苹果品种和酿造工艺对苹果酒中酚类物质的影响研究

研究不同苹果品种及加工工艺与苹果酒中最终酚类物质的含量和种类的关系,了解不同苹果酒中酚类物质含量的差异.选用甘肃天水提供的两种不同工艺的6款苹果酒样,测定其中的总酚、酚酸及黄烷-3-醇的含量.苹果酒的总酚含量(以没食子酸计)较高,3种苹果酒中的主要酚类物质中,酚酸主要以原儿茶酸、绿原酸、p-香豆酸以及咖啡酸为主;黄烷-3-醇以儿茶素和表几茶素居多.结果表明,不同苹果品种之间酚类物质的含量及类别差异很大,相同品种的苹果酒中多酚的构成及含量会受到酿造工艺的影响.     

苹果酒中酚酸、黄烷-3-醇的检测

以小国光(Ralls)和富士(Fuji)及其所酿制的新鲜苹果酒为试验材料,采用反相高效液相色谱法测定分析苹果原汁、发酵中酒样和苹果成品酒中11种酚酸、5种黄烷-3-醇的含量。结果表明:苹果和苹果酒中存在4种酚酸(原儿茶酸、绿原酸、咖啡酸、对-香豆酸)、2种黄烷-3-醇(儿茶素和表儿茶素);不同品种的苹果原汁和苹果成品酒中酚类物质的含量都存在显著差异。其中,小国光苹果和小国光苹果酒中的酚类物质总含量较高;对于每个品种,绿原酸都是最主要的酚酸类物质,含量最高的黄烷-3-醇类物质都是表儿茶素。随着发酵过程的进行,苹果酒中酚类物质的含量有不同程度的增加。其增加趋势为S型曲线,即先平缓再较快再平缓。     

RP-HPLC-DAD法测定茶叶籽油酚类化合物

建立同时分离、检测茶叶籽油中酚类化合物组分和含量的高效液相色谱法。比较了流动相组成的影响,选择合适的乙酸加入量,建立最优梯度洗脱条件。结果表明,14种酚类物质在该条件下能够得到较好的分离,各物质的线性相关系数均在0.99以上。运用该方法从茶叶籽油中共检测到13种酚类化合物,包括5种酚酸、3种黄酮类和5种儿茶素类,含量分别为46.8、21.72、40.16μg/g;其酚酸类主要为肉桂酸和咖啡酸,黄酮类主要为山奈酚、槲皮素和芦丁,儿茶素类主要为儿茶素。该方法准确、可靠,适用于茶叶籽油中酚类化合物分析。     

果胶酶及浸渍处理对苹果酒多酚组分的影响

为了探究果胶酶及浸渍处理对苹果酒多酚组分和品质的影响,用4种不同方式(清汁发酵不加酶、清汁发酵加酶、浸渍发酵不加酶、浸渍发酵加酶)酿造苹果酒,并测定其在发酵过程中的多酚组成、理化指标和抗氧化指标。结果表明,果胶酶和浸渍处理分别能够增加和降低苹果酒酸度,对酒精度没有显著影响。果胶酶和浸渍处理能够显著提高苹果酒中总酚的含量。共检测出9种多酚组分,包括酚酸类的没食子酸、绿原酸、咖啡酸、对香豆酸、阿魏酸和黄酮类的儿茶素、金丝桃苷、根皮苷和根皮素。果胶酶添加能促进绿原酸和根皮苷降解生成咖啡酸和根皮素,浸渍处理能促进果渣中酚类物质浸出,从而提高酒样中多酚组分含量,提高酒体抗氧化活性。果胶酶和浸渍处理对苹果酒品质有显著提高。     

不同品种苹果果实主要酚类物质含量的研究

用高效液相色谱仪测定了不同品种苹果果实绿原酸、儿茶素、表儿茶素、根皮素和槲皮素等主要酚类物质的含量。结果表明,不同品种苹果果肉酚类物质总量以富士和新红星最高,金冠最低。富士苹果果肉酚类物质以绿原酸为主,新红星和王林苹果果肉以表儿茶素为主。不同品种苹果果皮酚类物质总量以新红星最高,各品种苹果果皮酚类物质总量均高于果肉。果皮中酚类物质以黄烷-3-醇类为主。     

