Comparison of different digestion methods of green and black tea at the Sarajevo market for the determination of the heavy metal content

The content of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn was determined in commercially available black and green tea from Sarajevo market. The concentrations of metals in tea infusion and solutions prepared by applying four digestion methods were determined by using FAAS. The results show that the highest concentration of total metals was obtained after acid digestion in an autoclave. The concentration of metals soluble in water obtained in tea infusion does not exceed maximum allowed values provided by WHO (Guidelines for drinking-water quality, World Health Organization, Geneva, 2011). Among the investigated metals Mn was the highest and ranged from 286 to 334 μg g^?1 in tea infusion of green and black tea, respectively, to 1,078 and 1,528 μg g^?1 total content of Mn in green and black tea, respectively. The concentration of heavy metals in water extracts of tea was distinctly low in comparison with the total content. The concentrations of Cd and Pb were under the determination limit using FAAS. The total content of all determined metals was higher in black tea than in green tea.     

黄山地方茶中重金属浸出规律及健康风险评价

以五种黄山地方茶为研究对象,考察了浸泡次数、浸泡时间和浸泡温度对茶叶中重金属Pb、Cu、Zn、Cd和Mn浸出的影响,并对人体健康风险进行了评价。结果表明,五种茶叶中Pb和Cu含量低于国家标准,五种重金属总浸出量与浸泡次数、浸泡时间和浸泡温度均成正相关关系,弃除浸泡1 min的茶汤可除去茶叶中1.75%~28.28%的重金属,三次浸泡后五种重金属通过茶汤饮用所产生的健康风险水平大小顺序为Cd>Mn>Cu>Zn>Pb,均不会对人体健康构成明显的危害。      

忍冬茶及其加工过程中氨基酸和微量元素分析

目的:考察忍冬茶及其加工过程中氨基酸、微量元素含量的变化情况。方法:采用L-8800型全自动氨基酸分析仪分析忍冬茶及其加工过程中氨基酸种类及其含量的变化情况;采用火焰原子吸收光谱法测定铜、锌、铁等9种微量元素的含量。结果:忍冬茶中含有17种氨基酸且含量丰富,加工前后17种氨基酸的种类没有变化但含量都有所增加;加工后微量元素锌、铁、锰的含量增加,铜、铅、铬、镍、砷的含量降低。忍冬茶经过冲泡后有害金属元素铅、镉、镍、砷含量均符合GB2762—2005《食品中污染物限量》中规定的标准。结论:忍冬茶的加工过程增加了氨基酸和多种有益微量元素的含量,降低了多种有害金属元素的含量,有害金属元素含量均符合GB2762—2005《食品中污染物限量》中规定的标准,表明忍冬茶加工工艺可行,饮用安全。      

Determination of essential mineral concentrations in some turkish teas and the effect of lemon addition

Essential elemental concentrations of Turkish black, green, and earl grey tea infusions were determined with and without added lemon. Daily percentage elemental intake values from these 3 teas with and without lemon addition were calculated based on Recommended Dietary Allowances (RDA). Calcium (Ca), cobalt (Co), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), sodium (Na), selenium (Se), and zinc (Zn) concentrations were increased after lemon addition. The chromium (Cr) concentration was decreased in green and earl grey teas and increased in black tea after lemon addition. The manganese (Mn) concentration was increased in green tea and decreased in black and earl grey teas after lemon addition. The phosphorus (P) concentration was increased in earl grey and green teas, and decreased in black tea after lemon addition. The daily intake value of Mn was found above the RDA value.     

微波消解-ICP-AES法测定泰顺茶叶中的微量元素

用硝酸-H2O2作消解剂进行微波消解,以电感耦合等离子体发射光谱法测定泰顺地区6 种茶叶中的Fe、Mn、Zn、Cd、Cu、Se、Pb、Co、Sn、V、Cr、Ni 12 种微量元素含量。结果表明：在优化条件下,茶叶样品中所测元素的加标回收率为92.0%～106.5%,相对标准偏差小于5.0%,测定方法简便、快速、准确。所测泰顺茶叶样品含有丰富的有益微量元素,Cd、Pb、Cr等重金属元素含量均低于相关的国家限量标准。     

河北烤烟中11种微量元素含量分析

采用微波消解-电感耦合等离子体质谱法,测定河北省石家庄、保定、蔚县3个烤烟主产区不同部位烟叶样品中11种微量元素(Cr,Co,Ni,Se,Mn,Zn,Cu,As,Cd,Pb,Hg)含量.结果表明:烤烟中微量元素含量呈现地域性差异,Mn,Cu,Zn,As和Pb含量差别较大;不同部位烤烟中各微量元素含量呈现规律性分布,Cu在中、上部叶片含量较高,其余微量元素在下部叶含量较高;Mn在测定的元素中含量最高,具有潜在生理毒性的Cu,Cr,Cd,Pb,Ni,Hg,As含量较低,均达到无公害烟叶生产示范区水平.     

