Fusarium-inoculated wheat: deoxynivalenol contents and baking quality in relation to infection time

Cereals contaminated by Fusarium spp. and their mycotoxins, e.g. deoxynivalenol (DON), are not only a risk to human and animal health but also show reduced technological properties. This study examines the influence of high Fusarium infection levels of wheat on its baking quality in relation to infection time. Nearly uninfected wheat, wheat inoculated with a spore-mixture of different Fusarium spp. at the time of flowering, and wheat inoculated with spores of Fusarium graminearum at different growth stages were investigated. Extension and baking tests, HPLC analyses of gluten proteins, and DON determination were performed as well as X-ray absorption spectroscopy to analyse the sulfur speciation of gluten proteins on a molecular level. Our results indicate that high Fusarium infection levels accompanied with high DON contents did not necessarily deteriorate baking quality. This finding was independent of infection time.     

LC-MS/MS法测定保健食品中左卡尼汀的含量

目的 建立保健品中左卡尼汀的LC-MS/MS的测定方法。方法 待测样品经超声提取、稀释后, 分别采用CAPCELL PAK CR色谱柱和PC HILIC色谱柱进行分离, 最后用LC-MS/MS进行检测。 结果 使用CAPCELL PAK CR法检测左卡尼汀能够得到更高的灵敏度, 线性范围为0~200 ng/mL, 相关系数为r=0.9995。结论 该方法灵敏度高、准确、重现性好, 可以用于一些保健食品中左卡尼汀的含量检测。     

Dihydrocaffeic acid,a major microbial metabolite of chlorogenic acids,shows similar protective effect than a yerba mate phenolic extract against oxidative stress in HepG2 cells

The hepatoprotective effect of a yerba mate phenolic extract (YMPE), rich in chlorogenic acids, and its main circulating metabolites dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids were assessed in human hepatoma HepG2 cells subjected to oxidative damage induced by tert-butylhydroperoxide (t-BOOH). Direct treatment of HepG2 cells with realistic concentrations of YMPE (1, 10 and 50 μg/mL), DHCA or DHFA (0.2, 1, 10 μM) for 20 h was not cytotoxic and significantly decreased ROS generation. Pre-treatment with YMPE and DHCA prevented the cytotoxicity and macromolecular damage induced by t-BOOH. Moreover, decreased levels of reduced glutathione (GSH), and increased ROS levels and antioxidant enzyme activity induced by t-BOOH were dose-dependently recovered. DHFA only showed a slight protection against cell cytotoxicity, lipid oxidation and GSH depletion. In conclusion, YMPE and one of its major microbial metabolites, DHCA, confer significant protection against oxidative damage, adding evidences to the beneficial health effects associated with mate intake.     

基于柱切换技术的高压液相色谱法检测奶粉中的维生素D

目的 建立奶粉中维生素D的柱切换式高压液相色谱分析方法。方法 奶粉样品经过皂化处理、石油醚提取、脱水浓缩后, 用柱切换式高压液相色谱仪进行检测。结果 维生素D3在0.2~1.0 ?g/mL范围内线性关系良好, 回归方程Y=1.74181e?006X?0.00662911, 相关系数r=0.9956, 检出限为0.01 ?g/mL, 定量限为0.2 mg/kg, RSD为2.12%, 平均回收率为 96.8%。结论 该方法简单、快速、准确, 为复杂基质食品中低含量物质的检测提供一定参考。