that the handling of food in retail varies. Seventeen stores were divided in three groups, according to sales area of the store: large ones, medium ones and small ones. Temperature conditions in cooling appliances for storage of 1688 perishable food products were measured. Products were inspected by two criteria, by the “best before” date and by the storage temperature. The results confirmed both of the hypotheses. The storage conditions were properly labelled on the packages of the products inspected. In most of the cases the temperatures measured differed from the required ones, even for up to 10 °C. The biggest differences were detected between temperatures indicated on cooling appliances and temperatures measured by our calibrated thermometers. Conditions during food storage and in retail stores were not documented and there was no system to control the cold chain. Our findings have shown that retailers are not familiar with the importance of maintaining a cold chain. The result of that can be a shorter durability of highly perishable foodstuffs and their safety for consumers is questionable. 相似文献
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应用静态吸附、动态吸附、程序升温脱附和程序升温还原等实验方法,考察了噻吩在Ni基非晶态合金上的吸附和脱附行为。常温下,噻吩分子首先吸附在清洁的Ni表面,并立刻被活化,发生氢解反应,C-S键断裂,释放出烃类部分,S留在Ni原子上。噻吩可以在Ni基非晶态合金表面发生强度不同的化学吸附。弱化学吸附的噻吩可以脱附;强化学吸附的噻吩不会脱附,而在高温下发生氢解反应。 相似文献
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《International Dairy Journal》2006,16(3):268-273
Buffalo milk proteins (casein, co-precipitate or whey protein concentrate) were phosphorylated with phosphorus oxychloride (POCl3) at three different pH values (5.0, 7.0 and 9.0). The solubilities of phosphorylated milk proteins were examined over the pH range 3.0–9.0 in water and ionic (0.1 m NaCl or 10–70 mm Ca2+) systems. The solubilities of buffalo milk proteins decreased at pH 3.0, while there was an increase in the solubilities of casein and co-precipitate near their isoelectric points upon phosphorylation. Solubilities of these phosphorylated milk proteins were pH dependent in 0.1 m NaCl but there was a decrease in their solubilities with increase in calcium ion concentration. This alteration could be due to the shifting of isoionic points of phosphorylated buffalo milk proteins towards acidic pH. 相似文献
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A new method of studying the corrosion inhibition mechanism of rare earth metal(REM) on LC4 Al alloy with the spilt cell technique was studied. The principle and experimental method of the spilt cell technique were analyzed. By measuring the change of net-electric current between the two electrodes caused by the change of the amount of oxygen in the solution and the addition of CeCl3, the influence of corrosive performance of CeCl3 on LC4 super-power aluminum alloy in the 0.1 mol·L−1 NaCl solution was investigated. Meanwhile, the conditional changes of pH values, CeCl3 solution, additire and time of performance were also studied. Finally, the features of electrode surface were revealed by using SEM and X-ray energy-dispersive spectrometry (EDS). By combining these with other electric chemical techniques, such as potential-time curve, polarization curve et al. 相似文献
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主要研究了Cr对低碳Si-Mn系TRIP钢组织与力学性能的影响。首先利用Formastor-F型膨胀仪测定了含Cr和不含Cr两种低碳钢的连续冷却转变(CCT)曲线,分析指出了Cr对连续退火工艺的潜在影响;然后采用Gleeble-3800热/力模拟试验机对两种钢的薄板试样进行了连续退火模拟实验,并通过拉伸试验测定了力学性能;最后采用金相、扫描电镜、X-射线衍射分析等技术考察分析了两种钢的显微组织。结果表明:含Cr的TRIP钢的组织比较细小,铁素体晶粒近似等轴分布;两种TRIP钢的残余奥氏体含量相近,但含Cr钢的残余奥氏体中的含碳量较高。分析认为这是由于含Cr钢在热轧阶段较易生成细小的组织,而在热处理阶段则抑制贝氏体的生成,最终获得稳定的残余奥氏体。 相似文献
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MIP-CGP工艺专用催化剂CGP-1的开发与应用 总被引:11,自引:3,他引:8
阐述了生产汽油组分满足欧Ⅲ排放标准并多产丙烯的催化裂化工艺(简称MIP-CGP)专用催化剂(简称CGP-1)的研究开发与工业应用结果。CGP-1催化剂的基质具有良好的容炭性能,使活性组元受到良好保护,其优势作用在第二反应区得以充分发挥,具有更高的氢转移活性和强的汽油小分子烯烃裂化活性。中国石化九江分公司和镇海炼化公司的MIP-CGP工业试验标定结果表明,与常规FCC相比,采用CGP-1催化剂的MIP-CGP技术在生产烯烃体积分数小于18%的汽油组分的同时,丙烯产率达到8%以上。此外,汽油诱导期大幅提高,抗爆指数增加;总液体收率有所提高,干气产率下降,焦炭选择性良好。 相似文献