NH5110核磁共振含油量测定仪在油菜籽含油量测定中的应用

利用核磁共振技术测定油料种子的含油率,是国际上六十年代初开始采用的一项新技术,在国外已广泛应用于许多领域,但在我国还刚刚开始。由于该方法与现在使用的索氏抽提法(或改良直滴式抽提法)相比,具有快速、安全无毒、操作方便、不破坏油料种子等优点,因此对粮油检化验人员具有很大吸引力。但该仪器的准确度和精密度如何?与经典方法相比是否在同一水平?这是大家甚为关切的问题。为此我们选择了油菜籽为样品,用抽提法与核磁共振法进行了对比试验。经过对38个样品的反复测试以及数理统计分析,认为NH5110核磁共振含油量测定仪有较高的准确度与精密度。现将我们的测试结果简述如下。     

NH5110核磁共振含油量测试仪标准样品管选择

本文对提高NH5110核磁共振含油量测试仪的测试准确性关键问题——标准样品管选择方法进行分析,提出一种交叉测试筛选法,以选出与索氏抽提法测定的标准含油率相符的标准样品管,以此大幅提高测试准确性,并举实例阐述,验证结果。     

酸水解法与自动索氏抽提法测定人造奶油脂肪含量的差异研究和方法改进

采用酸水解法和自动索氏抽提法测定6种不同人造奶油试样的脂肪含量,并对自动索氏抽提法进行改进,对不同方法的结果差异进行分析和研究。结果表明:酸水解法的实验结果偏低;且酸水解法和自动索氏抽提法对人造奶油脂肪含量的测定存在显著差异,采用自动索氏抽提法更合适。同时,对自动索氏抽提法进行改进,实验结果准确度高,其标准差为0.12,均值标准误差为0.03,说明改进自动索氏抽提法重现性好;且改进法对实验具有显著的影响。采用改进自动索氏抽提法,抽提纸筒可循环使用12次,有效降低了实验成本。     

滤袋法测定油料及粕含油量的研究

研究滤袋法测定油料及粕含油量的最佳条件,比较该法与传统索氏抽提法测定油料及粕含油量的差异。以油菜籽为研究对象,采用正交实验设计,确定滤袋法测定含油量的最佳条件为提取温度90℃、提取时间90 min、选用2号溶剂。测定了6个大豆、6个油菜籽、6个花生、14个豆粕、12个棉籽粕、19个菜籽粕样品含油量,滤袋法与索氏抽提法实验结果没有显著差异且相关性良好。因此,滤袋法可以代替索氏抽提法进行含油量的测定。     

残渣法测定油菜籽中的含油量

油菜籽是我国重要的油料作物之一,含油量是衡量油菜籽质量好坏的重要品质指标。目前测定含油量采用的是传统的索氏抽提法,一次只能处理一个样品,效率较低,不适用于大量样品的检测。在检测国家油菜籽会检的批量样品时,采用残渣法测定油菜籽的含油量,并将残渣法与索氏抽提法测定结果进行了比较,测试了残渣法的稳定性,发现该法可大大提高检测效率,并具有准确度高、重现性好、污染小的特点,适用于批量油菜籽含油量的检测。     

折光法快速测定油炸方便面含油率的研究

介绍了折光法快速测定油炸方便面含油率的原理 ,采用正交试验法对影响其精确度的4个因素进行了综合分析 ,确定了其最佳组合为 :细度 12 0目 ,浸泡温度 2 5℃ ,时间 15min ,溶剂与样品比 6∶1。该法与经典的索氏抽提法比较 ,具有速度快、试剂用量少和效率高等优点 ,测出的含油率准确度完全能够满足方便面生产线上油脂检测的要求。     

折光法快速测定油炸方便面含油率的研究

介绍了折光法快速测定油炸方便面含油率的原理，采用正交试验法对影响其精确度的4个因素进行了综合分析，确定了其最佳组合为：细度120目，浸泡温度25℃，时间15min，溶剂与样品比6：1。该法与经典的索氏抽提法比较，具有速度快、试剂用量少和效率高等优点，测出的含油率准确度完全能够满足方便面生产线上油脂检测的要求。     

酸水解法与索氏抽提法测定火腿肠中脂肪含量的比较研究

采用酸水解法和索氏抽提法测定火腿肠中的脂肪含量,结果表明,酸水解法和索氏抽提法检测样品中脂肪的含量分别为12.05g/100g、11.91g/100g,通过t值检验得知,两种方法无明显差异,但由于索氏抽提法的相对误差和变异系数比酸水解法的值小,因此,索氏抽提法的准确度和精确度较高。     

索氏法提取和测定油茶籽油的条件优化

除富含不饱和脂肪酸的茶油外,油茶中还含有茶多糖、茶皂素、茶多酚等多种生物活性成分。以油茶生物活性物质的提取和制备为前提,本研究以简单、有效地提取茶油为目标,以油茶籽含油率为指标,在索氏抽提法单因素实验基础上,选择提取时间、提取温度、提取溶剂种类和单次样品重量为影响因素进行正交优化实验。结果表明,油茶索氏提取的最佳条件为:提取时间6 h、提取温度80℃、有机溶剂丙酮、单次样品重量4 g。该条件下茶籽含油率达43.24%±0.53%。该条件下测得4种油茶整籽和种仁的含油率从高到低依次为广宁红花油茶、普通油茶、小果油茶和高州油茶;广宁红花油茶的整籽和种仁含油率均最高,且饼粕含油率最低,分别为49.7%、67.5%和6.1%。优化后的油茶索氏抽提条件,适用于茶油成分的有效提取和针对油茶籽油的定量分析。     

从微藻中提取粗脂的方法比较

采用改良的酸水解法、异丙醇法、乙醇法、乙醚-石油醚法、索氏抽提法5种方法对3株微藻的粗脂含量进行测定。结果表明,改良的酸水解法与索氏抽提法提取效果稳定、粗脂提取程度高。与索氏抽提法相比,改良的酸水解法大大节省了测定时间,且可以同时对多个样品进行测定,是实验室中对多个微藻样品粗脂含量快速测定的首选方法。     

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。     

Aflatoxins in black tea in Iran

Aflatoxins (AFs) are highly toxic, and carcinogenic secondary fungal metabolites and have been detected in various food commodities. In this regard, 40 black tea samples including domestic and imported black tea were analysed for aflatoxin contamination by high-performance liquid chromatography using a post-column derivatisation procedure (Kobra cell) with fluorescence detection. Samples were randomly collected in 2010 from Tehran markets. The results revealed that 30 among 40 samples were contaminated with aflatoxins (27.5% of the total). Mean AFB1 content was 10.0 ng/g and mean of aflatoxin total was 12.07 ng/g for the 11 contaminated samples.