Mineral composition in four varieties of avocado (Persea gratissima, L.) from the island of Tenerife

The contents of macroelements (Na, K, Ca, Mg, and P) and microelements (Fe, Cu, Zn, Mn, and B) of four varieties of avocado obtained and consumed in the island of Tenerife, Canary Islands, have been determined. The samples mineral contents of the different avocado varieties showed significant differences. Thus, the concentration levels of Ca, Mg, and Mn are higher in the Hass variety; those of K, Fe, and Zn, in the Orotava variety; those of Na and B in the Hass and Fuerte varieties; that of P in the Arona and Hass varieties; and that of Cu in the Arona and Fuerte varieties. The area of origin of Hass avocado also influences the mineral content of the samples: those from the north of Tenerife show higher contents of K, Ca, P, Fe, Cu, Zn, and B, and those from the south, of Na, Mg, and Mn.     

Mineral composition of the red and green pepper (<Emphasis Type="Italic">Capsicum annuum</Emphasis>) from Tenerife Island

The content of macroelements (Na, K, Ca, Mg and P) and microelements (Fe, Cu, Zn, Mn and B) in green and red pepper samples consumed on the island of Tenerife, Canary Islands, has been determined. Analysis has shown the influence of the ripening stage on the mineral content of the pepper. Red pepper presents higher K, Mg, P, Fe, Cu, Zn, Mn and B concentration levels than green pepper. There are differences between the values obtained in this study and the values shown in different food composition tables; our results are higher in Na, Ca and Mg, and lower in K and Fe.     

Mineral composition of the banana (Musa acuminata) from the island of Tenerife

The content of major (Na, K, Ca, Mg and P) and minor elements (Fe, Cu, Zn, Mn and B) in bananas consumed on the island of Tenerife, Canary Islands, has been determined. Significant differences were observed in the mineral contents of the banana samples, with higher K, Mg, P, Fe, Cu, Zn and B levels in the banana grown in north Tenerife and a higher Ca content in the banana originating in the south of the island. Differences between these mineral contents and the fruit reported in the literature have been established and a comparison has been carried out with diverse food composition tables. The banana is shown to contribute to the recommended daily requirements of K, Mg, Cu and B.     

Mineral and trace element concentrations in cultivars of tomatoes

The concentrations of minerals (P, Na, K, Ca and Mg) and trace elements (Fe, Cu, Zn and Mn) were determined in 167 tomato samples belonging to five cultivars (Dorothy, Boludo, Dunkan, Dominique and Thomas) produced on the island of Tenerife. The contribution to the intake of minerals and trace elements was in general low, with special emphasis on the contributions of K and Mg. The cultivar, cultivation method, period of sampling and region of production in the island influenced the concentrations of minerals and trace elements of the tomatoes. Trace elements seemed more influenced by the cultivar than the minerals, and the cultivation method affected mineral contents more than trace element contents. The period of sampling had an important influence on the mineral and trace elements. Many correlations were observed between the minerals and trace elements studied. Applying discriminant analysis, the tomato samples tended to be classified according to the cultivation method, period of sampling and region of cultivation.     

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.     

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     

Multi‐element characterisation of carob,fig and almond liqueurs by MP‐AES

Carob pod, fig and almond liqueurs are produced in various Mediterranean regions. This work reports the mineral content of these traditional beverages and evaluates the influence of the raw material. Twenty‐five fruit liqueurs from 16 producers were analysed. A simple open‐vessel sample mineralization by wet digestion using nitric acid–hydrogen peroxide (1:1) was used before spectrometric analysis. Nine essential elements (Cu, Ca, Mg, Na, K, Fe, Zn, Mn and P) and two non‐essentials (Cd and Pb) were quantified by microwave plasma–atomic emission spectrometry (MP‐AES). Carob liqueur presented the broader profile of minerals and was the only fruit liqueur containing iron (72.7% of samples), phosphorous, manganese and low levels of lead (in two of the 11 samples). Conversely, almond liqueurs contained the lowest mineral content with only five elements detected. Fruit liqueurs showed variability in mineral content even within the same liqueur, presumably as a consequence of the different manufacturing processes. Despite this variability, application of principal component analysis to essential mineral concentrations (K, Na, Ca, Mg, Mn, Fe and Zn) resulted in satisfactory classification (PC1 and PC2 accounting for 78.5% of the total variance) of the Portuguese liqueurs evaluated. Copyright © 2018 The Institute of Brewing & Distilling     