电感耦合等离子体质谱法分析菊花茶中微量元素含量及其溶出特性

目的建立电感耦合等离子体质谱法(inductively coupled plasma-mass spectrometry,ICP-MS)同时测定菊花茶中16种微量元素含量的分析方法,并分析其溶出特性。方法以黄山贡菊、昆仑雪菊、杭白菊、胎菊4种市售菊花茶为原料,采用ICP-MS测定其中Mn、Cu、Zn、Ni、As等微量元素的含量,并按照传统的菊花茶饮用方法对不同浸泡时间及冲泡次数条件下黄山贡菊和昆仑雪菊的元素溶出特性进行研究。使用圆白菜标准参考物质(GBW10014)评价分析方法的准确度。结果 4种菊花茶中12种金属元素含量差异显著(P0.05),其中K、Fe、Se、Cd、Hg含量差异较大;Pb、Cr、Cd、Hg、As重金属元素都未超标;随冲泡次数的增加,菊花茶中微量元素的溶出量与其呈负指数降低;延长浸泡时间有助于营养元素的溶出。实验表明相关系数r均大于0.9986,检出限为1.443E-05~7.325E-03μg/m L,误差率都在1%~10%之间,具有良好的精密度和准确度。结论本研究可为茶饮料的科学加工方法提供可靠的实验依据。     

Metal concentration of wild edible mushrooms in Soguksu National Park in Turkey

Twelve varieties of fruiting bodies of wild edible mushrooms collected in 2002 from Soguksu National Park, Ankara, Turkey were analysed for Pb, Cd, Zn, Fe, Mn, Cu, Cr, Ni, and Co contents by inductively coupled plasma optical emission spectrometry (ICP-OES). Dried samples were dissolved by microwave digestion. The contents of trace metals in the mushroom samples were found in the ranges: 0.7–4.2, 0.31–54.2, 29–146, 138–1714, 10–77, 6–187, not detected–21.6, 0.7–4.2 and not detected–5.2 mg kg⁻¹ for Pb, Cd, Zn, Fe, Mn, Cu, Cr, Ni and Co, respectively. The levels of Pb and Cd analysed in all edible mushroom samples except Agaricus arvensis and Ramaria obtusissima for Cd were found to be lower than the legal limits.     

原子吸收光谱法测定茶叶三种初级形态中微量元素的含量

采用人们习惯的沸水浸泡法对茶叶的初级形态进行分离,应用原子吸收光谱法测定了绿茶和红茶三种初级形态中Zn、Cu、Fe、Ca、Mg、Mn、Ni、Pb的含量,计算出微量元素的溶出率和残留率并作了讨论。结果表明,绿茶和红茶三种形态中8种微量元素含量及其微量元素的溶出率、残留率各有差异,实验中样品的回收率为87.1%~102%。     

江西抚州烟区土壤及烟叶重金属污染状况评价

为了弄清江西抚州烟区土壤和烟叶中As、Cd、Cr、Cu、Ni、Pb、Zn和Hg等重金属含量和污染状况,运用内梅罗指数和相关分析法,对这些重金属元素在土壤和烟叶中的含量进行了测定。结果表明,该烟区土壤中重金属含量总体上低于我国土壤二级标准（GB15618-1995）,但其污染程度已处于警戒线水平,Cd和Hg为烟区土壤主要风险因子。土壤和烟叶中重金属含量顺序分别为Zn> Pb> Cr> Cu> Ni> As> Cd> Hg和Zn> Cu> Pb> Cd> Cr> Ni> As> Hg,土壤中Hg、Cd、As和烟叶中Ni、Cr变异系数均较大。烟叶中重金属富集系数顺序为Cd> Zn> Cu> Hg> Ni> Cr> Pb> As,烟叶Cd富集系数高达11.67,表明烟草属于Cd强烈富集作物。     

贵州云雾茶园土壤高含量重金属和砷在茶叶中的积累与浸出特征

为了研究土壤高含量重金属和砷在茶叶中的积累与浸出行为,选择贵州省云雾土壤高含量重金属和砷茶园,采集了土壤和茶叶样品各46个,对土壤-茶叶-茶汤系统重金属和砷进行分析。结果表明：云雾茶园土壤重金属Cd、Hg和As均有部分超出土壤二级标准限量值,超标率分别为80.4%、69.6%和8.7%,该茶园土壤存在严重的Cd和Hg污染。但是,茶叶和茶汤的重金属和砷并未超标,茶叶对不同土壤重金属和砷的富集能力为Cu＞Cd＞Hg＞Pb＞Cr＞As,茶叶-茶汤系统重金属和砷浸出率最高的元素为Hg,不同重金属和砷的浸出率为Hg＞As＞Cu＞Pb＞Cd＞Cr,Hg和Cu在土壤-茶叶-茶汤系统具有较大富集系数和浸出率。     

