Chemical characterization of Opuntia dillenii and Opuntia ficus indica fruits

The chemical compositions (moisture, °Brix, total fibre, protein, fat, ash, pH, acidity, ascorbic acid, total phenolics, Na, K, Ca, Mg, Fe, Cu, Zn, Mn, Ni and Cr) were determined in fruits belonging to two species of prickly pear, Opuntia ficus indica and Opuntia dillenii, from Tenerife Island. The chemical compositions of the two species were clearly different. However, no important differences were observed between orange and green prickly pears within the specie O. ficus indica. An important contribution to the intakes of fibre, ascorbic acid, Mn, Cr and total phenolics is provided by the consumption of prickly pears, particularly from fruits of O. dillenii. Applying factor and/or discriminant analysis, the prickly pear samples were differentiated according to the species, altitude and region of cultivation in the island.     

Effects of trace element supplementation on milk yield and composition in camels

Objective of the study was to determine milk yield and quality (fat, protein, mineral content) of camels reared in north-east Africa, supplemented with trace elements for the first nine months of lactation. Twelve multiparous lactating camels were divided into two groups: control and treated (trace element supplemented). Addition of trace elements did not affect milk production and milk fat and protein content (respectively 3.09 vs. 3.51 kg d⁻¹; 2.86 vs. 2.56%; 3.31 vs. 3.19%, treatment vs. control). Calcium and zinc contents of milk were significantly higher in treated animals (1.20 vs. 0.94 g L⁻¹ and 3.16 vs. 2.52 mg L⁻¹; P<0.01). Mineral status of lactating camels and of their calves was assessed by analysis of plasma. Camel control diet was deficient in copper and supplementation did not allow reaching, neither in milk nor in plasma, the threshold values. Results suggest that oral trace element supplementation could increase zinc excretion in camels’ milk, despite the low levels of zinc in plasma.     

Mineral and trace element content of various vegetarian foodstuffs available in Belgium

 Atomic absorption spectrometry was used to determine mineral (Na, K, Ca and Mg) and trace element content (Zn, Fe, Cu and Si) of various vegetarian foodstuffs in Belgium. Thirty-five commercially available products were analysed after a wet-acid destruction in a closed-vessel destruction bomb. Various important sources of the minerals and trace elements were identified. Since data for vegetarian foods in Belgium are non-existent, the concentration values are compared with the scarce literature data and particularly with levels found in the same products available in The Netherlands. Received: 2 June 1998 / Revised version: 5 October 1998     

基于微量元素多元统计和微观形态分析的花椒叶产地及品种判别

目的 采用微量元素多元统计和微观形态分析相结合的手段,从元素含量分布和形态结构的角度鉴别不同产地、品种的花椒叶,为市面上花椒叶混售、以次充好的现象提供解决思路。方法 采用湿法消解结合电感耦合等离子体发射光谱技术同步检测不同产地、品种12个样品中的Ba、Ce、Ho、La、Tm、Mo、Pr、Sr、P、Mg10种微量元素。利用主成分分析与聚类分析对数据进行研究,并基于扫描电子显微镜(scanning electron microscope, SEM)的微观形态分析佐证了多元统计分析的结论 。结果 主成分分析结果 显示, 2个主成分贡献率达到68.05%,样品可显著聚类为2类,扫描电镜下伏椒叶与油椒叶结构差异显著。部分元素的数值特征可将不同产地的伏椒叶和油椒叶进行区分。结论 本研究能够有效地判别不同产地、品种的花椒叶,可以为相关问题解决提供思路。     

Comparison of mineral and trace element contents in onion cultivars (Allium cepa L.)

BACKGROUND: P, Na, K, Ca, Mg, Fe, Cu, Zn, Mn and Se were determined in five traditional onion cultivars (Allium cepa L.) from Tenerife (Guayonje, San Juan de la Rambla, Carrizal Alto, Carrizal Bajo and Masca) and a commercial cultivar (Texas Early Grano 502) grown under the same agronomic, soil and climatic conditions in order to find out differences between these cultivars. RESULTS: Carrizal Alto presented the highest K content and lowest P, Na, Fe, Zn, Mn and Se. Texas cultivar had the highest P, Mg and Se contents, and the lowest contents of Ca, Cu and Mn. There were clear differences in the mineral and trace elements contents between the two seed origins of San Juan de la Rambla cultivar. Many correlations were found between the parameters analyzed, emphasizing the Fe? Zn and Ca? Mn correlations. CONCLUSION: There were differences in the mineral and trace element composition between the onion cultivars. The environment and agronomic practices could affect the genetic information of the seeds, determining changes in the mineral and trace element composition. Linear discriminant analysis is a useful tool for differentiating onion samples according to cultivar and seed origin. Copyright © 2008 Society of Chemical Industry     

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.     

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.     

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.     

