Effects of breed and age at slaughter on degradation of muscle lipids during processing of dry‐cured hams

Hams from Landrace, Duroc and Hampshire pigs slaughtered at ages 6, 7.5 and 9 months were processed to generate Norwegian Parma‐style hams. Lipid contents and the compositions of fatty acid classes (ΣSFA, ΣMUFA, ΣPUFA) within neutral lipids, phospholipids and free fatty acids were determined. Small differences in lipid degradation and composition of the classes were revealed. However, significant sensory differences related to lipids were observed. Breed was more important than age. Dry‐cured Hampshire hams gave a more intense mature odour that may be associated with higher overall lipid degradation. Unexpectedly, these hams also demonstrated high juiciness and tenderness, which could be related to the melting characteristics of the fat. Dry‐cured Duroc hams showed a higher susceptibility towards rancidity, presumably associated with preferential oxidation of n‐6 fatty acids relative to C18:1 n‐9. Dry‐cured Landrace hams showed the lowest juiciness and tenderness, likely due to their lower fat content (marbling).     

干腌火腿的质量缺陷及防止措施

由于猪腿原材料或者加工技术的问题,而造成干腌火腿产品质量的多种缺陷。综述了干腌火腿中常见的各种质量缺陷以及防止这些质量缺陷的措施。     

腐殖酸对烤烟根系生长和生理活性的影响

对腐殖酸和基肥混施进行了烤烟盆栽试验。结果表明 ,腐殖酸能有效刺激根系的生理活性 ,提高根系抗坏血酸氧化酶、多酚氧化酶等呼吸酶的活性 ,增强根系的活力 ,并能有效促进烤烟根系生长 ,根干重、体积和长度均有提高。     

Accumulation of thiobarbituric acid‐reactive substances in cured pork sausages treated with propolis extracts

Propolis collected by bees has many components that possess antifungal, anticancer and antioxidant properties. Cured ground pork meat was treated separately with 0.4% w/w ethanol‐extracted propolis (EEP 0.4%), 0.6% w/w water‐extracted propolis (WEP 0.6%), 0.8% w/w dried residue of ethanol‐extracted propolis (DREEP 0.8%) and 0.1% w/w potassium sorbate (PS 0.1%) and made into sausages. Thiobarbituric acid‐reactive substances (TBARS) were measured in the sausages to assess the effects of storage at 5, 10 and 20 °C after 0, 2 and 4 weeks. After 4 weeks of storage at 5 °C the sausages treated with EEP 0.4%, DREEP 0.8%, WEP 0.6% and PS 0.1% yielded TBARS values which were 50, 59, 35 and 91% respectively of the control value. There was an increase of 0.33 mg MDA kg^?1, the lowest of all treatments, in TBARS for the 0.4% w/w EEP‐treated sausages. The curing process will control microbiological spoilage, as will potassium sorbate. © 2002 Society of Chemical Industry     

Phenol novolac/poly(4- hydroxyphenylmaleimide) blend hardeners for DGEBA-type epoxy resin

Phenol novolac/poly (4-hydroxyphenylmaleimide) (PHPMI) blends were used as an epoxy resin hardener. The curing behavior of the above system and the thermal and mechanical properties of the cured epoxy resin were studied. It was not necessary to use a curing accelerator for this system, because PHPMI caused acceleration of the curing reaction. The curing mechanism of this system was investigated by using model compounds. Test pieces from the neat resins and the glass fiber reinforced resins were evaluated in terms of thermal and mechanical properties, respectively. It was found that heat resistance and mechanical properties were improved by increasing the amount of PHPMI in the hardener.     

室温固化双组分水性木器涂料

一种新颖的室温固化双组分水性木器涂料与相应的单组分涂料相比,其显著特点涂膜有极好的附着力、更高的硬度、优异的耐水、耐烫、耐溶剂和抗粘连及耐污渍性等。其配漆后的适用期室温下可达30d以上,涂料的综合性能可与溶剂型漆相媲美。     

CO2水溶性树脂砂的应用研究

介绍了ＣＯ２硬化水溶性聚丙烯酸钠树脂在几种原砂上的应用及其工艺性能，指出该树脂值得大力推广     

Pro/engineer在产品曲面造型设计中的实现与评估

以产品曲面设计评估技术要求为依据,从技术应用角度论述pro/engineer软件在产品曲面设计中的构建方法和检测手段。从而证明pro/engineer在产品曲面设计中的应用可缩短产品的设计过程。     

微波固化环氧树脂(E44/DDM)的热性能及膨胀性能

利用微波辐照固化环氧E44／二苯甲烷二胺(DDM)体系，考察了固化温度、固化时间以及微波功率之间的关系，分析了固化过程。利用FT-IR、DSC、热膨胀仪分别表征了体系的固化度、玻璃化转变温度(Tg)、热分解温度以及热膨胀系数(α)。结果表明，与热固化过程相比，微波能显著提高E44／DDM的固化速度，缩短凝胶化时间。且微波固化物具有较高的热分解温度和较低的线膨胀系数α。     

共混型聚丙烯/超细粉末丁苯橡胶全硫化热塑性弹性体的制备及其结构与性能

以全硫化超细粉末丁苯橡胶(PSBR)与聚丙烯(PP)为原料,采用双螺杆挤出机共混方法制备PP/PSBR全硫化热塑性弹性体。通过透射电镜观测,发现PP/PSBR全硫化热塑性弹性体具有和动态硫化方法制备的热塑性弹性体相似的微观形态,PSBR粒子作为分散相分散在连续相PP中;所制备的热塑性弹性体的力学性能与PP的相对分子质量、共聚与否、PSBR含量及其交联度有关;通过流变行为研究,发现此类全硫化热塑性弹性体为假塑性流体,且橡胶的含量对热塑性弹性体的黏度影响很小;采用差示扫描量热法对PP/PSBR全硫化热塑性弹性体中连续相PP的结晶行为进行了研究,发现连续相PP的结晶温度提高,表明PSBR对PP有异相成核作用。