Chemometric approach to evaluate trace metal concentrations in some spices and herbs

Herbs (mint, thyme and rosemary) and spices (black pepper, chili pepper, cinnamon, cumin, sweet red pepper and turmeric) were analysed using atomic spectrometry and then subjected to chemometric evaluation in an attempt to classify them using their trace metallic analyte concentrations (As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Sr and Zn). Trace metals in acid digests of these materials were determined using both inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. The chemometric techniques of principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) were used for the classification studies. These herbs and spices were classified into five groups by PCA and CA. When the results of these techniques were compared with those from LDA, it was found that all group members determined by PCA and CA are in the predicted group that 100.0% of original grouped cases correctly classified by LDA.     

Evaluation of trace metal concentrations in some herbs and herbal teas by principal component analysis

Sixteen trace metallic analytes (Ba, Ca, Ce, Co, Cr, Cu, Fe, K, La, Mg, Mn, Na, Ni, P, Sr and Zn) in acid digests of herbal teas were determined and the data subjected to chemometric evaluation in an attempt to classify the herbal tea samples. Nettle, Senna, Camomile, Peppermint, Lemon Balm, Sage, Hollyhock, Linden, Lavender, Blackberry, Ginger, Galangal, Cinnamon, Green tea, Black tea, Rosehip, Thyme and Rose were used as plant materials in this study. Trace metals in these plants were determined by using inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. Principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) were used as classification techniques. About 18 plants were classified into 5 groups by PCA and all group members determined by PCA are in the predicted group that 100.0% of original grouped cases correctly classified by LDA. Very similar grouping was obtained using CA.     

Chemometric analysis of minerals and trace elements in raw cow milk from the community of Navarra,Spain

The concentrations of protein, fat, five minerals (Na, K, P, Ca and Mg) and nine trace elements (Fe, Zn, Cu, Mn, Se, Al, Cd, Cr and Pb) have been determined in 347 samples of raw cow milk from the community of Navarra, north Spain, using infrared analysis, atomic absorption spectrometry (flame and electrothermal atomisation) and inductively coupled plasma atomic emission spectroscopy. A preliminary chemometric study with the use of pattern recognition methods was carried out in order to characterise, classify and distinguish the different collected samples on the basis of their contents. Principal component analysis (PCA) has permitted the reduction of 16 variables to five principal components which interpret reasonably well the correlations of these studied variables. These variable associations may be attributed to intrinsic (lactogenesis) and other extrinsic factors, such as seasonal variation, animal feeding or geographical situation. Changes in these contents during different seasons were also assessed and consistently interpreted. Linear discriminant analysis (LDA) was used to explore cow milk samples, classifying according to season or geographical location, providing complementary information to PCA. This work shows that PCA and LDA are useful chemometric tools for the multivariate characterisation of raw cows’ milk.     

云南不同区域羊肚菌砷、汞及常量元素分布特征

目的测定云南5个地区同一种菌类(羊肚菌)砷、汞及其他常量元素的含量,并对不同产地的羊肚菌元素分布特征进行判定。方法采用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)检测羊肚菌总砷、总汞、铅、锌等元素含量,采用液相色谱-原子荧光光谱联用法(liquid chromatography-atomic fluorescence spectrometry, LC-AFS)检测羊肚菌中无机砷、有机砷含量;利用主成分分析法对不同区域羊肚菌中元素分布特征进行分析判别。结果云南省境内羊肚菌As、Hg等重金属元素无超标现象,且含有Ca、P等多种有益元素。不同地区的羊肚菌中元素具有各自特征,能够通过主成分分析方法进行菌类产地判别。结论利用菌类多元素、多指标协同分析能够对菌类的产地进行初步判断,但仍需更多的基础水质、降雨、土壤数据进行支撑。     

Evaluation of trace and toxic element concentrations in Paris polyphylla from China with empirical and chemometric approaches

Trace and toxic elements in Paris polyphylla samples were determined by flame and graphite furnace atomic absorption spectrometry following microwave-assisted acid digestion, based on a mixture of nitric acid and hydrogen peroxide. The whole procedure, including sample preparation, digestion and measurements, was successfully validated against CRM GBW07603 (bush twigs and leaves). In order to get a better insight into the elemental patterns, common chemometric approaches to data evaluation, such as principal component analysis (PCA) and hierarchical cluster analysis (HCA), were used as classification techniques. Five significant groups classified by PCA were attributed partly to significant influential sources. HCA revealed five groups of P. polyphylla samples based on their trace and toxic element concentrations.     

