Deformation behaviour of iron-doped alumina

Compressive creep tests in air were carried out on 1 cat.% Fe-doped alumina at a temperature T=1400 °C. Iron doping affected the plastic deformation by different ways in relation with Fe²⁺ cations population. Fe²⁺ cations sped up the deformation rates. FeAl₂O₄ spinel precipitates were identified and they were found (i) to interact with alumina grain boundaries (ii) to limit the grain growth within a range of strain. The Fe²⁺ cations underwent oxidation and this resulted in the dissolution of the some precipitates and in the decrease of deformation rates. It was suggested that deformation sped up this evolution through mass transport and that time was not a dominating parameter.     

Water reuse in a shrimp processing line: Safety considerations using a HACCP approach

The large consumption of water involved in food manufacturing is prompting food processors to optimise the use. Treating and reusing or recycling water within the food plant results in substantial reduction of water use and wastewater production and discharge. If implemented, water reuse should be integrated into existing HACCP programs, and HACCP plans specifically addressed to the actual reuse should be elaborated. This paper evaluates the microbiological safety issues associated with water recycling during the production of shrimps (Pandalus borealis) in brine, and it indicates how the hazards may be effectively controlled using a HACCP approach. Following these procedures, process water recovered from peeling during shrimp processing and treated by means of reverse osmosis could be recycled within the same food unit operation.     

QuEChERS-高效液相色谱串联质谱法测定甜橙中哒螨灵和螺螨酯

[目的]建立了甜橙全果、果肉、果皮、果渣、橙汁和精油等6项基质中哒螨灵和螺螨酯的QuEChERS-高效液相色谱-串联质谱分析检测方法(HPLC-MS/MS)。[方法]甜橙样品经乙腈提取,PSA、GCB、MgSO4净化,高效液相色谱-串联质谱仪配备电喷雾正离子多反应监测(MRM),外标法定量。[结果]甜橙6种基质通过此分析检测方法,哒螨灵和螺螨酯在0.001~1.25 mg/L质量浓度范围线性相关系数不小于0.9965,3个加标水平(0.01、0.5、5 mg/kg)下哒螨灵回收率为81%~93%,RSD为0.5%~6.5%,螺螨酯回收率为81%~99%,RSD为0.5%~7.9%。[结论]该方法简单、方便、灵敏度、准确度高,覆盖甜橙全项样品基质,可适用于大批量样品快速分析。     

氧化鸡肉脂肪制备肉味香精前体物质的研究

研究以鸡肉脂肪为主要原料制备肉味香精的前体物质,通过单因素和正交试验确定氧化反应的最佳反应条件.结果表明氧化鸡肉脂肪的最佳条件是:氧化温度为120℃,氧化时间为3h,VE的添加量为1.0%,不添加水和NaCl.在最优条件下进行氧化试验,得到产物的酸值和过氧化值分别为1.472 mg/g和193.51 mmol/kg,感官评价值为4.905,具有典型特征的鸡肉香气.     

酶促速熟过程中腐乳成分及微观结构的分析

通过研究酶促腐乳在成熟过程中的色度、蛋白质水解程度、微观结构的变化,分析添加酶制剂促熟对腐乳品质及微观结构的影响．利用扫描电子显微镜研究酶促速熟过程中腐乳的微观结构变化,通过电泳分析腐乳的蛋白质水解情况,采用中红外扫描研究酶促腐乳的成分,并与利民红方腐乳（对照样）进行对比．结果表明,酶促速熟腐乳的颜色、微观结构、蛋白水解度以及组成成分均与传统工艺生产的利民红方腐乳（对照样）基本相同,证明腐乳的加酶促进其成熟方法的可行性．     

重组质粒pMG36e-nisI-gfp在乳酸菌中的应用

本研究将带有nisI和咖（绿色荧光蛋白）基因的乳酸菌表达载体pMG36e-nisI-gfp转化至乳酸菌中,观察其在宿主内的稳定性．对重组菌进行了菌体形态、传代培养、质粒验证等研究,考察了该质粒的稳定性．结果显示：重组菌在不含抗生素的培养基中连续传代20代后,质粒丢失率低;菌体大小和形态基本不变;质粒经HindⅢ酶切后大小不变;GFP在第0、5、10、15和20代宿主菌中都可以表达,表达量没有明显差别,在SDS-PAGE中的带型一致;初步的动物实验验证了该质粒作为遗传标记的应用效果．说明该质粒在宿主菌中具有良好的稳定性．     

超声处理对鲢鱼肉肌原纤维蛋白性质的影响

以鲢鱼为原料,研究了超声处理对鲢鱼肉肌原纤维蛋白性质的影响．结果表明：经超声处理后,肌原纤维蛋白的溶解度、起泡性及泡沫稳定性、乳化性及乳化稳定性、热稳定性均随超声时间的延长先提高后下降,且随超声频率的增大而提高．超声处理15min后,与未经超声处理的蛋白相比,80kHz作用下的蛋白溶解度提高了37．59％,起泡性和泡沫稳定性分别提高了59．16％和56．09％,乳化性和乳化稳定性分别提高了51．11％和53．84％,热稳定性提高了32．59％．经超声处理后,鲢鱼肉肌原纤维蛋白的性质可以得到有效的改善．     

链霉菌TD-1菌株抑菌活性物质发酵条件的优化

利用正交设计法及均匀设计法对链霉菌TD-1菌株发酵条件进行了优化,研究不同发酵因子对链霉菌TD-1产抑菌活性物质的影响.结果表明,发酵培养基中影响抑菌活性大小的主要因素为葡萄糖、黄豆粉、硫酸亚铁、磷酸氢二钾及硝酸钾;抑菌活性物质较佳发酵条件为90 mL/250mL三角瓶,接种量的体积分数为0.06,发酵周期8 d,初始pH值为7.15.在此条件下,最终抑菌效率与原发酵液相比发酵液对串珠镰刀菌抑菌活性提高了53.38%.     

Inclusion behavior of oxybutynin with hydroxypropyl-β-cyclodextrin

Inclusion behavior of oxybutynin (OBN) with hydroxypropyl-β-cyclodextrin (HP-β-CD) was investigated by ultraviolet absorption spectrum and fluorescence spectrum. A reliable determination of the complex stoichiometry was provided by the continuous variation technique. Alcohol was added to further investigate the mechanism of the inclusion behavior. Thermodynamic constants ΔG, ΔH and ΔS for inclusion interaction of OBN and HP-β-CD were determined. The results show that host-guest complex with molar ratio of 1:1 is formed, and inclusion stability constant between OBN and HP-β-CD is 54.9 L/mol determined by ultraviolet spectrum and 11.1 L/mol determined by fluorescence spectrum. OBN has weak binding ability with HP-β-CD in aqueous solution (stability constant <10² L/mol) and addition of alcohol leads to a decrease of stability constant, which indicates that the hydrophobic force contributes to the inclusion process. ΔG, ΔH and ΔS are all less than zero, which indicates that the inclusion process is a spontaneous and exothermic process.     

Non-isobaric phenomena in gaseous diffusion through adsorbent porous solids

Pressure gradients were generated during counter-diffusion of adsorbing gases within pelletized activated carbon pellets and modified molecular-sieving carbon pellets even though external isobaric conditions were maintained. Such non-isobaric phenomena were analysed with a zone reaction model which incorporated a flow equation, adsorption equilibrium relationships of gases, and adsorption rates. It was found that pressure gradients are induced within the porous solids by differences in diffusion rates, adsorptivities and adsorption rates of the counter-diffusing gases.