Levels of inorganic constituents in raw nuts and seeds on the Swedish market

Investigation of accumulation of element contents in some wild and cultivated dried fruits

In this study, the moisture and biogenic element quantities of most wild and cultivated edible dried fruits were investigated. Macroelements found in highest amounts in fruits were K, P, Ca, and Mg. While K quantities of the fruits are recorded between 5212.77 ("white myrtle") and 25550.60 mg/kg ("black nightshade"), P amounts of the fruits were characterized to be between 949.08 (black myrtle) and 4420.75 mg/kg ("black nightshade"). Ca and Mg amounts of the fruits were assessed to be between 359.83 (plum) and 4330.89 mg/kg ("yellow hawthorn") to 214.98 (plum) and 1852.04 mg/kg ("black nightshade"), respectively. Fe and B quantities of the fruitss were established to be between 2.69 ("black myrtle") and 60.13 mg/kg (cherry) to 3.76 ("black myrtle") and 76.25 mg/kg (sour cherry), respectively. In general, except for white and black myrtle fruits, it is thought that other fruits can be good sources of P, K, and Fe. P contents of "laurel cherry," "cherry," "black nightshade," and "Fragrant black grapes" were found partly high than those of other fruits. "Cherry laurel," "sour cherry," "cherry," "pear," "black nightshade," "black fig," and "hawthorn (yellow)" fruits contain more K than other fruits.

Multi-Element Assessment of Potentially Toxic and Essential Elements in New and Traditional Food Varieties in Sweden

With the global movement toward the consumption of a more sustainable diet that includes a higher proportion of plant-based foods, it is important to determine how such a change could alter the intake of cadmium and other elements, both essential and toxic. In this study, we report on the levels of a wide range of elements in foodstuffs that are both traditional and "new" to the Swedish market. The data were obtained using analytical methods providing very low detection limits and include market basket data for different food groups to provide the general levels in foods consumed in Sweden and to facilitate comparisons among traditional and "new" food items. This dataset could be used to estimate changes in nutritional intake as well as exposure associated with a change in diet. The concentrations of known toxic and essential elements are provided for all the food matrices studied. Moreover, the concentrations of less routinely analyzed elements are available in some matrices. Depending on the food variety, the dataset includes the concentrations of inorganic arsenic and up to 74 elements (Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, K, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Te, Th, Ti, Tl, U, W, V, Y, Zn, Zr, rare Earth elements (REEs) (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, and Yb), platinum group elements (PGEs) (Ir, Os, Pd, Pr, Pt, Re, Rh, Ru, and Pr), and halogens (Br, Cl, and I)). The main focus (and thus the most detailed information on variation within a given food group) is on foods that are currently the largest contributors to dietary cadmium exposure in Sweden, such as pasta, rice, potato products, and different sorts of bread. Additionally, elemental concentrations in selected food varieties regarded as relatively new or "novel" to the Swedish market are provided, including teff flour, chia seeds, algae products, and gluten-free products.

Determination of 48 elements in 7 plant CRMs by ICP-MS/MS with a focus on technology-critical elements

Seven plant certified reference materials (NIST SRM1515 Apple Leaves, NIST SRM1547 Peach Leaves, BCR-129 Hay Powder, BCR-670 Aquatic Plant, GBW07603 Bush Twigs and Leaves, GBW10015 Spinach Leaves and NCS ZC73036a Green Tea) were analysed for their mass fractions of 48 elements by inductively coupled plasma tandem-mass spectrometry (ICP-MS/MS): Li, Be, Na, Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Nb, Mo, Ag, Cd, Sb, Te, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ta, Tl, Pb, Bi, Th, U. Special focus was put on the determination of technology-critical elements (TCEs), to which, e.g. Li, Be, Ga, Ge, Nb, Sb, Ta, Tl, Bi, and the rare-earth elements (REEs, lanthanides and Y) are counted. Closed-vessel microwave digestion was performed using HNO₃, H₂O₂ and HBF₄. The average bias for certified values is  - 1% ± 13% (SD). Limits of detection (x_L) in the measured solutions lie between 13 fg g^-1 (Tb) and 52 ng g^-1 (Ca). This article seeks to provide an optimised measurement procedure for the determination of element mass fractions of emerging importance in environmental samples, which are challenging to analyse with more traditional techniques such as single-quad ICP-MS. In addition, it aims to improve the characterisation of commonly used plant reference materials by providing mass fraction data for rarely studied elements.