基于矿物元素分析对进口泰国、越南、柬埔寨香米产地的鉴定

目的 探讨泰国、越南、柬埔寨3国香米矿物元素含量差异,并对产地进行鉴别。方法 通过电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)测定泰国、越南、柬埔寨3国75份香米中Cr、Ni、Cu、Zn、As、Se、Cd、Hg和Pb 9种矿物元素含量,对测定结果进行差异性分析、相关性分析、主成分分析和Fisher判别。结果 所有样本均未检出Pb,其中Ni、Cu、Zn、As、Se、Cd6种元素在不同国家之间有显著性差异(P<0.05),并且Cu在3个国家之间均存在极显著差异(P<0.01),6种元素相互之间存在一定的相关性。主成分分析中选取了前2个主成分,累计方差贡献率为71.334%。确定Cu、Ni和Se元素是造成不同产地香米矿质元素差异的特征因素。通过Fisher判别建立溯源模型,对越南训练集和验证集判别准确率为100%,而对柬埔寨和泰国的训练集判别准确率达到70%以上,验证集的判别准确率达到80%以上。结论 通过Fisher判别法可较为有效地鉴别泰国、越南、柬埔寨3个国家的香米。     

植物基肉制品营养组成分析与评价

为充分了解国内外市售植物基肉制品营养品质现状,筛选了国内外30种市售植物基肉制品,对其营养组成、营养质量指数(INQ)和营养当量值(NEU)进行了分析,通过相关性分析、主成分分析和聚类分析的方法,建立了植物基肉制品营养素组成综合评价模型,并进行了分级分类评价。结果表明,市售植物基肉制品以植物基鸡块、植物基牛排等半成品为主,营养评价指标主要包括能量(140.85～1 076.00 kJ/100 g)、蛋白质(5.20～25.00 g/100 g)、脂肪(1.00～22.00 g/100 g)、碳水化合物(1.40～24.58 g/100 g)和钠元素(313.00～1 080.00 mg/100 g),有的还特别标识含有膳食纤维、钙元素和铁元素等。聚类分析发现,高蛋白(≥12.00 g/100 g)产品有23种,占比76.67%,以植物基牛排、植物基鸡块为主;低脂肪(≤3.00 g/100 g)产品有植物基香肠和植物基猪肉共2种,占比6.67%;低碳水化合物(≤5.00 g/100 g)产品有11种,占比约36.67%,包括植物基鸡块、植物基猪肉和植物基牛排等。相关性分析显示,植物基肉制...     

Antioxidant capacity and major phenolic compounds of spices commonly consumed in China

The antioxidant capacity, total phenolic content, and major phenolic compounds of a total of 19 commonly consumed spices in China were systematically investigated. Ultra performance liquid chromatography (UPLC) coupled with photodiode array detector (PDA) was used to identify and quantify the phenolic compounds in the spice extracts. Galangal exhibited the highest antioxidant capacity, associated with the highest total phenolic content. Furthermore, galangin was identified as the principal phenolic component and the main contributor to the highest antioxidant capacity of galangal. Spices in the family Rutaceae and Lauraceae possessed very high antioxidant capacity and high levels of phenolics. Generally, chlorogenic acid and rutin were identified as the dominant phenolic compounds in the spice extracts. This study might provide useful information not only for human health, but also for screening new economic natural antioxidants that could be used in foods.     

微波消解在测定食品中微量元素的应用

总结了食品中微量元素测定时常用的样品处理方法,并重点对微波消解食品时样品的取样量、样品预处理的方法、所用溶剂的种类和数量以及加热时间和压力的选择作了阐述,从而为微波消解食品样品提供了操作依据。     

卷烟烟丝中游离态氨基酸的主成分分析和聚类分析

为探索烟丝中游离态氨基酸同卷烟吸味的关系,采用超声波萃取和氨基酸分析仪测定了15种不同品牌卷烟烟丝中的17种游离态氨基酸的含量,并对数据进行了主成分分析和聚类分析。结果表明:该方法可用于不同吸味卷烟的比较和分类;各种氨基酸的含量分布特征能反映不同品牌卷烟的特性,对卷烟刺激性和丰满度的评价及分类有参考价值。     

Multi-element analysis of mineral and trace elements in medicinal herbs and their infusions

