NaCl胁迫下鲜烟叶中多酚物质含量及PAL和PPO活性变化

为探讨NaCl胁迫对烤烟多酚物质含量的影响,以烤烟NC89为供试品种,在营养液砂培盆栽种植条件下经含350、700 mmol/L NaCl的1/3浓度Hoagland营养液根部胁迫处理,检测分析了植株叶片中多酚物质含量和苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)活性的变化。结果表明,NaCl胁迫处理2 d时叶片类黄酮含量明显增加,处理6 d时绿原酸含量开始增加,处理8 d时芸香苷含量明显增加;花青苷含量随处理时间延长呈先升高后降低的趋势;不同胁迫浓度处理中,绿原酸、类黄酮、芸香苷和花青苷含量以350 mmol/L NaCl处理较高。350 mmol/L NaCl胁迫处理下,PAL活性逐渐升高,并分别与绿原酸、芸香苷含量呈极显著、显著正相关。胁迫处理后PPO活性逐渐升高,且与绿原酸含量有一定相关性。总之,适度NaCl胁迫处理下鲜烟叶多酚物质含量增加,且与PAL活性变化密切相关。     

不同陈化时期烤烟几种酶活性及相关化学成分的分析

对不同陈化时期烤烟中的α－淀粉酶、蛋白酶、脂氧合酶、多酚氧化酶和琥珀酸脱氢酶活性进行了测定,结果表明：α－淀粉酶、蛋白酶和脂氧合酶活性在陈化过程中均表现为前期升高,而后期下降的单峰曲线。烤烟细胞内的多酚氧化酶和琥珀酸脱氢酶活性在陈化前较高,在陈化过程中逐渐下降。不同陈化时期的五种酶活性及有关成分表明,烤烟陈化过程在１２个月到１８个月左右的时间内已基本完成     

吉林晒烟多酚类物质及其相关酶活性的变化动态

选取吉林当地3个主栽晒烟品种研究了不同晒烟品种叶片发育过程中多酚类物质及其相关酶活性的动态变化以及两者之间的关系。结果表明,不同晒烟品种中总酚含量表现为青黄叶＞大叶黄＞大白花,总酚在整个生育期的含量为0.16%~1.2%。不同晒烟品种中总酚含量随着叶龄的增加而提高,在成熟期稍有降低;青黄叶和大叶黄中绿原酸、芸香苷和莨菪亭在叶片发育过程中整体上表现出上升趋势,而大白花中绿原酸、芸香苷和莨菪亭含量呈单峰曲线。各品种中苯丙氨酸解氨酶活性与绿原酸和芸香苷的变化规律相同,多酚氧化酶活性和过氧化物酶活性呈单峰趋势。在烟叶生长过程中,各晒烟品种中苯丙氨酸解氨酶活性与绿原酸、芸香苷、莨菪亭和总酚的变化呈正相关,且与绿原酸和芸香苷达到显著水平;多酚氧化酶活性变化与绿原酸、芸香苷、莨菪葶和总酚的相关性表现为负相关,但未达到显著水平;过氧化物酶活性与绿原酸、芸香苷、莨菪葶和总酚呈正相关,且与总酚达显著水平。由此可见,苯丙氨酸解氨酶和过氧化物酶与多酚类物质之间有显著的相关性,可以通过调节这两种酶的活性来控制多酚的含量,从而改善烟叶质量。     

白肋烟种子萌发的生理生化动态研究

以TN86种子为材料,分析了白肋烟种子萌发特征及有关活性酶与相关物质的变化动态。结果表明,呼吸强度、淀粉酶与可溶性总糖和还原糖、蛋白酶与总游离氨基酸、脂肪酶与脂肪酸,以及过氧化物酶(POD)、多酚氧化酶(PPO)、可溶性蛋白质、脯氨酸(pro)、丙二醛(MDA)等的活性或含量都随萌发进程呈上升趋势,其间虽有所波动,但最高峰值期大都在第84-168h之间,仅POD与PPO活性和MDA含量在萌发中期才开始明显上升,直至萌发结束时达高峰值。淀粉酶、蛋白酶、脂肪酶活性与各自催化水解的产物含量呈极显著正相关;而粗脂肪含量随萌发进程而下降,与脂肪酸呈极显著负相关。萌发集中在48-72h,发芽势90%,同步指数0.92。萌发动态符合Logistic生长曲线方程。     