Assessment of the Safe Consumption of Nuts in Terms of the Content of Toxic Elements with Chemometric Analysis

Nuts are characterized by high nutritional value and are recommended as a part of a healthy diet. At the same time, toxic elements could also be found in them. In this research, we measured the content of As, Cd, Pb and Hg in a wide variety of edible nuts. To determine the As content, inductively coupled plasma mass spectrometry (ICP-MS) was applied. Cd and Pb were detected by the electrothermal atomic absorption spectrometry analytical technique (ETAAS) with Zeeman background correction, while atomic absorption spectrometry method (AAS) with the amalgamation technique in the case of Hg was used. The study material consisted of 120 samples without replications (10 for each subgroup) including the following nuts: Almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, peanuts, pecan nuts, pine nuts, pistachios and walnuts. Indicators such as the target hazard quotient (THQ), cancer risk (CR) and hazard index (HI) were used to assess the health risk. The highest median As, Cd, Pb and Hg contents were observed for pistachios (192.42 µg/kg), pine nuts (238.40 µg/kg), peanuts (82.06 µg/kg) and pecans (82.06 µg/kg), respectively. The exceedance of the established limits was found in the case of Pb for nine samples: macadamia nuts (221.49 µg/kg; 2350.94 µg/kg; 2581.43 µg/kg), pine nuts (266.33 µg/kg), peanuts (1353.80 µg/kg) and pecans (2689.13 µg/kg, 2758.26 µg/kg, 2992.29 µg/kg and 3169.41 µg/kg). Extremely high (>2500 µg/kg) Pb content was found in 33% of studied pecans imported from the USA. The health risk indicators did not identify increased health risk. This research is significant considering the food safety issues and indicates the need to regularly control the content of toxic elements in food, as well as to establish the specific limits for heavy metals content in nuts. The chemometric analysis included cluster analysis and principal component analysis (PCA). Cluster analysis made it possible to distinguish four subgroups on the basis of the ability to accumulate toxic elements: pine nuts, pecans, pistachios and other analysed nuts. PCA indicated primarily factor 1, distinguishing mainly pecans, macadamia nuts and peanuts. Chemometric analysis can be a useful tool in estimating the ability of different nut species to accumulate contaminants.

Biogenic and Risk Elements in Walnuts (Juglans regia L.) from Chosen Localities of Slovakia

Walnuts (fruits Juglans regia, L.) belong among to the most spread, commercially grown tree nuts in the world. Nuts have grown higher attention in last years as valuable sources of essential elements; they are rich in non-essential fatty acids, proteins, fibre, plant sterols and minerals including potassium and magnesium and antioxidants. Determination of elements distribution in nuts is required not only for evaluation of total intake of essential elements in our food, but it is also useful for gaining data on contamination of foodstuffs by risk elements, but also for monitoring of heavy metal contamination in foodstuffs. Walnut samples were taken from three selected areas in Slovakia. The first location is in the vicinity of the cities Strážske, Humenné and Vranov nad Topľou, the second one is situated close to the city of Prievidza and the last one is close to the city of Vráble. The results of evaluation showed that the content of the elements monitored in location of Vráble did not exceed the limits set by the Regulation of Ministry of Health of Slovak Republic No 2/1994. In the half of samples taken from the location of Strážske, higher content of cadmium as the permitted limit has been found. The samples exceeded the amounts allowed by the Regulation No 2/1994 in contaminated area called "The dangerous triangle". Potential consumption of these walnuts could negatively affect human organism, but only if the kernels from the exact locality would be consumed in very high daily amounts (100-fold higher intake as daily intake according to the Statistical Office of SR).