Twelve mineral and trace elements (Al, B, Ba, Fe, Zn, Mn, Mg, K, Na, P, Cu, Sr, and Ca) were determined in the herbs and their infusions consumed for medical purposes in Poland such as chamomile (Matricaria chamomilla L.), peppermint (Mentha xpiperita), melissa (Melissa officinalis), sage (Salvia officinalis), nettle (Urtica dioica), linden (Tilia vulgaris) and St. John's wort (Hypericum calycinum). Dry digestion procedure for total concentration and wet digestion procedure for infusions were applied under optimized conditions for dissolution of medicinal herbs. Element concentrations in herbs and their infusions were determined by ICP-OES. The accuracy and precision were verified against NCS DC 73349 - bush branches and leaves certified reference material. The result of total concentrations of elements in herb leaves shows that all herbs contain most of the elements, except K and P, in the μg/g range, and that elemental concentrations varied widely. Moreover, on the basis of experimental results for the extraction efficiencies, the elements in herb infusions were classified into three specific groups: highly-extractable (>55%) including K; moderately-extractable (20-55%) including Mg, Na, P, B, Zn and Cu and poorly-extractable (<20%) including Al, Fe, Mn, Ba, Ca and Sr. The results of analysis were evaluated statistically using ANOVA one-way and three-way analysis of variance, variance correlation test and Spearman's test.     

化学计量学结合气相色谱法对12种植物油判别模型的构建

测定了12种植物油的脂肪酸组成和含量,探讨了利用植物油脂肪酸的指标对不同种类的植物油进行分类和判别的可能性。采用气相色谱法对12种植物油脂肪酸的组成和含量进行测定,利用SPSS 22. 0统计软件进行主成分分析、系统聚类、 K-平均值聚类和判别分析。结果表明：12种植物油的主要共有组成为油酸（15.635%~66.569%）和亚油酸（10.521%~58.227%）,其中棉籽油（16.285%）中单不饱和脂肪酸含量最低,橄榄油（67.628%）中单不饱和脂肪酸含量最高;橄榄油（11.284%）中多不饱和脂肪酸含量最低,核桃油（67.167%）中多不饱和脂肪酸含量最高;12种植物油中不饱和度最小为棉籽油3.235,最大为低芥酸菜籽油14.672。主成分分析降维得到5个主成分,利用主成分分析数据,依次进行聚类分析和判别分析,系统聚类和K-平均值聚类结果一致,可对12种植物油聚类区别,通过判别分析建立了3个典则判别函数,对不同植物油的分类和判别的效果良好。     

澳洲坚果种质果仁主要营养成分分析与评价

以12份澳洲坚果优良种质为试材,通过相关分析与主成分分析等方法,分析不同澳洲坚果种质之间的营养成分差异,挖掘及合理评价现有资源,为澳洲坚果种质资源保护和优异资源的开发利用提供理论依据.结果表明,澳洲坚果果仁的营养成分含量在供试种质之间变化较大,变异幅度在4.60％～24.84％之间,果仁内的变异系数由高到低依次为Ca ...     

微波消解-电感耦合等离子体串联质谱法测定新疆黑枸杞红酒中微量元素的主成分分析

建立电感耦合等离子体串联质谱(inductively coupled plasma tandem mass spectrometry,ICP-MS/MS)分析方法测定新疆黑枸杞红酒中22种微量元素含量,并进行主成分分析.黑枸杞红酒经微波消解处理,采用ICP-MS/MS测定22种微量元素含量,在MS/MS模式下以O2为反...     

25种新疆主栽辣椒品种品质分析

目的 探究新疆主栽辣椒品种的品质差异,并进行干椒样品间的品质综合评价。方法 本研究对25 种新疆主栽辣椒的表型特征和营养指标进行测定,针对品质指标进行数据的统计分析、相关性分析和主成分分析,并对供试样品进行聚类分析。结果 分析各指标间的相关性,结果表明各品种辣椒品质指标之间差异明显,不同品种辣椒制干适性存在区别。通过主成分分析可选取4 个主成分代表25 种辣椒的12 个品质指标,且累计贡献率达到82.275%,较全面地表达辣椒品质的综合信息;通过聚类分析将所有样品分为4 类,与样品的谱系关系基本一致。在25 种样品中筛选出综合排名较高的品种为“线椒10号”“长线1号”、“聚源5号”,制干后营养品质较高且色泽较好。同时高得分品种的品质进行分析,可将果形指数、可溶性糖含量、ASTA色度及蛋白质含量作为干制辣椒品质分析的重要指标。结论 该研究为辣椒干制加工适宜性原料筛选提供了科学依据,有助于辣椒加工制品产业的发展。     

Characterization of Swiss vineyards using isotopic data in combination with trace elements and classical parameters

The objective of this work was to study methods to check the geographical origin of Swiss wines. Authentic grape samples from the vintages 2000 and 2001 were collected in representative locations, and the wines produced from these samples were subjected to isotopic (²H/¹H_ethanol; ¹⁸O/¹⁶O_{wine water}), elemental (Mn, Al, B, Ba, Ca, Fe, Mg, Na, Rb, Sr, Zn) and FT-IR (ethanol, pH, total acidity, volatile acidity, malic acid, fructose, tartaric acid, lactic acid, succinate, citric acid, glycerol, 2,3-butandiol, dry matter and relative density (d₂₀)) analyses. The results showed that the variables ¹⁸O/¹⁶O_{wine water}, strontium, rubidium, and ethanol%, when considered in a monovariate approach, allowed the best discrimination of the geographical origins of Swiss wines. By using a combination of all variables (multivariate approach), Switzerland was divided in four main production zones with a separation power that has never before been achieved. These zones were defined as Tessin, Valais, Romandie and Alemanique. A fifth zone (Graubünden) could be evidenced in vintage 2001.     

