果梅绿原酸超声提取工艺及其抗氧化活性

为探明超声波辅助乙醇提取果梅果绿原酸的最佳工艺及其抗氧化活性,研究了乙醇浓度、料液比、pH、超声时间、超声温度、提取次数对绿原酸提取量的影响,并测定了绿原酸对氧化自由基的吸收能力(ORAC)。结果表明,乙醇浓度60%、料液比(g:mL)为1:7、pH为4、超声时间30 min、超声温度50 ℃,提取3次为果梅果绿原酸提取的最佳工艺,此工艺条件下绿原酸提取量为19.8 mg/10 g鲜重。绿原酸对氧化自由基的ORAC值为258869 mmol/g,芦丁的ORAC值为155981 mmol/g,二者抗氧化能力有显著差异(0.01相似文献   

响应曲面法优化蓝莓渣多酚提取工艺

实验采用乙醇提取蓝莓渣多酚。在单因素实验的基础上,使用DesignExpert7.0软件设计,通过Plackett-Burman实验及响应曲面实验分析确定了乙醇提取蓝莓渣多酚物质的最佳工艺条件为:乙醇浓度60%,液料比20(mL/g),提取温度80℃,pH2,蓝莓渣多酚提取率为97.01%。     

Aerobic biodegradation of diethyl phthalate by Acinetobacter sp. JDC-16 isolated from river sludge

A gram negative bacterium, named JDC-16, which can grow well on the substrate of phthalic acid esters (PAEs) as the sole source of carbon and energy, was isolated from river sludge. Based on the morphology, physiological and biochemical properties and analysis of 16S rRNA gene sequence, it was preliminarily identified belonging to the genus Acinetobacter. The result of substrates utilization range indicates that strain JDC-16 can utilize a variety of phthalates except for diisononyl phthalate (DINP). The degradation tests using diethyl phthalate (DEP) as the model compound show that the optimal pH and temperature for DEP degradation by Acinetobacter sp. JDC-16 is 8.0 and 35 °C, respectively. Meanwhile, degradation kinetics under various initial concentrations of DEP reveals that substrate depletion curves fit well with the modified Gompertz model with high correlation coefficient (R ²>0.99). Furthermore, the substrate induction test indicates that DEP-induction can apparently shorten the lag phase and enhance the degradation rate. This work highlights the potential of this isolate for bioremediation of phthalates-contaminated environments.     

避雨栽培对藤稔葡萄果实品质的影响

葡萄设施栽培是露地自然栽培的特殊形式，主要是利用各种设施创造适合葡萄生长发育的环境条件，以克服自然环境的不足，从而实现栽培目标的人工控制或调节。近年来，由于矮化密植早丰产技术的发展，果品淡季供应的高额利润，设施材料的不断改进以及环境控制技术的提高等因素，使得葡萄设施栽培迅猛发展起来。在我国南方地区，由于高温多雨的气候条件，露地葡萄病害严重，产量低，品质差。避雨栽培作为设施栽培的一种形式，因其设备简单，投资小，见效快，已经成为南方葡萄设施栽培的一种发展趋势。本文以南京地区栽培的藤稔葡萄为试材，主要…     

青梅组分抗食源性致病菌活性分析

为研究青梅中具有抗食源性致病菌活性的部位和成分,将青梅的乙醇提取液用氯仿、乙酸乙酯、正丁醇萃取,对4个萃取组分进行抗菌活性的测定,并对活性最高的组分进行液相色谱-质谱(LC-MS)分析。结果表明:各组分对5种食源性致病菌都有一定的抑菌活性,尤以乙酸乙酯萃取物的抑菌能力最强。对乙酸乙酯萃取物进行LC-MS分析,结果表明,分离效果很好,其主要化学成分类型为咖啡酰莽草酸及其衍生物。提示:咖啡酰莽草酸类化合物具有较好的抗菌活性。