打叶复烤协同醇化对四川凉山烤烟烟叶多酚含量的影响

研究了不同打叶复烤关键参数(a1为一润出口温度,a2为复烤一区温度,a3为复烤二区温度,a4为复烤三区温度,a5为复烤四区温度)和醇化时间下四川凉山烤烟烟叶绿原酸、新绿原酸、4-O-咖啡基-D-奎尼酸、莨菪亭、芸香苷、山萘酚糖苷、多酚总量的变化规律。结果表明:(1)一润出口温度对多酚总量的影响显著,并呈正相关性,复烤一~四区温度与多酚含量无显著相关。(2)绿原酸、新绿原酸、芸香苷、山奈酚糖苷、总酚含量随醇化时间的延长总体上呈降低趋势,4-O-咖啡基-D-奎尼酸、莨菪亭含量随醇化时间的延长总体上呈增大趋势。(3)醇化时间对多酚含量的影响大于打叶复烤。(4) B0~B5、C0~C5、X0~X5烟叶香气感官质量最优的打叶复烤参数为a1为60℃、a2为50℃、a3为79℃、a4为67℃、a5为70℃、醇化时间12个月,此时烟叶多酚含量、感官质量均为较优水平。     

海拔对浓香型烤烟多酚类物质组成的影响

为了构建不同产区烟叶的指纹图谱,快速区分烟叶产地,以浓香型主产烟区的8个省区68份烤烟C3F为材料,采用描述统计和相关分析方法,研究了浓香型烤烟主产区海拔对烟叶多酚类物质组成的影响。结果表明:1不同产区烟叶中多酚含量集中度较高,略呈正向偏态分布;28省区范围内(海拔高度17~1298 m)绿原酸和莨菪亭占多酚含量的比例与海拔高度成负相关和极显著负相关,芸香苷占多酚含量的比例与海拔高度成极显著正相关;3华中地区(海拔高度64~1044 m)烤烟绿原酸和莨菪亭占多酚含量的比例与海拔高度成极显著和显著负相关,芸香苷占多酚含量的比例与海拔高度成极显著正相关;4芸香苷较绿原酸和莨菪亭有更宽的紫外吸收波长和更强的吸收能力,可能是导致海拔高度越高烟叶中芸香苷占多酚含量的比例越高的原因。     

兰州百合鳞茎冷藏保鲜过程中碳水化合物含量及淀粉酶活性的变化

以兰州百合为试材,采用紫外-可见分光光度法测定了-2 ℃冷藏保鲜过程中百合鳞茎内可溶性糖、还原糖、淀粉的含量与淀粉酶活性的动态变化,分析了碳水化合物含量与淀粉酶活性之间的关系。结果表明,在-2 ℃、60 d的冷藏保鲜期内,随着冷藏时间的延长,兰州百合鳞茎内淀粉含量明显下降,其下降幅度达62.29%,可溶性糖与还原糖含量呈上升趋势,分别上升了2.22%和1.39%。β-淀粉酶是兰州百合鳞茎中的主要淀粉酶,其活性随冷藏时间的延长而有所降低,α-淀粉酶的活性随冷藏时间的延长先降低后升高,总淀粉酶在高活性的基础上整体呈现降低的趋势。相关性分析表明,鳞茎中碳水化合物含量及淀粉酶活性之间的相关性差异水平有所不同。总淀粉酶、β-淀粉酶活性与可溶性糖、还原糖含量具有极显著负相关性,而与淀粉含量具有极显著正相关性。可溶性糖和还原糖含量的增加与低温诱导下淀粉在β-淀粉酶的作用下分解有关。     

