超声辅助同时提取条斑紫菜多糖及藻胆蛋白工艺的优化

以条斑紫菜为原料,通过单因素和正交试验,确定了超声辅助同时提取条斑紫菜多糖和藻胆蛋白的最佳工艺条件.结果表明,超声辅助同时提取条斑紫菜多糖和藻胆蛋白的最佳工艺条件为:超声60min,功率880W,水浴30℃,4h,料液比1:50.利用本法优化后的工艺同时提取条斑紫菜多糖和藻胆蛋白,紫菜多糖提取得率为 34.03%,藻胆蛋白提取得率为1.2%,藻红蛋白纯度为0.356.     

响应面法优化复合酶法提取紫菜藻红蛋白工艺

研究复合酶法提取紫菜藻红蛋白的最优工艺,筛选了复合酶的配比,并选取酶解温度、提取时间、加酶量和pH值为自变量,采用响应面法研究各因素及其交互作用对紫菜藻红蛋白得率和纯度的影响。结果表明,紫菜藻红蛋白复合酶法提取的最优酶配比为纤维素酶和果胶酶质量比7∶3,通过响应面优化,确定藻红蛋白最优提取工艺为：pH 6.8、酶解温度39 ℃、提取时间7.2 h、在5 g样品中加酶0.04 g。在此条件下藻红蛋白得率为2.257%,纯度达到1.656。经过验证,所得工艺参数准确,可用于复合酶法生产紫菜藻红蛋白。     

坛紫菜R-藻红蛋白的稳定性研究

为了揭示坛紫菜R-藻红蛋白（R-PR）的环境稳定性变化规律,分别研究了不同光照强度、温度、pH和金属离子条件下坛紫菜R-藻红蛋白光谱特性的影响。研究结果表明：坛紫菜R-藻红蛋白在40℃以下、弱光（2000lux以内）及pH5.0～8.0条件下相对稳定,光谱特性基本无变化;其中4℃、pH7.0的避光条件下R-PE尤为稳定;高温、紫外线、酸碱环境均影响坛紫菜R-PE稳定性,导致在565nm和498nm处特征吸收峰发生显著减弱并逐渐消失。坛紫菜R-藻红蛋白的两种藻胆色素的热稳定性关系为：藻尿胆素〉藻红胆素。此外,Fe2＋、Fe3＋、Cu2＋对坛紫菜R-PE的稳定性的破坏作用显著,而Ca2＋、Mg2＋、Zn2＋、Mn2＋对其稳定性影响较小。     

坛紫菜R-藻红蛋白的提取技术研究

以坛紫菜为原料,采用反复冻融法、溶胀法和超声波法提取藻红蛋白,并将经该3种提取方法所得藻红蛋白的含量和纯度进行比对。结果表明:反复冻融法以冻融3h、反复冻融6次的藻红蛋白纯度最高,但所需时间周期较长;超声波破碎法以超声波功率300W破碎10min提取的藻红蛋白含量最多;而溶胀法以溶胀4h效果最好,所得藻红蛋白的纯度及含量与所需时间介于前两者之间。因此,坛紫菜R-藻红蛋白的提取可结合产品质量指标要求确定最佳工艺技术参数。     

不同破壁方法对条斑紫菜藻红蛋白提取效果的影响

以条斑紫菜为原料，研究反复冻融法、溶胀法、低盐浓度法和超声波法等破壁方法对条斑紫菜藻红蛋白提取效果的影响，、试验结果表明，采用反复冻融法、溶胀法、低盐浓度法破壁得到的藻红蛋白纯度较高，但所需时间太长，超声波法得到藻红蛋白的纯度虽低于其他3种方法，但提取时间很短，处理量大，适合于工业化生产。     

紫菜中藻胆蛋白的提取及纯化

紫菜经800W功率超声波作用800s，用30倍体积的水浸提得到藻胆蛋白的粗提物，再用饱和度为45％的硫酸铵盐析沉淀及透析后，经羟基磷灰石（HA）层析柱，用不同浓度的磷酸缓冲液梯度洗脱，可分离纯化出紫菜藻胆蛋白（含藻红蛋白和藻蓝蛋白），两种活性组分的纯度（Amaxnm／A280nm）达到4．32。藻红蛋白的最大吸收峰在558nm，藻蓝蛋白的最大吸收峰在616nm。     

条斑紫菜藻红蛋白提取工艺的研究

比较了不同提取方法：水溶法、冻融法、组织研磨法、机械搅拌法、超声波辅助法对条斑紫菜藻红蛋白提取效果的影响。首次将超微粉碎与超声波辅助提取法结合提取藻红蛋白,以条斑紫菜中藻红蛋白的得率和纯度为指标,并优化得到最佳的工艺条件：超声波功率为500W,时间为5min,料液比为1∶50,提取3次,操作参数超声时间为3s,间隙为3s。在此条件下藻红蛋白得率为45.73mg/g,纯度为0.368,提取率为90.2%,该方法大大提高了得率并缩短操作时间,同时荧光特性分析验证此方法获得的藻红蛋白具有较高的活性。     

基于藻红蛋白提取的条斑紫菜脉冲超声破壁方法研究

以条斑紫菜为原料,研究反复冻融法、溶胀法和脉冲超声法等破壁方法对条斑紫菜藻红蛋白提取效果的影响。实验结果表明,采用反复冻融法得到的藻红蛋白提取得率较低。溶胀法破壁得到的藻红蛋白提取得率和纯度均较高,但所需时间太长。脉冲超声法破壁的最佳工艺参数为:对应一个脉冲的超声发出时间2s和间隙时间3s、超声处理时间60min、超声功率800W、料液温度20℃、料液比30mg/ml,对应的藻红蛋白提取得率为3.249%,纯度(OD561/OD280)为0.365,脉冲超声法所需时间短,处理量大,适合于工业化生产。     

双水相萃取法提取条斑紫菜R-藻红蛋白工艺

以条斑紫菜为原料,采用双水相萃取法对R-藻红蛋白进行提取,讨论不同工艺条件聚合物分子大小及质量分数、成相盐质量分数、离子强度对藻红蛋白的提取效果,通过正交试验确定藻红蛋白的最佳提取条件。结果表明当6%聚乙二醇4000、13%硫酸钠、1.5%氯化钠时,蛋白纯度可由粗液的0.187上升至0.727,是传统硫酸铵盐析法的2.25倍,说明双水相萃取法比硫酸铵盐析法更适合提取R-藻红蛋白。     

紫菜活性成分提取技术及其功能特性研究进展

紫菜是我国一种具有重要经济和研究价值的海藻,营养组成上主要含有多糖、藻胆蛋白等营养成分及多酚等活性物质,因此具有良好的抗氧化、抗肿瘤、抗心血管疾病和免疫调节等功效。本文总结了紫菜中营养素多糖、蛋白、多酚等的常见提取方法及体外和体内模型下抗氧化、抗肿瘤、调节免疫等生物活性功能的最新研究进展,以期为紫菜进一步高价值开发利用提供参考和借鉴。     

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.