Variability of Chemical Profile in Almonds (Prunus dulcis) of Different Cultivars and Origins

Almonds show a great variability in their chemical composition. This variability is a result of the existence of a diverse range of almond cultivars, the self-incompatibility of most almond cultivars, and the heterogeneous harvesting conditions found around the different locations where almons are grown. In the last years, the discrimination among almond cultivars has been the focal point of some research studies to avoid fraud in protected geographical indications in almond products and also for selecting the best cultivars for a specific food application or the most interesting ones from a nutritional point of view. In this work, a revision of the recent research works related to the chemical characterization and classification of almond cultivars from different geographical origins has been carried out. The content of macronutrients, tocopherols, phytosterols, polyphenols, minerals, amino acids, and volatile compounds together with DNA fingerprint have been reported as possible cultivar and origin markers. The analysis of the results showed that no individual almond compound could be considered a universal biomarker to find differences among different almond cultivars. Hence, an adequate selection of variables or the employment of metabolomics and the application of multivariate statistical techniques is necessary when classification studies are carried out to obtain valuable results. Meanwhile, DNA fingerprinting is the perfect tool for compared cultivars based on their genetic origin.

Simultaneous determination of Ba, Co, Fe, and Ni in nuts by high-resolution continuum source atomic absorption spectrometry after extraction induced by solid-oil-water emulsion breaking

This paper describes the simultaneous determination of Ba, Co, Fe, and Ni in nuts by high-resolution continuum source atomic absorption spectrometry after extraction induced by solid-oil-water emulsion breaking. Extraction yields ranged from 94.9 for Ba to 109.8% for Fe. Simultaneous measurements were carried out at secondary lines of Ba, Co, Fe, and Ni. The limits of detection and quantification were, respectively, 3.819 and 1.146 mg L^-1 for Ba, 2.274 and 7.421 µg L^-1 for Co, 0.095 and 0.285 mg L^-1 for Fe, and 2.138 and 6.614 µg L^-1 for Ni. The precision ranged from 3.1 to 4.2%, 1.5 to 8.0%, 1.6 to 6.6%, and 0.4 to 6.1% for Ba, Co, Fe and Ni, respectively. The method accuracy was assessed by recovery tests and comparison of the results obtained by the proposed extraction method with those obtained after acid digestion. Recoveries ranged from 93.5 for Ni to 104.5% for Co.

Origin Determination of Walnuts (Juglans regia L.) on a Worldwide and Regional Level by Inductively Coupled Plasma Mass Spectrometry and Chemometrics

To counteract food fraud, this study aimed at the differentiation of walnuts on a global and regional level using an isotopolomics approach. Thus, the multi-elemental profiles of 237 walnut samples from ten countries and three years of harvest were analyzed with inductively coupled plasma mass spectrometry (ICP-MS), and the resulting element profiles were evaluated with chemometrics. Using support vector machine (SVM) for classification, validated by stratified nested cross validation, a prediction accuracy of 73% could be achieved. Leave-one-out cross validation was also applied for comparison and led to less satisfactory results because of the higher variations in sensitivity for distinct classes. Prediction was still possible using only elemental ratios instead of the absolute element concentrations; consequently, a drying step is not mandatory. In addition, the isotopolomics approach provided the classification of walnut samples on a regional level in France, Germany, and Italy, with accuracies of 91%, 77%, and 94%, respectively. The ratio of the model's accuracy to a random sample distribution was calculated, providing a new parameter with which to evaluate and compare the performance of classification models. The walnut cultivar and harvest year had no observable influence on the origin differentiation. Our results show the high potential of element profiling for the origin authentication of walnuts.

Quality Characteristics and Volatile Profile of Macarons Modified with Walnut Oilcake By-product

Walnut oilcake is a low-cost by-product of the edible oil industry but at the same time it is a valuable source of dietary fiber, natural antioxidants, and polyunsaturated fatty acids. In the context of health-friendly confectionary food products and to reduce the production cost, the aim of this study was to investigate the effect of walnut oilcake by-product on the quality characteristics and volatile profile of modified macarons. For this purpose, GC-MS and ITEX/GC-MS techniques were used to obtain the fatty acids methyl esters and the volatile profiles; physicochemical analyzes were performed to determine the nutritional characteristics and a nine-point hedonic scale test was performed for the sensory characteristics. The substitution of almond flour with 0%, 10%, 25% and 50% walnut oilcake powder increased the fiber, total phenolic content, and antioxidant capacity. Hedonic scores of the macaron samples made with different percentage of walnut oilcake decreased to additions of over 10%. Moreover, this result is emphasized by Pearson's correlation parameters indicating as optimal addition for modified macarons, percentages up to 10% of walnut oilcake. This approach could reduce the costs related to the acquisition of the ingredients due to the oilcake price which is 3% of the almonds flour price.

