Comparison of chemical, electrophoretic and in vitro digestion methods for predicting fish meal nutritive quality

Chemical, electrophoretic and in vitro digestion methods were compared with respect to predictions given regarding fish meal (FM) quality. FMs were manufactured by mixing a press-cake, with spray dried stickwater concentrate from the identical raw material, thereby providing samples containing different quantities of water-soluble protein (wsp). A low-temperature-dried FM was employed as a reference. Acquired chemical data for each of the FMs included amino acid analysis and proximal composition (protein, fat, ash, ammonia, titration, salt, moisture). Biological methods in rat (net protein utilization, NPU, biological value, BV, and true digestibility, TD), capillary electrophoresis (sodium dodecyl sulphate-capillary gel electrophoresis, SDS-CGE)) and an in vitro enzymatic assay (trinitrobenzene sulphonic acid-based closed system with rainbow trout enzyme extract) were used for further comparisons with FM wsp content. A high correlation ( R  = 0.97; P  < 0.001) between FM wsp content and titration volume was observed. In contrast to BV and NPU ( R  = 0.98; P  < 0.001), TD ( R  = 0.2; P  = 0.63) did not correlate with FM wsp. The peak area of a 50 kDa signal derived from SDS-CGE showed significant correlation ( R  = 0.98; P  < 0.001) with wsp content. The fish-based in vitro system provided correlations with wsp content with respect to predigestion ( R  = 0.97; P  < 0.0001) and post digestion ( R  = 0.77; P  < 0.03) and for enzymatic liberation of amino groups as post digestion minus predigestion ( R  = 0.97; P  < 0.0001) from the FM examined.     

非扫描式光学SPR生物传感器的数据分析

提出了一种用于求解非扫描式光学SPR共振反射光谱信号的共振像素位点的最小二乘法多项式拟合方法,最大限度地提高信噪比.描述了滑动平均值滤波、多项式数据拟合方法的原理和共振反射光谱最低点的质心算法.采用体积分数为13％,14％,16％,17％,18％,19％的乙醇溶液进行试验验证.结果表明,多项式拟合算法对光功率变化等环境...     

SPR生物传感器快速检测醋酸甲羟孕酮的初步应用研究

动物源性食品中残留的醋酸甲羟孕酮(medroxy progesterone acetate,MPA)对人类健康有潜在的危害。利用SPR生物传感器快速检测MPA,对抗原的固定条件、抗体的浓度及芯片再生条件进行了优化,同时对抗体的稳定性及特异性进行了分析。结果显示,该方法检测的最低限约为1 ng/mL。利用模拟标本进行平行测试表明,其与进口ELISA检测试剂盒结果基本一致。SPR生物传感器检测MPA,单个样品的检测时间小于5 min,非常适合现场的快速检测,具有广泛的应用前景。     

利用表面等离子谐振免疫生物传感器检测动物组织中的兽药残留

表面等离子谐振免疫生物传感器已成为分析生物分子特异性相互作用的有效工具.20世纪90年代已来,有几家实验室进行了应用该技术筛选检测动物组织及体液中兽药残留的研究,结果表明该方法具有快速、准确、灵敏度高和实时检测的特点,有可能作为筛选方法用于大批量样品的兽药残留检测.本文简要介绍了这种生物传感器检测动物组织及体液中兽药残留的原理及检测某些兽药残留的性能.