决明茶中金属离子含量的测定

采用原子发射光谱法分别测定了决明种子及决明茶中K、Na、Ca、Mg、Cu、Zn、Fe、Mn和Cr、Ni、Pb、Hg、Cd等十七种金属元素的含量,并对其结果进行了分析。结果显示,决明种子中含有丰富的宏量元素Mg、K、Ca、P,决明茶中金属元素的含量高低顺序为:K>Mg>Ca>S>P>Na>Fe>Al>Cr>Zn>Mn>Pb>Cu>Ni>As>Cd>Hg,测定结果对进一步研究微量元素含量与决明茶保健效能之间的关系提供了有用的数据。     

红紫芽品种的茶类适制性研究

以不同季节红叶1号、红叶2号、丹妃三个红紫芽品种（系）为供试原料制成绿茶、白茶和红茶,通过茶叶品质分析及感官审评方法综合评价了红紫芽茶树品种（系）的茶类适制性。结果表明,同一品种（系）制成的绿茶和白茶理化成分含量高于对应的红茶。绿茶中各理化成分含量最高,可溶性糖含量三季平均为4.24%~4.69%,而红茶则为3.54%~3.96%。氨基酸含量在白茶中高于绿茶和红茶,白茶中含量达3.40%以上,而红茶和绿茶中含量在3%左右。红紫芽绿茶中花青素含量夏季>秋季>春季,夏季含量为0.086%~0.115%;除了春季白茶检出痕量的花青素外,其余不同季节的白茶和红茶均未检出花青素。感官审评结果表明,白茶普遍具有优雅、浓郁的花香或果香,滋味甜醇鲜爽的特点;红茶普遍具有甜香浓郁、滋味甜醇鲜爽的特点;绿茶品质成分丰富,汤色呈红紫色。研究认为,红紫芽茶更适合制作红茶和白茶,而制成的绿茶则可以作为一种新型特异茶饮进行推广。本研究为红紫芽茶的深入利用提供了理论基础和实践依据。     

Cadmium,lead and some other trace elements in Larch Bolete mushrooms (Suillus grevillei) (Klotzsch) Sing., collected from the same site over two years

The aim of this study was to examine the status of some trace metals accumulated in the flesh of Suillus grevillei mushrooms collected from the same site over two successive years. Total Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn contents of fruiting bodies were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES) with ultrasonic cross-flow nebuliser. A difference (p < 0.05) was found in the contents of Cd, Cr, Cu, Fe, K, Na, Ni, Pb, Rb and Sr in caps and Fe, Na, P and Rb (p < 0.05) in stipes (Ag, Cd, Co, Cr, Ni and Pb were not determined in stipes). Natural fluctuations in trace elements’ content of Suillus grevillei collected from the same site over time is a variable that needs to be considered when assessing minerals’ nutritional status of mushrooms.     

北京市售大米重金属含量监测及膳食风险评估

监测市售大米重金属含量,为北京市食品安全风险评估提供参考和数据支撑,采集了市售大米样品537件,分析其9种重金属(Cd、Cr、Cu、Fe、Mn、Ni、Pb、Sr和Zn)含量。采用内梅罗综合污染指数法评价市售大米的重金属污染水平,采用健康风险评价模型进行食用安全评估。结果如下:大米Cd、Cr、Cu、Fe、Mn、Ni、Pb、Sr和Zn含量平均值分别为0.02、0.02、2.27、2.63、9.10、0.15、0.07、0.17和14.27 mg/kg。大米重金属污染程度依次为:PbZnNiCuCdCr,其风险等级依次为:CuZnCdPbCrNi。结果表明,大米重金属的内梅罗综合污染指数较低,表明当前北京市售大米整体状况较好、处于安全水平;大米重金属对儿童的THQ贡献率高于成人,相关部门应加强有毒重金属监督与相应膳食指导。     

不同地区野山茶中微量元素的浸出率研究

用干法和沸水分别制备红河州4个县市的野山茶样品,并通过火焰原子吸收法测定其中的Mn、Cd、Cr、Cu等微量元素,RSD值为0.07%～1.69%,回收率在98.7%～116.4%之间。从实验结果计算获得测定的微量元素的浸出率,并对比两种不同浸泡方式的浸出率,浸出率在0～37.44%之间变化;除未检测出的元素外,Fe的浸出率是最低的,通过分析得出在野山茶以及茶水中含有对人体有益的Mn、Zn等微量元素。茶水中不含有Pb、Cd等有害元素,是一种安全的天然饮品。     

