微波提取无花果叶中的总黄酮及其体外抗氧化活性研究

采用微波法提取无花果叶中的总黄酮,考察乙醇体积分数、液料比、提取功率、提取时间对总黄酮提取率的影响,并进行四因素四水平正交试验,得到总黄酮的最佳提取工艺条件为:乙醇体积分数90%,液料比55∶1(mL/g),提取功率200 W,提取时间3 min,黄酮的含量为20.56 mg/g;该提取物对DPPH自由基去除率达66.67%,羟基自由基去除率达30.49%,证明其具有较好的体外抗氧化能力。     

微波辅助提取葡萄皮渣总黄酮及其抗氧化性研究

研究葡萄皮渣总黄酮的微波辅助提取工艺及体外抗氧化活性。在单因素试验基础上,通过L_9(3~4)正交试验考察微波辅助法各因素对葡萄皮渣总黄酮提取率的影响。优化后工艺为:乙醇浓度60%(体积分数)、料液比1∶25(g/m L)、微波时间120 s、微波功率440 W,提取2次。在此条件下,总黄酮提取率为38.64 mg/g。体外抗氧化试验中,葡萄皮渣总黄酮提取物表现出明显的抗氧化能力,对DPPH自由基和羟基自由基具有较好的清除能力。     

响应面法优化蒲桃叶总黄酮的提取工艺及其抗氧化活性

为研究蒲桃叶总黄酮的提取工艺及其抗氧化活性,以蒲桃叶为原料,采用微波辅助法提取其总黄酮.以单因素试验为基础,选择乙醇体积分数、液料比、微波功率、微波时间为自变量,总黄酮提取率为因变量,对蒲桃叶中总黄酮的提取工艺进行响应面优化.结果表明蒲桃叶总黄酮最优提取工艺为乙醇体积分数59％、液料比53:1(mL/g)、微波功率40...     

蒲桃叶多酚微波辅助提取工艺及抗氧化活性研究

为研究蒲桃叶多酚的微波辅助提取工艺,明确蒲桃叶多酚体外抗氧化活性.在单因素试验基础上通过响应面法优化蒲桃叶多酚的提取工艺,考察乙醇体积分数、液料比、微波功率、微波时间四个因素对蒲桃叶多酚提取率的影响,通过蒲桃叶多酚对DPPH自由基和羟自由基的清除效果来评价其抗氧化活性.结果表明,蒲桃叶多酚最佳提取工艺条件为乙醇体积分数...     

响应面法优化无花果叶总黄酮超声辅助提取工艺

采用超声波辅助提取无花果叶中总黄酮的工艺,并考察了其抗氧化活性。根据单因素试验结果,用响应面法对总黄酮提取工艺进行优化。结果表明,最佳提取工艺条件为：乙醇体积分数70%,液料比30∶1（mL∶g）,超声时间25 min,超声温度70 ℃。此最佳条件下,总黄酮提取率为27.379 mg/g,而模型预测总黄酮提取率为27.384 mg/g,理论预测值与试验结果接近。通过试验得出,该提取物对ABTS自由基、超氧阴离子自由基清除率分别为65.23%、73.21%,证明其具有较好的体外抗氧化能力。     

响应面试验优化诺丽果黄酮微波辅助提取工艺

以诺丽果为原料,通过单因素及响应面试验对诺丽果中黄酮类化合物的微波辅助提取工艺进行优化,结果表明,黄酮类化合物最佳提取条件为乙醇体积分数50%,液料比50∶1（mL∶g）,微波辅助提取时间3 min,微波功率300 W,在该条件下获得的黄酮提取率的平均值为25.98 mg/g。通过试验得出,当提取液质量浓度为8.00 mg/mL时对DPPH自由基、·OH去除率最高,分别为92.8%、82.2%,证明其具有较好的体外抗氧化能力。     

超声-微波协同提取甘草渣中总黄酮工艺优化

为提高甘草的综合利用,该研究以甘草渣为原料,采用响应面法优化超声-微波协同提取甘草渣中总黄酮的提取工艺条件。考察液料比、微波功率、乙醇体积分数和提取时间对甘草渣中总黄酮提取率的影响,根据响应面试验结果,建立总黄酮提取率的回归方程,获得甘草渣中总黄酮的最佳提取工艺条件为：液料比28.4∶1（mL∶g）、微波功率125 W、超声功率300 W、乙醇体积分数79%、提取时间32 min。在此条件下,甘草渣中总黄酮的提取率为2.59%。     