油茶籽多酚提取物生物活性的研究

山茶籽油是我国特色食用油,具有多种活性,多酚是其主要功能成分之一。为探究油茶籽多酚的活性特点,研究比较了15个油茶籽多酚样品和5种非油茶植物多酚(肉桂多酚、苹果多酚、葡萄皮多酚、紫锥菊多酚、石榴皮多酚)抑制脂氧合酶(lipoxidase, LOX)、环氧合酶-2(cyclooxygenase 2,COX-2)、 α-葡萄糖苷酶、α-淀粉酶和胰脂肪酶活性,羟自由基清除率、超氧阴离子清除率,抗脂质氧化活性,并通过“蓝精灵”实验评估了多酚对果蝇肠炎的抑制活性。结果表明：油茶籽多酚提取物对几种酶均有抑制作用,油茶籽多酚提取物对果蝇肠炎和LOX活性的抑制作用显著高于非油茶籽多酚提取物;相关性分析结果显示,多酚抗LOX活性和抗果蝇肠炎活性之间呈极显著正相关(r=0.725,P<0.01)。油茶籽多酚是α-葡萄糖苷酶选择性抑制剂,其抗炎效果强于非油茶籽多酚,抗氧化、抑制LOX活性可能是油茶籽多酚抗肠炎机制之一。     

面包生产中的酶

０　前言面包生产中的酶有三个来源：面粉中含有的酶类,与酵母和乳酸菌代谢有关的酶类,人为添加的酶制剂。酶在面包形成风味过程中有重要作用,酶活性的不同会带来不同风味的面包。酶活性从面粉水合后开始,一直持续到烘烤温度使蛋白质结构发生破坏时停止。和面包风味形成有关的三个酶体系为：淀粉酶（主要为α－和β－淀粉酶）、蛋白酶和脂肪氧合酶。虽然除此之外还有其它一些酶（如转化酶、氧化酶、脂酶）参与,但作用很小。下面着重讨论淀粉酶、蛋白酶和脂氧合酶对面包风味形成的贡献情况。１　淀粉酶α－淀粉酶能水解淀粉、直链淀粉、…     

不同部位雪茄烟叶晾制过程中多酚、色素及相关酶活性的变化

为明确晾制过程中雪茄烟叶多酚类物质和质体色素的降解规律以及相关酶活性的动态变化,以德雪1号为试验材料,研究了不同部位烟叶晾制期间多酚类物质、质体色素及相关酶活性的变化规律,并进行了相关分析。结果表明,不同部位雪茄烟叶中多酚类物质含量主要表现为中部叶 > 下部叶 > 上部叶,其中各部位绿原酸含量均呈下降趋势,而芸香苷和莨菪亭含量均呈现单峰曲线。各部位质体色素含量随着晾制过程的推进而逐渐降低,整体表现为上部叶 > 中部叶 > 下部叶。各部位烟叶中脂氧合酶、苯丙氨酸解氨酶、多酚氧化酶、过氧化物酶等酶活性均呈先增后降趋势。相关分析表明,晾制期间各部位多酚氧化酶活性与多酚、色素含量呈正相关,且与绿原酸和β-胡萝卜素达到显著水平;苯丙氨酸解氨酶活性与多酚、色素含量呈负相关,且与绿原酸达到显著水平。过氧化物酶与脂氧合酶、苯丙氨酸解氨酶、多酚氧化酶均呈显著正相关,因此在晾制过程中合理调控各类酶活性,可以控制多酚类物质及质体色素含量,有利于提高雪茄烟叶调制特性。     

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。     

Content of selenium in fishes,caught in lakes in Buriatia

Study of selenium accumulation by fish of Buryatia shows relatively high accumulation level for the Baikal lake (213-513 mcg/kg) contrary to the lakes of Baunt and Selenginsk regions of the republic (84-227 mcg/kg). Selenium deficiency in Baunt region is also confirmed by low selenium levels in meat of native origin (39-95 mcg/kg). Among different tissues and organs the lowest selenium levels are typical for muscles, the value increasing in the row: muscle < skin < air bladder < scales < fin < liver < roe.     

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。