加工精度对大米矿物元素指纹信息影响研究

矿物元素指纹分析技术已逐渐被应用到农产品的产地溯源中,大米中的矿质元素指纹信息的稳定性不仅与环境(地域和年际)密切相关,还受品种和加工精度的影响。研究农产品矿物元素指纹信息在不同加工等级与不同品种间的稳定性,解析品种、加工精度及其交互作用对各元素含量变异的贡献率,筛选出受品种、加工精度影响较小的元素作为产地溯源的指纹信息。可为农产品产地矿物元素指纹溯源技术的应用提供理论参考。本研究以水稻作为模式生物,于2013年收获期在黑龙江同一地市的3个品种的水稻样品,加工成5个不同等级,利用电感耦合等离子体质谱仪(ICP-MS)测定不同等级大米中49种矿物元素的含量。对数据进行单因素方差分析、多因素方差分析。大米中元素Na、Mg、Al、K、Ca、Cr、Mn、Fe、Co、Cu、Zn、Rb、Sr和Ba含量与加工精度密切相关;元素Na、Mg、Al、K、Ca、Cr、Mn、Cu、Zn、Rb和Mo含量与品种密切相关;在今后产地溯源技术筛选溯源指标时应考虑这些元素。     

Trace elements and metals in farmed sea bass and gilthead bream from Tenerife Island, Spain

The aim of this study was to determine the levels of metals (Ca, K, Na, Mg) and trace metals (Ni, Fe, Cu, Mn, Zn, Pb, Cd) in two fish species (gilthead bream [Sparus aurata] and sea bass [Dicentrarchus labrax]) collected from fish farms located along the coast of Tenerife Island. Ca, K, Na, Mg, Fe, Cu, Zn, and Mn were measured by flame atomic absorption spectrometry, whereas Pb, Cd, and Ni were determined using graphite furnace atomic absorption spectrometry. Mean Fe, Cu, Mn, and Zn contents were 3.09, 0.59, 0.18, and 8.11 mg/kg (wet weight) in S. aurata and 3.20, 0.76, 0.24, and 10.11 mg/kg (wet weight) in D. labrax, respectively. In D. labrax, Ca, K, Na, and Mg levels were 1,955, 2,787, 699.7, and 279.2 mg/kg (wet weight), respectively; in S. aurata, they were 934.7, 3,515, 532.8, and 262.8 mg/kg (wet weight), respectively. The Pb level in S. aurata was 7.28 ± 3.64 μg/kg (wet weight) and, in D. labrax, 4.42 ± 1.56 μg/kg (wet weight). Mean Cd concentrations were 3.33 ± 3.93 and 1.36 ± 1.53 μg/kg (wet weight) for D. labrax and S. aurata, respectively. All Pb and Cd levels measured were well below the accepted European Commission limits, 300 and 50 μg/kg for lead and cadmium, respectively.     

Comparative study of the mineral composition of several varieties of potatoes (Solanum tuberosum L.) from different countries cultivated in Canary Islands (Spain)

Potatoes are a basic component of human diets worldwide being an excellent source of minerals linked the maintenance of health. Contents of calcium (Ca), magnesium (Mg), potassium (K), sodium (Na), cupper (Cu), iron (Fe), manganese (Mn), zinc (Zn), nickel (Ni) and chromium (Cr) in seventy‐four fresh potato samples from different varieties consumed in Tenerife Island (Canary Islands, Spain) were determined by flame atomic absorption spetrometry (FAAS). The mean concentrations were 60.1 mg kg^?1, 222 mg kg^?1, 5047 mg kg^?1, 125 mg kg^?1, 1.69 mg kg^?1, 8 mg kg^?1, 1.70 mg kg^?1, 3.88 mg kg^?1, 62.7 μg kg^?1 and 19.9 μg kg^?1 for Ca, Mg, K, Na, Cu, Fe, Mn, Zn, Ni and Cr, respectively. The varieties of local potatoes presented higher mineral contents than imported potatoes. Potassium presented the highest contents in all varieties of potatoes. Iron was the most abundant microelement. Local potatoes offer greater nutritional contributions to the recommended intakes than imported varieties. Within the macrominerals, the highest contribution to the intakes was observed for K, while Fe was the trace element with the largest contribution to the proposed intake.     