燕麦醋中多酚类的含量和组分分析

对燕麦为主要原料的山西老陈醋中的酚类物质的含量和种类进行了分析。分别选用乙酸乙酯、乙醇和水为溶剂,采用高效液相色谱法定性定量测定燕麦醋中常见酚类物质含量。结果表明燕麦醋的乙酸乙酯提取物含有的酚酸种类最多,没食子酸在乙醇提取物中的含量较高,儿茶素仅在乙醇提取物中检测到。其它酚类物质含量,均是在乙酸乙酯提取物中最高。而水提物中酚酸种类较少,含量也不高。     

苹果酒的酶促与非酶促氧化褐变研究

通过对苹果、苹果酒中酚类物质、多酚氧化酶(PPO)的测定表明,氧化褐变贯穿苹果酒生产的始终;酶促氧化在苹果酒生产加工前期占优势,非酶促氧化则一直存在。以(-)-表儿茶素为例,实验中比较了这2种氧化褐变,酶促氧化反应速率是非酶促氧化的约800倍,酶促褐变程度(1.5731/120min)也远大于非酶促褐变(0.4742/316h),且两者的氧化产物也有所不同。苹果酒的氧化褐变是酶促氧化与非酶促氧化综合作用的结果。     

不同原料苹果酒的酿造特性研究

以‘金世纪’单一苹果品种及‘金世纪’、‘嘎啦’、‘澳洲青苹’混合（1∶1∶1）苹果品种为原料酿造苹果酒,并对其进行理化指标、多酚物质、香气成分测定及感官品评。结果表明,两种苹果酒理化指标差异不显著（P＞0.05）;混合发酵苹果酒中的酚类物质总量（61.88 mg/L）显著高于单独发酵苹果酒（56.90 mg/L）（P＜0.05）,其中以原儿茶酸、儿茶素、原花青素、表儿茶素和绿原酸为主。香气主要以醇类和酯类物质为主,两种苹果酒中醇类物质含量分别为216.83 mg/L和78.85 mg/L;酯类以乙酸乙酯、乙酸丙酯、乳酸乙酯和乙酸己酯为主,前三者在混合发酵苹果酒中含量均显著高于单独发酵苹果酒（P＜0.05）,使其香气更加浓郁和复杂。混合发酵苹果酒在澄清度、回味、香气、风味平衡方面更好,但在色泽方面稍差。因此,混合苹果品种发酵更适合于苹果酒的酿造。     

果酒模拟体系中单酚酶促氧化聚合的研究

酚类物质的氧化聚合对果酒(白葡萄酒、苹果酒等)的口感和稳定性均有影响.以黄酮类物质的典型代表儿茶素和酚酸类物质的典型代表绿原酸为研究对象,在模拟体系中通过LC-MS对其酶促氧化聚合进行了研究.结果表明,单酚在酶促下确实会发生聚合,且不同的单酚表现出不同的聚合过程及不同的聚合速度.     

茶多酚保健功能研究

茶多酚（Tea Polyphenots）是茶叶中多酚类物质的总称，包括黄烷醇类、花色苷类、黄酮类、黄酮醇类和酚酸类等。其中以黄烷醇类物质（儿茶素）最为重要。茶多酚又称茶鞣或茶单宁，是形成茶叶色香味的主要成份之一．也是茶叶中有保健功能的主要成份之一。     

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。     

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.     

Heavy metals in vegetables sold in the local market in Jordan

Heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in various vegetables (cabbage, green onion, lettuce, parsley, rocket, spinach, carrot, onion, potato and cauliflower) from the market in Jordan were measured using inductively coupled plasma-mass spectrometry. As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 0.009–0.275 mg kg^?1 wet weight, 0.004–0.060 mg kg^?1, 0.003–0.401 mg kg^?1, 0.105–3.51 mg kg^?1, 0.15–1.15 mg kg^?1, 0.93–14.39 mg kg^?1, 0.044–0.702 mg kg^?1, 0.072–0.289 mg kg^?1 and 2.23–6.65 mg kg^?1, respectively. Parsley, followed by spinach, contained the highest concentration of heavy metals. Onion contained high levels of toxic heavy metals. The content of Cu in parsley and spinach and Pb in onion exceeded the Codex limits. However, the daily intake of heavy metals from the tested vegetables was lower than the maximum limits for allowable intake.     

降低劳力输出的同时提高整经生产率

在劳动成本很高的国家,纺织厂遇到了难以找到合适的工人和辅助人员以从事繁重的筒子搬运工作的问题,而且这种问题日益严重。因为按照不同的纱线支数和筒管尺寸,成吨的纱线筒管必须由人工尽快地搬运到位。