正交试验优化超声波提取独活有效成分的工艺研究

[目的]优选超声波提取独活有效成分的工艺条件。[方法]采用紫外分光光度法分析总香豆素含量,以独活中总香豆素为评价指标,通过正交试验优选影响提取的3个主要因素(溶剂倍量、提取时间以及乙醇浓度)的最佳条件。[结果]乙醇浓度对总香豆素提取率的影响最为明显,其次是溶剂倍量,提取时间对总香豆素提取率无明显影响。正交试验优选的超声波提取独活总香豆素工艺条件为:料液比1∶10(W/V,g/ml,下同)、提取时间20 min、乙醇浓度60%;在此条件下,独活中总香豆素的提取率为14.095 2 mg/g。[结论]超声波提取独活总香豆素时间短,溶剂用量少,提取效率高。     

Appraisal of fish behaviour based on time series of fish positions issued by a 3D array of ultrasound transducers

We present a novel low-cost analysis platform and method for monitoring the behaviour of a fish population (starry sturgeons – Acipenser stellatus) – in an experimental tank using a 3-dimensional array of ultrasound transducers. The platform provides time series of fish positions, allowing for assessment of the dynamics of geometric centre (centroid) of fish population. We demonstrate that centroid evolution represents a sensitive indicator of fish behaviour under conditions varied from normal towards non-physiological limits, e.g. pH, dissolved oxygen concentration, feeding and light.Emphasis has been given to reversible effects i.e. after normalisation of water parameters undergoing “gentle” variations, the fish behaviour returns to the normal/physiological pattern.Fish behaviour was previously assessed by several techniques (e.g. electrical impedance, video monitoring, hydro-acoustics, etc.).To our knowledge, this is the first study that uses ultrasounds to continuously monitor the three-dimensional position of fish, having also the advantage of being independent on water turbidity or light level.We stress on the capabilities of the platform and related method to assess the occurrence of abnormal fish behaviour, revealed by the change over a predefined threshold exhibited by the dynamics of the fish population exposed to stimuli, and to automatically issue a warning alert (in case of e.g. non-optimum water quality), thus making it suitable for remote, cost effective monitoring of fish behaviour supporting an optimised aquaculturing.     

超声波辅助提取竹叶茶多酚工艺研究

以竹叶为原料，采用超声波辅助提取茶多酚，通过单因素实验和正交试验优化提取条件。结果表明，从竹叶中提取茶多酚的最佳条件为：乙醇浓度60％、料液比1：10、温度65℃、提取时间30min、超声波功率320W，此条件下茶多酚得率为1．78％。     

诃子总多酚恒温超声辅助提取与过程动力学研究

采用三频恒温数控超声辅助提取技术优化了诃子总多酚提取工艺;通过比较试验和扫描电镜分析了该技术高效提取的原因;从Fick第一定律出发建立了诃子总多酚扩散动力学方程,并进行了验证。结果表明,恒温超声提取诃子总多酚最佳工艺条件为:乙醇体积分数60%、超声频率80 k Hz、超声功率180 W、提取温度70℃;该工艺提取效率显著高于水浴振荡提取工艺(P0.001);扫描电镜观察发现,恒温超声提取技术对原料粉末微观结构破坏更严重。结合Fick第一定律及超声提取动力学推导了恒温超声辅助提取诃子总多酚动力学方程;验证试验表明,在相应的范围内,提取时间对数和提取功率对数均与诃子总多酚浓度对数呈正比关系。结果表明:恒温超声辅助技术可用于诃子总多酚高效提取。     

不同处理工艺对黑木耳多糖抑菌活性影响研究

为探讨粉碎工艺与提取工艺（水提及超声提取）处理对黑木耳多糖抑菌活性的影响,以抑菌圈为指标,采用不同的粉碎物料与提取工艺,研究原料粒度与提取工艺对黑木耳多糖抑菌效果的影响。结果表明,原料粒度与提取工艺对黑木耳多糖的抑菌效果均有较大影响,水提时,150目原料粒度提取的多糖对大肠杆菌（Ecoli）和金黄色葡萄球菌饵础re班）的抑菌效果最好,超声处理时,多糖的抑菌效果随着原料粒度减少逐渐下降,且超声处理时多糖的抑菌效果不如水提。     

大豆蛋白超声磷酸化加工工艺的Box-Behnken模型优化

采用超声波处理技术协同大豆蛋白磷酸化加工以提高大豆蛋白的乳化性质,利用Box-Behnken模型对加工工艺过程进行优化,所得模型拟合度高,可用于实际分析和预测.利用响应面分析法探讨了三聚磷酸钠(STP)质量分数、超声波功率、超声波处理时间3因素对改性产物乳化性质的影响,优化的制备工艺条件为:STP质量分数9.65％、超声波功率490W、超声波处理时间34 min,在此条件下产物乳化活性为70.8,乳化稳定性为30.2 min,分别是空白样品的2.18倍和1.57倍.     

废次烟草中茄尼醇提取条件的研究

[目的]寻找提取废次烟草中茄尼醇的适宜条件。[方法]以无水乙醇为提取溶剂,分别用超声法和微波法对废次烟草进行提取,研究微波功率、固液比和烟末粒度3因素对微波提取的影响。[结果]结果表明,用无水乙醇作溶剂,微波提取茄尼醇的提取效果明显优于超声提取,且缩短了提取时间;微波提取废次烟草中茄尼醇的适宜条件为:微波功率180W、处理时间3 min、烟末粒度100目,固液(烟末无水乙醇)比11∶00(g/ml)。[结论]该法可用于废次烟草中茄尼醇的提取。     

Evaluation of ultrasonography for measuring solar soft tissue thickness as a predictor of sole ulcer formation in Holstein–Friesian dairy cows

The aim of this research was to investigate the correlation between the thickness of solar soft tissue (SST; i.e. the corium and subcutaneous tissue) in early lactation and sole ulcer formation in late lactation. Fifty Holstein–Friesian cows were examined three times: (1) 30 days after calving (locomotion scoring, trimming, claw examination, measurement of SST); (2) 70 days after calving (locomotion scoring); and (3) 180 days after calving (locomotion scoring, trimming, claw examination).SST thickness was measured using an 8 MHz linear probe, at two points (SST1 below the apex of the pedal bone, and SST2 below the flexor tubercle). Mean values for SST1 and SST2 were 3.26 ± 0.43 mm and 4.35 ± 0.46 mm, respectively; the two measures were positively correlated (r = 0.95, P < 0.001). At 180 days after calving, a sole ulcer was diagnosed in 12/50 cows (24%). Cows with a thinner SST had a higher risk of developing sole ulcers than those with a thicker SST. The optimal cut-off values of SST1 and SST2 in predicting cows with sole ulcers (as calculated by ROC analysis) was ?3 mm for SST1 and ?3.9 mm for SST2. The relative risk of a sole ulcer developing, based on those cut-off values was 4.25 (95 CI, 1.77–24.88) for SST1 ? 3 mm and 3.63 (95 CI, 1.18–10.8) for SST2 ? 3.9 mm.