Characterization of various chestnut cultivars by means of chemometrics approach

Chestnuts like other foodstuffs may be characterized by their chemical composition. The chemical composition of ascorbic acid, total acidity, pH, starch, refraction index (°Brix), moisture, ashes, insoluble fibre, soluble fibre, total dietary fibre, total proteins, cations (Na, K, Ca, Fe, Cu, Zn, Mn, Mg) and phosphorous was determined in 19 local chestnut varieties from three areas of production in the island of Tenerife. Significant differences were found between the mean values of moisture, starch, total phenols contents, total soluble and non-soluble fibre, Ca, Cu, K, Mg and Zn, obtained according to the area of production. Distribution patterns of the samples were established for correlating the chemical composition of the chestnuts and varieties, using different chemometrics tools such as cluster analysis, principal component analysis, factor analysis and linear discriminant analysis (LDA). Initially, cluster analysis made it possible to establish a primary relationship between the variables. When applying stepwise LDA the chestnut samples were well classified within their area of production. Also, when the stepwise LDA was used on the chestnut samples from area of production 2, 100% of the chestnut samples were also correctly classified within their variety.     

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.     

百香果中矿物元素分析

采用高压密封硝化罐消解样品,应用ICP-AES 法测定百香果果汁、果皮、种仁中20 种矿物元素 (Na、K 、C a 、Mg、Z n 、F e 、S r 、Cu 、Co 、Mn、Ge 、S e 、S n 、B a 、A l 、P b 、Hg、As 、C r 、Cd) 的含量,设计正交试验方案,通过方差分析选择最佳的试验操作条件,其回收率在95.0%～104.0% 之间,相对标准偏差小于2.15%。实验结果表明：百香果果汁、果皮、种仁中均含有丰富的Na、K、Ca、Mg、Zn、Fe、Ge等对人体有益的矿物元素,而对人体有害的元素均未检出,营养价值高,极具开发价值。     

微波消解ICP-OES测定牛蒡茶中的矿质元素

采用HNO3/H2O2微波消解的制样方法,利用全谱直读电感耦合等离子原子发射光谱仪（ICP-OES）对牛蒡茶中的Al、As、Ba、Ca、Cd、Cr、Cu、Fe、K、Mg、Mn、Na、Ni、P、Pb、Sr、Ti、Zn等18种矿质元素进行了测定。结果表明,牛蒡茶中含有人体必需常量元素K、Na、Ca、Mg、P和人体必需微量元素Cu、Fe、Mn、Ni、Ti、Zn,以及人体非必需的微量元素Al、Ba、Sr,而有害元素As、Pb、Cr、Cd均未检出。并建立了一种牛蒡茶中矿质元素的分析测试方法,各元素的回收率均在93.7%¹07%,相对标准偏差在1.31%².31%,检出限低且满足各元素分析要求,此方法具有简捷、快速、准确的特点。      

MINERAL COMPOSITION OF MEDLAR (MESPILUS GERMANICA) FRUIT AT DIFFERENT STAGES OF MATURITY

Abstract The mineral composition of medlar fruit collected (June 15 - October 8) in Turkey at five stages of development was studied. In the fruit, 32 minerals were analyzed and 16 minerals (Al, Ba, Ca, Cu, Co, Fe, K, Li, Mg, Mn, Na, Ni, P, Sr, Ti and Zn) were present at detectable levels. The ripe medlar fruit was richest in potassium (7370 μg/g dry wt), calcium (1780 μg/g dry wt), phosphorus (1080 μg/g dry wt), magnesium (661 μg/g dry wt) and sodium (183 μg/g dry wt). During the fruit development, Al, Ba, Fe, Mn, P, Sr, and Zn were highest in August (unripe fruits) while the concentrations of K, Ca, Mg and Cu gradually decreased throughout development. The ripe medlar fruit is an important source of nutritionally needed minerals and trace elements, in particular Ca, Cu, Fe, K, Mg, Mn, Na and Zn, for human populations in southeastern Europe, Turkey and Iran.     

