微波辅助提取巨尾桉叶多糖及其抗氧化性研究

以巨尾桉叶为原料,开展了微波辅助水提法提取巨尾桉叶多糖的工艺优化研究,建立了葡萄糖为标准品测定多糖的定量分析方法,考察了巨尾桉叶多糖的抗氧化性。实验结果表明,测定波长为489 nm下的标准曲线方程为:y=0.014 5x+0.000 8;巨尾桉叶多糖提取的优化工艺为:微波功率为480 W,液固比为45∶1 m L/g,提取时间为7 min,多糖提取率为9.17%;巨尾桉叶多糖对DPPH·和过氧化氢的清除率分别为70.05%和84.7%。     

巨尾桉叶中单宁提取及其缓蚀性能研究

采用回流法以水提取巨尾桉叶中单宁,并对其缓蚀性能进行研究。静态失重缓蚀实验表明,在盐酸浓度0.8 mol/L,酸洗温度40℃,酸洗时间4 h条件下,单宁具有一定的缓蚀效果。当0.6 mg/mL单宁、0.4 mg/mL乙酸锌、0.6 mg/mL乌洛托品进行等体积复配时,缓蚀率提到93.05%。     

巨尾桉叶中单宁提取及其缓蚀性能研究

采用回流法以水提取巨尾桉叶中单宁,并对其缓蚀性能进行研究。静态失重缓蚀实验表明,在盐酸浓度0.8 mol/L,酸洗温度40℃,酸洗时间4 h条件下,单宁具有一定的缓蚀效果。当0.6 mg/mL单宁、0.4 mg/mL乙酸锌、0.6 mg/mL乌洛托品进行等体积复配时,缓蚀率提到93.05%。     

巨尾桉单宁的提取分离及其抗菌抗氧化性能

采用超声波辅助法提取了巨尾桉叶中的单宁,大孔树脂吸附法纯化了粗提物,考察了提取物对8种常见菌种的抑制作用和对H2O2、DPPH.和.OH的清除作用。结果表明,巨尾桉单宁的提取得率为4.01%;经树脂分离纯化后单宁质量分数达到53.12%;巨尾桉单宁对除大肠杆菌外的供试菌种均有较强的抑制作用,纯化后的单宁对金黄色葡萄球菌、酵母菌和痢疾杆菌的最低抑菌质量浓度(MIC)均为1.0 g/L,对蜡状芽孢杆菌和沙门氏菌的抑制作用优于阳性对照物;粗提物、纯化物在质量浓度为0.50 g/L时对H2O2有最大清除率,分别为80.00%、89.12%,其IC50分别为0.11、0.12 g/L;抗坏血酸、粗提物和纯化物均在质量浓度为1.50 g/L时对DPPH.有最大清除率,分别为98.43%、88.97%和92.21%。在清除.OH体系中,粗提物、纯化物均在质量浓度为4.00 g/L时有最大清除率,分别为87.52%和94.32%,各试样对.OH的清除能力依次为抗坏血酸>纯化物>粗提物。     

巨尾桉叶中原花色素提取工艺比较及不同溶剂萃取物生物活性的研究

通过正交试验探讨了巨尾桉叶中原花色素的3种提取方法的最佳提取工艺条件,并进行了对比。结果显示,传统溶剂提取法的最优工艺为:60%乙醇、80 ℃、100 min、料液比1:14(g:mL,下同),原花色素得率5.95%;微波辅助提取法的最优工艺为:50%乙醇、微波功率200 W、微波时间4 min、料液比为1:20,得率5.48%;超声波辅助提取法的最优工艺为:60%乙醇、60 ℃、超声波时间25 min、料液比为1:14,得率为6.07%。超声波辅助提取法效果最好,时间短,得率高。实验对超声波提取物的不同溶剂萃取物体外抗氧化性和抗肿瘤活性进行了研究,结果表明,乙酸乙酯萃取物抗氧化作用较强,当质量浓度为1.2 g/L时,对DPPH自由基清除率达到96.33%;乙酸乙酯萃取物质量浓度为2 g/L时,对于人肝癌细胞Bel-7404具有很强的抗肿瘤活性,抑制率为56.37%。     

微波辅助提取山楂红色素及其抗氧化性的研究

对山楂红色素的微波辅助提取条件进行了选择,并简单研究其抗氧化性。实验结果表明,用95%乙醇溶液(pH 2)为浸提剂,用微波处理1 min,然后再常温浸提5 h,浸提效果最佳。此外,山楂红色素对羟自由基具有一定的清除作用,且随着提取浓度下降其清除能力逐渐减弱。     

芦荟多糖的微波辅助提取及其保湿性能研究

通过微波提取技术从芦荟中提取芦荟多糖,采用单因素和正交试验,分别考察了微波辐射功率、时间、料液比、温度等因素对芦荟多糖提取率的影响。结果表明:微波时间为5 min,微波功率600 W,料液比1∶6 g/m L,温度为50℃时,提取工艺最佳,提取率为0.231 7%。通过干燥器控制湿度的方法对芦荟多糖提取物进行吸湿和保湿性能测试,结果表明芦荟多糖提取物是良好的保湿剂。     

向日葵叶中绿原酸微波辅助提取及抗氧化性研究

以向日葵叶子为原料,采用微波辅助乙醇溶剂提取法,在单因素试验的基础上,通过正交试验对工艺条件进行优化,并对向日葵叶中绿原酸提取液进行抗氧化性研究。研究表明,提取最佳工艺条件为:浸泡时间150 s,微波温度60℃,微波功率300 W,乙醇体积分数65%,料液比1∶15。在此条件下,向日葵叶中绿原酸的提取率达到3.802%。各因素对向日葵叶中绿原酸提取率的影响次序为:浸泡时间乙醇体积分数微波温度微波功率料液比。抗氧化性研究表明,向日葵叶中绿原酸提取液对羟基的清除率随质量浓度的增加而增大,清除率最大为80.49%,且效果比Vc的更好。     