响应面优化超声-微波协同提取石榴叶中总黄酮工艺的研究

为确定石榴叶中总黄酮提取的最佳工艺,在单因素试验的基础上,应用响应面法优化石榴叶中总黄酮的提取条件。结果表明:微波功率、提取时间和料液比对黄酮提取率影响极显著;最佳工艺为:乙醇体积分数71.5%(v/v),微波功率662 W,提取时间262 s,液料质量体积比33.5g/m L,在此条件下提取1次,石榴叶中总黄酮的提取率为89.21%。     

茄子皮中花色苷提取方法的比较及其抗氧化活性研究

以茄子皮为原料,采用3种提取方法(微波提取法、有机溶剂提取法、超声波提取法)提取花色苷,结果表明:微波提取法的花色苷含量最高。在单因素试验基础上,采用响应面法优化工艺参数,得出最佳茄子皮花色苷微波提取工艺为:微波功率480 W,微波时间40 s,液料比50∶1 mL/g,乙醇体积分数80%。在此条件下,花色苷含量为8.81 mg/g。采用清除DPPH自由基和羟自由基方法对茄子皮提取物进行体外抗氧化试验,结果表明茄子皮提取物具有一定的体外抗氧化能力。     

石榴皮总黄酮提取工艺及其体外抗氧化活性研究

建立提取石榴皮总黄酮的工艺条件,并评价其体外抗氧化活性,为有效利用石榴皮资源提供科学依据。采用正交试验方法,以提取物得率为考察指标,对石榴皮总黄酮提取方法的影响因素进行探讨,并对石榴皮总黄酮提取工艺进行优化。分别采用清除DPPH自由基能力及铁离子还原能力对石榴皮总黄酮的抗氧化活性进行测定。石榴皮总黄酮的回流提取最佳工艺为:乙醇体积分数70%、料液比1∶20(g/m L)、提取温度80℃、提取时间2 h,在此条件下,石榴皮总黄酮的提取率达到22.56%。影响石榴皮总黄酮提取效果的主次因素为:乙醇体积分数提取温度料液比提取时间。石榴皮总黄酮对DPPH自由基的最大清除率为80.59%,其IC_(50)值为31.59 mg/L。     

Changes in smoking prevalence in Ukraine in 2001-5

Objectives

To analyse trends in smoking prevalence in Ukraine from three surveys conducted in 2001–5, and to explore correlates of observed changes, in order to estimate the stage of tobacco epidemic in Ukraine.

Design

Repeated national interview surveys in Ukraine in 2001, 2002 and 2005.

Main outcome measure

Prevalence of current smoking among the population aged ⩾15 years.

Results

The age‐standardised prevalence of current smoking in Ukrainian men was 54.8% in 2001 and 66.8% in 2005. Among Ukrainian women, prevalence increased from 11.5% in 2001 to 20.0% in 2005. ORs for yearly increase in prevalence were estimated as 1.164 (95% CI 1.111 to 1.220) for men and 1.187 (1.124 to 1.253) for women, which implies that, on average, 3–4% of men and 1.5–2% of women living in Ukraine join the smoking population each year.

Conclusions

In Ukraine, smoking prevalence is increasing in most population groups. Among men, the medium deprivation group with secondary education has the highest smoking prevalence. Among women, while the most educated, young and those living in larger cities are the leading group for tobacco use, other groups are also increasing their tobacco use. Tobacco promotion efforts appear to have been significantly more effective in Ukraine than smoking control efforts. The decrease in real cigarette prices in Ukraine in 2001–5 could be the main factor explaining the recent growth in smoking prevalence.Ukraine is a large eastern European country with high smoking prevalence. Tobacco products are widely available at very low prices, and the transnational tobacco industry is extremely successful in promoting its products and lobbying for its interests in the legislative field. Advocacy of tobacco control has only recently achieved some success in the legislative field, with the first tobacco control law being adopted in late 2005. Ukraine ratified the Framework Convention on Tobacco Control in 2006, but there is still much cause for concern regarding the enforcement and effectiveness of the adopted legislative measures. Unfortunately, the government is not yet involved in nationwide surveillance of the tobacco problem, and the available data have mostly been gathered with funding from foreign donors. Several attempts have been made to measure the extent of the tobacco epidemic in the countries of the former Soviet Union (FSU).^{1,2,3,4,5,6,7} Most of these studies have shown rather high smoking prevalence among men (50–70%) and comparatively low prevalence among women (5–20%). Most countries in the FSU have similar smoking rates, while certain trends are shown to be related to the differences in how the transnational tobacco industry succeeds in every national tobacco market.⁶ Unfortunately, few studies have been published showing trends in smoking prevalence in the FSU.⁷ In Ukraine, two studies^3,4 provided point estimates of smoking prevalence.The aim of this study was to analyse trends in smoking prevalence in Ukraine, on the basis of three surveys conducted in 2001–5, and to explore correlates of observed changes in order to estimate the stage of the tobacco epidemic in Ukraine.     