Alves R, Santos J, S. Pinho R, I. Silva S, Delerue-Matos C, P. P. Oliveira MB. Oilseeds from A Brazilian Semi-Arid Region: Edible Potential Regarding the Mineral Composition

Oilseeds from five native plant species with edible potential from the Brazilian Caatinga semi-arid region (Diplopterys pubipetala, Barnebya harleyi, Croton adamantinus, Hippocratea volubilis, and Couroupita guianensis) were investigated regarding their mineral contents. The minerals, Na, K, Ca, Mg, Fe, Cu, Cr, Al, were analyzed by high-resolution continuum source atomic absorption spectrometry (HR–CS AAS) and P by the vanadomolybdophosphoric acid colorimetric method. K, Mg, and P were the main elements found (1.62–3.7 mg/g, 362–586 µg/g, and 224–499 µg/g dry weight (dw), respectively). B. harley seeds contained the highest amounts of K and P, while C. guianensis seeds were the richest in Mg. Fe was the most abundant oligoelement (2.3–25.6 µg/g dw). Cr contents were below the limit of quantification for all samples and Al amounts were low: 0.04–1.80 µg/g dw. A linear discriminant analysis clearly differentiated B. harleyi and C. guianensis samples from the remaining ones. In sum, these oilseeds from the Brazilian Caatinga semi-arid region seem to have the potential to be used as natural sources of minerals, mainly K.

The Inorganic Component as a Possible Marker for Quality and for Authentication of the Hazelnut's Origin

The inorganic component of hazelnuts was considered as a possible marker for geographical allocation and for the assessment of technological impact on their quality. The analyzed samples were Italian hazelnuts of the cultivar Tonda Gentile Romana and Turkish hazelnuts of the cultivars Tombul, Palaz and Çakildak. The hazelnuts were subjected to different drying procedures and different conservative methods. The concentration of 13 elements, namely Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, P, Sn, Sr and Zn, were quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES). All the samples were previously digested in a microwave oven. Before proceeding with the analysis of the samples, the whole procedure was optimized and tested on a certified reference material. The results show that the inorganic component: (i) can represent a fingerprint, able to identify the geographical origin of hazelnuts, becoming an important quality marker for consumer protection; (ii) is strongly influenced by the treatments undergone by the investigated product during all the processing stages. A pilot study was also carried out on hazelnuts of the cultivar Tonda Gentile Trilobata Piemontese, directly harvested from the plant during early development to maturity and analyzed to monitor the element concentration over time.

Inorganic arsenic in food products on the Swedish market and a risk-based intake assessment

Inorganic arsenic (iAs) and total arsenic (tAs) were determined in common food from the Swedish market. Special focus was on rice, fish and shellfish products. For the speciation of iAs the European standard EN:16802 based on anion exchange chromatography coupled to ICP-MS was used. The two market basket food groups cereals (including rice), and sweets and condiments (a mixed group of sugar, sweets, tomato ketchup and dressings), contained the highest iAs levels (means 9 and 7 μg iAs/kg), whereas other food groups, including fish, did not exceed 2 μg iAs/kg. Varying levels of iAs were found in separate samples of tomato ketchup, 2.4-26 μg/kg, and is suggested to be one reason of the rather high average level of iAs in the food group sweets and condiments. Some specific food products revealed iAs levels much higher, i.e. rice crackers 152 and Norway lobster 89 μg iAs/kg. The intake of iAs via food was estimated by data from two national consumption surveys, performed in 2010-11 (1797 adults) and 2003 (2259 children). The estimated median iAs intakes in adults and children were 0.047 and 0.095 μg/kg body weight and day, respectively. The iAs intake for rice eaters was about 1.4 times higher than for non-rice eaters. Validation of the consumption survey-based iAs intake, using food purchase and market basket data mainly from 2015, resulted in a per capita intake of a similar magnitude, i.e. 0.056 μg/kg body weight and day. The estimated cancer risk for adults using low-dose linear extrapolation is <1 per 100,000 per year.