氨基酸微量元素螯合物替代无机微量元素对肉鸡饲养效果的影响

研究氨基酸微量元素螯合物替代饲粮中无机微量元素对肉鸡生产性能、饲粮养分代谢率和粪中微量元素含量的影响。1组为对照组饲喂基础饲粮,其Fe、Cu、Mn、Zn分别由硫酸亚铁、硫酸铜、硫酸锰和氧化锌提供,添加水平分别为Fe 100 mg/kg、Cu 20 mg/kg、Mn 120 mg/kg和Zn 120 mg/kg;2、3、4和5组分别用12.5%、25.0%、37.5%和50.0%的蛋氨酸螯合铁、铜、锰、锌替代基础饲粮各相应无机微量元素的25%、50%、75%和100%。63 d的试验结果表明:与对照组比较,用不同水平蛋氨酸螯合物(铁、铜、锌、锰)替代相应无机盐可一定程度提高肉鸡的生产性能,改善饲粮养分利用率,提高养殖效益,降低粪中微量元素的排泄量,尤以37.5%的蛋氨酸微量元素螯合物替代饲粮中75%的相应无机微量元素的效果良好。     

Verifying the geographical origin of beef: The application of multi-element isotope and trace element analysis

Beef samples originating from the major cattle producing regions of the world (Europe, USA, South America, Australia and New Zealand) have been analysed using IRMS and ICP-MS. C and N isotope composition of the beef defatted dry mass and H and O isotope composition of the corresponding lipid fractions were determined. It was observed that intensive maize and/or C₄ pasture feeding, during cattle production, gave rise to significant differences in the ¹³C content of beef produced in Brazil and the USA versus British beef fed predominantly on C₃ pasture and fodder. The mean δ²H‰ and δ¹⁸O‰ values of beef lipid correlated well with the latitude of production regions and the relationship between the H and O isotopic contents were found to parallel the Meteoric Water Line. These findings support the hypothesis that the systematic global variations in the ²H and ¹⁸O content of precipitation are transferred through drinking water and feed into beef lipid. Multi-element concentrations determined in the beef were combined with the stable isotope data and submitted to multivariate analysis. Six key variables (δ¹³C‰ (defatted dry mass), Sr, Fe, δ²H‰ (lipid), Rb and Se) were identified by canonical discriminant analysis as providing the maximum discrimination between beef samples on the basis of the broad geographical areas (Europe, South America and Australasia). It was concluded that the methodology in its current state can be used to provide reliable origin information, but this is dependent upon the countries under investigation.     

Differentiation of potato cultivars experimentally cultivated based on their chemical composition and by applying linear discriminant analysis

Moisture, starch, amylose, fibre, proteins, ascorbic acid, total phenol compounds, acidity, pH, ash and mineral and trace elements were determined in 10 potato cultivars from Canary Islands experimentally cultivated. Six of the cultivars were also cultivated in two locations, to ascertain the impact of different soil types on the parameters measured. There were differences between cultivars in both, physicochemical parameters and mineral and trace elements analysed. There were significant differences in the mean values obtained for all the parameters considered, except for ascorbic acid, between both locations. Application of linear discriminant analysis allowed to classify the potato samples according to the cultivar, and according to growing location.     

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.     

Investigation by ICP-MS of trace element levels in vegetable edible oils produced in Spain

The content of trace elements (Ag, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Ti, Tl and V) in edible oils (virgin olive, olive, pomace-olive, sunflower, soybean and corn) from Spain was determined, using inductively-coupled plasma-mass spectrometry (ICP-MS) after microwave digestion, employing only nitric acid in this step. The method has been validated by using both an oil reference material and recovery experiments over different oil samples, obtaining satisfactory results in all cases. Inter-day repeatabilities lower than 10% were observed for all of the analysed elements in the different kinds of oil samples. Studying the content of trace elements, in order to detect tendencies in the samples of the same type of oil, principal components analysis was used. Promising groupings were observed using a model with two principal components and retaining 75.3% of the variance.     

Mineral and trace element concentrations of dairy products from goats’ milk produced in Tenerife (Canary Islands)

The concentrations of the minerals, Na, K, Ca and Mg, and the trace elements, Fe, Cu, Zn and Se, were determined in 400 samples of goats’ dairy products (100 raw milk, 100 whey, 100 fresh and 100 semi-hard cheeses) produced in the island of Tenerife. All the minerals and trace elements analysed presented significant differences in the concentration between the dairy products analysed. The season of production had a greater influence on the mineral and trace element concentration than the region of production and the amount of fibre in the goats’ diet. An almost complete differentiation of the samples according to the type of dairy product was observed applying a stepwise discriminant analysis.     

Gross composition,amino acid,phytic acid and trace element contents of thirteen cowpea cultivars and their nutritional significance

Thirteen cultivars of cowpea (Vigna unguiculata (L) Walp) were analysed for their proximate composition, amino acid, trace element and phytic acid contents. Crude protein values ranged from 206·8 to 283·8 g kg^?1 DM. The mean contents (g kg^?1) of other major nutrients were ether extract, 18·6; ash, 38·8; total dietary fibre, 121·8 and carbohydrates, 573·4. When compared with the provisional amino acid scoring pattern of FAO, all cultivars were low in methionine and high in lysine, isoleucine, leucine and phenylalanine plus tyrosine. Values for threonine and valine were variable compared with the pattern. The range of values for the chemical score was 0·61–0·74. Phytic acid values ranged from 5·10 to 10·27 g kg^?1, and the phytate: zinc molar ratios were all higher than that (15:1) above which zinc deficiency can be induced. Most of the trace elements showed wide variation in their occurrence among the cultivars. The values for zinc and iron showed less variation. The toxic elements mercury and selenium were present in varying amounts in more than half of the cultivars while tin was found in only one variety.     