不同采收期不同品种莲藕的营养品质变化规律及评价

目的 探究不同采收期不同品种莲藕的营养成分和活性成分的变化规律。方法 选取5个采收期的4个品种莲藕,测定蛋白质、淀粉等指标。采用主成分分析和聚类分析进行综合评价,并建立莲藕品质评价模型。结果 在采收期内,莲藕淀粉含量呈现先上升后下降再上升的趋势,可溶性糖的变化趋势与其相反;总酚含量整体呈现先上升后下降的趋势;蛋白质、膳食纤维等指标呈现不同的变化规律。主成分分析法提取出PC1、PC2、PC3 3个主成分因子,特征值依次为2.274、1.933、1.023,累积方差贡献率达87.170%。不溶性膳食纤维、可溶性膳食纤维、可溶性总糖、淀粉、总酚和总黄酮6个指标可以用来综合评价莲藕营养品质。综合评价发现, 9月采收的八月粉,10月的鄂莲6号,2月的鄂莲10号和鄂莲11号,营养品质较好,优于其他采收期。3月采收的4个品种莲藕的综合营养品质较低。结论 在采收期内, 4个品种莲藕的营养物质动态规律存在一定差异。基于主成分分析和聚类分析的分析方法能够科学评价不同采收期莲藕的综合营养品质,为莲藕育种、加工等提供支撑。     

Analysis of trace elements in southern Italian wines and their classification according to provenance

Wines from three important wine-producing Southern Italian regions (Basilicata, Calabria and Campania) were characterized according to their content in macro-, micro-elements and lanthanides. The elemental composition was used in multivariate statistical analysis to discriminate the wines according to geographical origin. A total of 61 elements were determined in 120 red wines produced in the years 2000-2002, and precisely 40 samples for each region. Results indicated that element analysis provides a good prospect for discriminating wines by regions, even if the element composition is not dependent on the year of production of wine. A Canonical Variate Analysis showed that the discrimination of wines according to their provenance is based on the following elements: Ag, B, Ca, Cd, Eu, Fe, Ga, La, Lu, Mn, Nd, Pr, Sm, Th, Tm, V, Yb, and Zr for Basilicata; Al, B, Fe, Mg, Mn, Ti, Tl, Sc and Zn for Calabria; Ba, Eu, K, I, Rb, and Tl for Campania.     

Bioaccessibility of trace elements and chromium speciation in commonly consumed cereals and pulses

Copper, manganese, and chromium content and their bioaccessibility were determined in commonly consumed cereals and pulses. Copper, manganese, and chromium concentration of these grains ranged from 0.19 to 1.22, 0.46 to 8.12, and 0.02 to 0.11 mg/100 g, respectively. Bioaccessibility of these minerals from the grains ranged from 6.6 to 32.5% (copper), 15.5 to 43.5% (manganese), and 2.66 to 36.4% (chromium). In terms of bioaccessibility of these minerals, pulses provided more than cereals. Speciation analysis of chromium by selective alkaline method demonstrated the presence of the toxic hexavalent chromium in lower concentration than trivalent form.     

Variation of active constituents and antioxidant activity in pyrola [P. incarnata Fisch.] from different sites in Northeast China

The variation of antioxidant activity and active components in pyrola [Passiflora incarnata Fisch.] from eight sites in Northeast China were investigated. Total phenolic and flavonoid contents were determined and varied within the range of 39.66–181.48 mg/g and 2.47–22.11 mg/g, respectively. Antioxidant activities were determined by scavenging activity against DPPH and ABTS, by a reducing power test and by a β-carotene-linoleic acid bleaching test. The IC₅₀ of Tahe samples determined by the DPPH test was 0.106 ± 0.006 mg/mL which was very close to that of Vc (0.076 ± 0.004 mg/mL). The Tahe samples had good antioxidant activity. Principal component activity analysis indicated that the Tahe samples of P. incarnata had the highest potential antioxidant properties, and may be a valuable antioxidant natural resource in the northeast of China.