ICP-OES法分析测定大红袍花椒中的矿质元素

经湿法微波消解制样,利用全谱直读电感耦合等离子发射光谱法(ICP-OES)对大红袍花椒中的矿质元素进行全面详细的分析测定。测定结果表明,花椒中含有K、Ca、P、Mg、S、Al、Fe、Sr、Na、Mn、B、Zn、Ba、Cu、Ti、Cr等16种矿质元素,常量矿质元素中钾和钙的含量较高,微量元素中,铝、铁、锶、锰、硼含量丰富。分析方法回收率在90.1%～109.1%之间,测定结果相对标准偏差在0.55%～8.95%之间。该方法简单、快速、可靠、灵敏度高,且多元素可同时测定,能满足实际样品分析要求。分析结果可为花椒的相关研究提供参考。     

Mineral profile of “fino” wines using inductively coupled plasma optical emission spectrometry methods

Fifty wines from the Denomination of origin (DO) of Condado de Huelva were analysed for mineral content by measuring 12 elements (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn) using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Samples were previously digested by heating with H₂O₂/HNO₃ mixture. The results obtained showed that metal data set were non-normally distributed and accordingly, non-parametric statistics were applied. The average levels (medians) of these elements found in the samples are as follows, in mg/L: 2.54 (Al); 0.06 (Ba); 82.58 (Ca); 0.21 (Cu); 3.53 (Fe); 865.34 (K); 68.87 (Mg); 0.71 (Mn); 32.77 (Na); 71.61 (P); 0.48 (Sr); 0.56 (Zn). The interrelation of metal couples was studied through the Spearman non-parametric sample correlation, being Fe/Al, P/Mg, and Zn/Ba the most important correlations established. As a result of this study, we can suggest that the contribution to the safety intake limits (per week) of the studied elements through the wine consumption is not significant. Actually, they range between 0.1% in Fe and 11.9% in Mg, for normal drinkers.     

南瓜中矿物质元素分析及功能特性研究

采用火焰原子吸收法对成熟南瓜瓜肉和瓜仁中的主要矿物质元素K、Ca、Mg、Na、Zn、Fe、Cu、Cr、Mn、Co等10种元素的含量进行了测定。结果表明,南瓜中矿物质元素含量极其丰富,含有大量的K,且Zn、Cr、Mn等含量也较高。同时分析了元素的功能特性,以期对进一步开发新的南瓜保健产品起指导作用。     

Mineral composition of frozen green asparagus

The contents of macroelements (Ca, Mg, Na, K y P) and trace elements (Cu, Fe, Zn and Mn) of frozen green asparagus were determined by atomic absorption spectrometry to investigate the possible changes during 45 and 90 days frozen storage at –18 °C. A significant decrease of mineral concentrations was observed at 45 days of frozen storage. After 90 days, modifications were not observed, except for Cu and P concentrations. The asparagus thickness factor resulted in significant differences in the Cu, Fe, Zn, Ca and K contents. Frozen storage time involved smaller percentages of mineral retention in the <11 mm spear for Ni, Ca, Mg, K and P, and, for the rest of mineral elements, the frozen storage effect was similar for both thicknesses (<11 mm and >14 mm). The highest mineral concentration was found in the apical portion or tip of green asparagus, except for Mn, Cr and K. Mineral retention percentages after frozen storage time were similar in both portions (apical and basal) of the spear.     

Multivariate characterization of table olives according to their mineral nutrient composition

Different commercial presentations of table olives were characterized by their mineral compositions. Cu, Fe, Mn, Zn, Ca, Mg, Na, K, and P were determined. The processing of table olives affects the mineral content of commercial presentations and significant differences (p < 0.05) were found among green (Spanish style), directly brined, and ripe olives. A predictive discriminate analysis showed that the most discriminating elements were Fe, K, Na, Mn, Cu, and P (among styles) and with Ca (among cultivars). A good classification and cross-validation was observed in the case of elaboration styles but discrimination among cultivars was less conclusive. A further analysis of the confusion matrix, according to cultivars, showed that the lower classification efficiency, in this case, was mainly due to misclassification of samples from Manzanilla and Gordal cultivars. The analysis of the confusion matrix can be useful when the assessment of its results is not obvious.