微波辅助提取桑葚多糖的工艺研究

采用微波辅助技术提取桑葚中的多糖,考察微波辐射时间,液固比,溶剂pH值,提取次数等因素对多糖的提取得率的影响,结合正交试验进行优化。结果表明：最佳工艺条件为料液比1：25g／mL;微波辐射150s;提取3次。在最佳工艺条件下,多糖得率为11．31％。与热回流和超声提取相比,微波提取方法具有快速、高效、节能、得率高等优点。     

巨尾桉单宁的纯化工艺及其抗氧化抑菌性能

利用NKA-9大孔树脂纯化了巨尾桉树皮和树叶中的单宁,并采用二苯基苦基肼自由基(DPPH·)和羟基自由基(·OH)的清除作用评价了其抗氧化性,采用滤纸片扩散法测定了其对5种常见食源性致病菌的抑菌作用。结果表明,在上样质量浓度0.8 g/L、上样量10 mL、体积分数80%乙醇解吸液用量为3倍柱体积(BV)的动态纯化条件下,树皮单宁纯化物中单宁的质量分数为47.82%;在上样质量浓度0.5g/L、上样量10mL、体积分数80%解吸液用量3BV的动态纯化条件下,树叶单宁纯化物中单宁的质量分数为37.00%。树皮和树叶中单宁纯化物对DPPH·的半抑制浓度(IC50)分别为0.0121和0.0168g/L;当单宁质量浓度为0.6 g/L时,对·OH的清除作用相当于V_C的2.55和2.19倍。树皮和树叶中单宁纯化物对大肠杆菌、金黄色葡萄球菌、痢疾杆菌、沙门氏菌、蜡状芽孢杆菌的抑制作用均强于粗提物,且对痢疾杆菌的抑菌圈直径分别达13.25、12.50 mm。     

微波辅助法提取夹竹桃叶中生物碱的工艺研究

以夹竹桃叶为原料,用微波辅助醇提水沉法提取夹竹桃叶中生物碱。在单因素试验基础上,以正交实验考察了提取过程中的各影响因素,再以回归正交实验优化了提取工艺。各因素对夹竹桃叶中生物碱提取率的影响次序为:料液比>微波温度>微波时间>乙醇体积分数>微波功率。得最佳工艺条件为:乙醇体积分数80%,微波时间90s,微波温度70℃、微波功率300W,料液比1:25(g/mL),浸泡时间4min,在此条件下,夹竹桃叶中生物碱提取率达7.9256%。     

香樟叶中黄酮类化合物提取方法和抗氧化性的研究

通过各种方法提取香樟叶中的黄酮类化合物,比较不同提取方法的提取效率及提取物中黄酮类化合物的含量,从而得到最佳的提取方法。结果表明,体积分数60%乙醇提取法是较好的提取方法。并采用烘箱贮存法测定了该叶片黄酮提取物在猪油中抗氧化活性。结果表明:香樟叶片黄酮提取物具有明显的抗氧化效果,且抗氧化性随添加量的增加而增强。     

Study on the microwave-assisted extraction of polyphenols from tea

This study demonstrated a promising method for quickly extracting tea polyphenol (TP) by microwave-assisted extraction (MAE) technology. Some influential parameters, including MAE temperature, microwave power, concentration of extraction solvent, MAE time and the solid/liquid ratio, were investigated. The optimum condition of MAE was obtained by dual extraction with 60% ethanol (v/v) and the solid/liquid ratio 1:12 g/mL at 80°C for 10 minutes under the microwave power 600W. The yield of TP was 96.5% under the described condition. Compared with traditional methods, including hot reflux extraction (HRE), ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE), the extraction time was saved 8 times than that of HRE, and the yield was increased by 17.5%. The extraction time at comparable levels of production was saved 2 times, and the energy consumption was one fourth that of UAE. The extraction time was saved 5 times than that of SFE, and the yield of TP was increased by 40%. Moreover, compared with MAE of TP studied by others, it decreased the solid/liquid ratio from 1: 20 to 1: 12 g/mL without 90-min pre-leaching time, and the yield of TP was increased by 6%–40%.     

Study on the microwave-assisted extraction of polyphenols from tea

This study demonstrated a promising method for quickly extracting tea polyphenol (TP) by microwave-assisted extraction (MAE) technology. Some influential parameters, including MAE temperature, microwave power, concentration of extraction solvent, MAE time and the solid/liquid ratio, were investigated. The optimum condition of MAE was obtained by dual extraction with 60% ethanol (v/v) and the solid/liquid ratio 1:12 g/mL at 80°C for 10 minutes under the microwave power 600 W. The yield of TP was 96.5% under the described condition. Compared with traditional methods, including hot reflux extraction (HRE), ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE), the extraction time was saved 8 times than that of HRE, and the yield was increased by 17.5%. The extraction time at comparable levels of production was saved 2 times, and the energy consumption was one fourth that of UAE. The extraction time was saved 5 times than that of SFE, and the yield of TP was increased by 40%. Moreover, compared with MAE of TP studied by others, it decreased the solid/liquid ratio from 1 ∶ 20 to 1 ∶ 12 g/mL without 90-min pre-leaching time, and the yield of TP was increased by 6%–40%.