福建省地产茶叶中14种元素的分析与研究

目的了解福建省不同地区不同茶叶中铅、砷、铜、铁、锰、锌、镉、铝、硒、镍、铬、钴、锡、铋等14种元素的含量分布,为茶叶资源的开发利用提供科学依据。方法从福建省主要产茶地区的产地和市场随机抽取9个茶叶品种共112份样品,用微波消解-电感耦合等离子体质谱法(ICP-MS)测定样品中14种元素含量。结果 9种茶叶中14种元素的含量水平分别为:锰135～1 797 mg/kg,铝69～1 126 mg/kg,铁37～371 mg/kg,锌3.93～90.05 mg/kg,铜2.25～43.66 mg/kg,镍0.95～7.40 mg/kg,铅0.29～5.45 mg/kg,铬0.10～2.39 mg/kg,钴0.018～0.67 mg/kg,硒0.020～0.68 mg/kg,镉0.014～0.24 mg/kg,砷0.023～0.30 mg/kg,锡0.010～0.49 mg/kg,铋0.006～0.073 mg/kg,铅合格率为99.1%,铬、镉、砷合格率为100%。结论福建省地产茶叶中都富含锰、铝、铁、锌、铜。铬、镉、砷、铅等有害元素污染水平较轻,且不同地区不同茶叶中元素含量存在差异。     

Levels of essential and non-essential metals in leaves of the tea plant (Camellia sinensis L.) and soil of Wushwush farms,Ethiopia

Five tea clones of the Camellia assamica variety grown in Wushwush tea plantation farms, Ethiopia, were analyzed for their contents of essential, non-essential and toxic metals (K, Ca, Mg, Fe, Mn, Cu, Zn, Na, Cd and Pb) by atomic absorption flame emission spectroscopy. Both the tea leaves and the soils of the study farms showed similar accumulation patterns in their contents of the studied macronutrients. Among the macronutrient metals, K was the most abundant element in the tea leaves (17.7–24.8 mg/g) and the soils (7.14–9.73 mg/g). Mn was the predominant micronutrient heavy metal in the tea leaf tissues ranging between 501 and 1281 mg/kg. Level of Fe (29.6–100 mg/kg) in the leaf tissue was found to be the second most abundant micronutrient next to Mn whereas concentrations of Cu and Co were relatively lower both in the soil and tea samples. The toxic heavy metals Pb and Cd in the leaf tissues were present at levels too low to be detected by the analytical technique used in this study. The soils were found to be acidic (pH 5.04–5.49) with high organic matter (5.48–6.02%). Fe was the most abundant metal followed by Mn, Na and Zn in the soils. Unlike the tea leaves, the soils were found to contain traces of the toxic metal, Cd (0.02–1.10 mg/kg). The levels of most of the metals determined in this study compared well with those reported for tea leaves from some other parts of the world.     

湘西产猕猴桃重金属含量分析及矿物质营养价值评价

目的了解湘西产猕猴桃中重金属污染状况及评价猕猴桃中矿物质的营养价值。方法从湖南湘西地区采集5种猕猴桃,经消解处理,用电感耦合等离子体质谱仪、原子荧光光度计、可见分光光度计测定其中重金属和矿物质的含量,并根据食品中污染物限量和中国居民膳食营养素参考摄入量分别对重金属和矿物质进行评价。结果湘西产猕猴桃中常量元素都以钾含量最高,达到2.52~3.96 mg/g,而钠含量极低,仅为1.08~4.67 mg/kg。在5种猕猴桃中湘西野生的铁、锌含量最高,湘西东红的锰、铜含量最高,凤凰红心的铬、硒含量最高。5种猕猴桃中铅含量为0.0037~0.019 mg/kg,镉含量为0.00070~0.0024 mg/kg,铅、镉、砷和汞的含量均处于较低水平。结论湘西产猕猴桃中铅、镉含量均低于国家标准规定的限量。在正常推荐食用量的情况下,5种猕猴桃中的矿物质无过量摄入风险。猕猴桃能为人体提供丰富的钾、铜、铬,将它们与磷、钙、铁、锌、硒含量较为丰富的食物搭配食用能使各种矿物质总体上摄入更加充足平衡。     

Trace metals and flavonoids in different types of tea

The mineral and flavonoid contents of commercially available different types of teas (premium black, flavored black, green, and fruit tea) and the infusions produced from them were determined. Studied teas differed in the contents of elements between their raw materials and infusions. Iron and copper exhibited the lowest efficiency of extraction by hot water. For the most popular black tea brand (Lipton® Yellow label) the efficiency of metal extraction decreased in the order: Co>Mn>Ni>Zn>Cu>Fe. Flavored black Citrus tea infusion had the highest content of Co and Ni, while Yellow label and Green Indonesia are a good source of Fe, Mn, and Zn. Flavonoids were predominantly present as glycosides. Rutin was present at much higher levels in black and green teas. Significant amounts of naringin and hesperidin were determined in tea infusions with citrus aromas or fruits.