中药渣袋栽平菇中微量元素的分析

对中药渣袋栽平菇中微量元素进行研究,用湿法消解样品,原子吸收分光光度法进行微量元素的测定.结果表明:该方法灵敏度高,检出限低,精密度、准确度好;药渣袋栽平菇中微量元素Cu、Zn、Fe、Mn平均含量分别为:9.199mg/kg、113.9mg/kg、102.9mg/kg、8.095mg/kg,与对照组比较无明显差别.     

野生玫瑰果肉氨基酸和微量元素分析与评价

采用氨基酸自动分析仪和电感耦合等离子质谱仪分析比较了不同采收期野生玫瑰A、B两个品系果肉中氨基酸和微量元素的含量及其变化趋势。结果表明,A、B两个品系果肉中氨基酸、必需氨基酸及药用氨基酸含量较高,种类较丰富,属于优质蛋白;A品系氨基酸的种类数量和含量高于B,B品系氨基酸质量好于A;A、B两个品系氨基酸含量均在8月中旬左右达到最高,且总体呈不稳定、动态的变化过程,A随着果实成熟呈总体上升,B先升高后下降。A品系果肉中微量元素种类较B丰富,A和B同种微量元素含量比较,A高于或远远高于B;随着果实逐渐成熟A和B微量元素总体呈下降趋势。      

Impact of trace element addition on degradation efficiency of volatile fatty acids, oleic acid and phenyl acetate and on microbial populations in a biogas digester

The effect of trace element addition on anaerobic digestion of food industry- and household waste was studied using two semi-continuous lab-scale reactors, one (R30+) was supplied with Fe, Co and Ni, while the other (R30) acted as a control. Tracer analysis illustrated that methane production from acetate proceeded through syntrophic acetate oxidation (SAO) in both digesters. The effect of the trace elements was also evaluated in batch assays to determine the capacity of the microorganisms of the two digesters to degrade acetate, phenyl acetate, oleic acid or propionate, butyrate and valerate provided as a cocktail. The trace elements addition improved the performance of the process giving higher methane yields during start-up and early operation and lower levels of mainly acetate and propionate in the R30+ reactor. The batch assay showed that material from R30+ gave effects on methane production from all substrates tested. Phenyl acetate was observed to inhibit methane formation in the R30 but not in the R30+ assay. A real-time PCR analysis targeting methanogens on the order level as well as three SAO bacteria showed an increase in Methanosarcinales in the R30+ reactor over time, even though SAO continuously was the dominating pathway for methane production. Possibly, this increase explains the low VFA-levels and higher degradation rates observed in the R30+ batch incubations. These results show that the added trace elements affected the ability of the microflora to degrade VFAs as well as oleic acid and phenyl acetate in a community, where acetate utilization is dominated by SAO.     

Non-essential and essential trace element concentrations in meat from cattle reared under organic,intensive or conventional production systems

We evaluated if differences in non-essential and essential trace element accumulation in beef-cattle reared under different systems (including organic, conventional and intensive management) were reflected in the meat derived from these animals. Diaphragm muscle from 166 calves from nine farms were analysed. Muscle cadmium concentrations were low (<10 µg/kg wet weight) and muscle arsenic, mercury and lead levels were below the limits of detection (<12, 2 and 3 µg/kg, respectively) in most (77–97%) samples; there were no significant differences between farms. Essential trace element concentrations in muscle were generally within adequate physiological ranges and, although they varied significantly between farms, this was not apparently related to management practices. There were no significant correlations in element concentrations between muscle and liver or kidney (organ concentrations that better reflect exposure), except for cobalt (positive association) and zinc (negative association). Non-essential and essential trace element concentrations in muscle in the studied animals did not generally reflect differences in exposure. This is particularly relevant for animals reared in systems (such as organic farms) where cattle are exposed to higher levels of non-essential elements (probably due to soil ingestion when grazing) but also can suffer from mineral deficiencies.     

Chemometric evaluation of trace metal concentrations in some nuts and seeds

Seventeen trace metals in acid digests of nuts and seeds were determined using inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. The data were subjected to chemometric evaluation using principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) in an attempt to classify the samples. Hazelnuts (raw and dry roasted), almonds (raw and dry roasted), sunflower seeds (black and white), peanuts (raw and dry roasted), cashew nuts, Brazil nuts, walnuts, chickpeas (raw and dry roasted), pumpkin seeds (raw and dry roasted), and pistachio nuts were used as samples. The samples were classified into seven groups by PCA and CA. All group members determined using PCA and CA were found by LDA to be correctly classified in the predicted groups. Interestingly, the chemometric evaluation indicated that the raw and roasted nuts are very close to each other even though some originated from different countries.