2010年河南省部分食品中重金属污染状况分析

了解河南省部分食品中重金属污染的现状。方法 在河南省18个省辖市采集8大类3 657份食品样品,按照国家标准检测食品中铅、镉和汞的含量,检测结果按照GB 2762—2012《食品安全国家标准食品中污染物限量》进行评价。结果 河南省部分食品中铅含量的平均值为0.34 mg/kg,总体超标率为8.8%(320/3 656),其中粮食、肉类和蔬菜中超标率较高,分别为17.2%(95/552)、14.5%(85/587)和10.7%(57/534);部分食品中镉含量的平均值为0.054 mg/kg,总体超标率为3.9%(143/3 657),其中食用菌和蛋类中超标率较高,分别为9.6%(49/508)和8.1%(42/518);部分食品中汞含量的平均值为0.077 mg/kg,总体超标率为8.3%(303/3 657),其中蔬菜和粮食中超标率较高,分别为25.3%(135/534)和12.3%(68/551)。结论 河南省部分食品中铅、汞污染情况较为严重,其中粮食、蔬菜和肉类食品中污染情况尤为突出,需要加强监管。     

Moulds and mycotoxins in sorghum stored in traditional containers in India

Various traditional containers have been used in India for storage of sorghum grains. Sorghum is susceptible to fungal infestation and toxin elaboration. The present study relates to the mould and mycotoxin contamination (aflatoxin B₁ and T-2 toxin) in stored sorghum in different storage containers viz. “Kotlu” (Storage rooms), earthenware pots, gunny bags and reed baskets. Aspergillus sp. and Fusarium sp. were the prominent genera and the “Kotlu” form of storage was most susceptible to fungal attack. Storage treatment had little effect on fungal contamination, but despite the fungal infestation, the mycotoxin contamination was found to be very low.     

中国固态发酵白酒中功能细菌研究进展

细菌是白酒酿造3大类微生物之一,其在白酒生产中有着重要的作用,如:芽孢杆菌、乳酸菌、放线菌和梭菌等,它们能产生酯类、有机酸、吡嗪、萜烯等微量成分,从而影响白酒的风味与品质。基于细菌在白酒中的重要功能以及微生物分离培养技术和分析检测技术的进步,近年来相关研究越来越深入。该文综述了近年来白酒功能细菌的研究进展,介绍了酿酒各个环节中主要功能细菌及其在白酒中的作用,旨在为白酒功能细菌的研究提供参考。     

2010年山西省食品中食源性致病菌监测分析

目的 了解山西省食源性致病菌的污染现状.方法 按照2010年度《全国食源性致病菌监测工作手册》进行.结果 1 576份样品中共检出阳性菌株149株,检出率为9.45％,其中单核细胞增生李斯特氏菌、副溶血性弧菌污染比较严重,总检出率为9.50％和8.22％,金黄色葡萄球菌、阪崎肠杆菌和沙门氏菌的总检出率分别为3.02％、1.11％和0.87％.不同类别食品中致病菌的检出率差异较大,生肉中致病菌的检出率高居榜首为49.33％,主要污染菌为沙门氏菌、单核细胞增生李斯特氏菌;沙拉中致病菌的检出率为17.39％,主要污染菌为单核细胞增生李斯特氏菌、金黄色葡萄球菌;生食水产品中致病菌的检出率为16.94％,主要污染菌为单核细胞增生李斯特氏菌、副溶血性孤菌;熟肉制品中致病菌的检出率为9.84％,主要污染菌为单核细胞增生李斯特氏菌、金黄色葡萄球菌、沙门氏菌;中式凉拌菜中致病菌的检出率为8.89％,主要污染菌为金黄色葡萄球菌;鲜榨果汁中致病菌的检出率为6.67％,主要污染菌为金黄色葡萄球菌;鲜冻水产品中致病菌的检出率为5.00％,主要污染菌为副溶血性弧菌;婴幼儿配方粉/米粉/谷粉/豆奶粉中阪崎杆菌的检出率为1.11％.结论 山西省多种食品均存在食源性致病菌不同程度的污染,应加大对散装食品、即食食品和生食水产品的监管.