Elemental composition and nutritional value of Araucaria angustifolia seeds from subtropical Brazil

Consumed by populations in South America, Araucaria angustifolia seeds have received little study regarding elemental composition and nutritional value. Thirty-five seed sites from subtropical Brazil were sampled and seed concentrations of C, N, K, Ca, Mg, P, Fe, Zn, Mn, Cu, Mo, Ni, Co, Cr, Ba, and Cd were determined. The highest concentration of N was observed in samples from regions with Cfa climate (humid subtropical, oceanic climate, without dry season with hot summer) and igneous rock, which was superior to regions with Cfb climate (humid subtropical, oceanic climate, without dry season with temperate summer) and metamorphic rock. Seeds can be a source of nutrients: K (11.8 g kg-1), P (4.1 g kg-1), Mn (9.1 mg kg-1), Cu (7.2 mg kg-1), Mo (0.93 mg kg-1), and Cr (0.65 mg kg-1). Values for Ba (0.93 mg kg-1) and Cd (0.19 mg kg-1) indicated no risk to human health. This study expands knowledge regarding the elemental composition of A. angustifolia. Results indicate that these seeds have nutritional value, and their consumption can be a good strategy to improve overall human nutrition in this region of South America.

An apple a day? Assessing gardeners' lead exposure in urban agriculture sites to improve the derivation of soil assessment criteria

Globally, many of our urban agriculture sites (UAS) contain high levels of lead (Pb), a contaminant of toxicological concern to humans. To improve the derivation of soil assessment criteria at UAS, and avoid inappropriate closure of these valuable community spaces, we sampled nearly 280 paired soil and crop samples across 31 UAS gardens. This sampling was coupled with an exposure and food frequency questionnaire and participants blood Pb levels (BLL), (43 gardeners and 29 non-gardening neighbours). In 98% of the sampled soils, Pb concentrations were above the current UK soil guideline for UAS (80 mg/kg), however despite the high soil Pb (geometric mean: 324 mg/kg), and high soil bioaccessible Pb (geometric mean: 58.7%), all participants BLL were <4.1 μg/dL (range: 0.6-4.1 μg/dL). Indeed, there was no statistically significant difference between the BLL of the UAS gardeners and those of their non-gardening neighbours (p = 0.569). Pb uptake, however, varied with crop type and our study highlights the suitability of certain crops for growing at UAS with elevated Pb (e.g. tubers, shrub and tree fruit), whilst limiting the consumption of others (selected root vegetables, such as rhubarb, beetroot, parsnips and carrots, with observed Pb concentrations > 0.1 mg/kg FW). The importance of defining the exposure scenario of a specific sub-population (i.e. UAS gardeners) is highlighted. Our preferred models predict site specific assessment criteria (SSAC) of 722-1634 mg/kg. We found fruit and vegetable consumption rates by all participants, and not just the UAS gardeners, to be considerably higher than those currently used to derive the UK's category 4 screening levels (C4SLs). Furthermore, the soil to plant concentration factors (SPCFs) used to derive the UAS C4SL significantly over predict Pb uptake. Our study indicates it may be appropriate to develop a distinct exposure dataset for UAS. In particular we recommend the derivation of SPCFs that are reflective of urban soils, both in terms of the range of soil Pb concentrations typically observed, but also the sources (and hence human oral bioaccessibility and plant-availability) of this Pb.

Mineral Composition of Elements in Walnuts and Walnut Oils

Walnuts (Juglans nigra) are considered to be a functional food. In the present study, twenty one macro-, micro-, and trace elements (Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Se, Sr, and Zn) were selected to be determined in walnuts and walnut oils. The beneficial content of essential elements could be shown by the obtained results, the macro-elements Ca, K, Mg, and Na being present in nuts with 1062 mg/kg, 2771 mg/kg, 1426 mg/kg, and 42.3 mg/kg, respectively. Regarding micro- and trace elements, the following order (decreasing content) was found: Mn > Fe > Zn > B, Mo > Cu > Ni > Co > Al > Sr > Ba > Li > Pb > Se > Cr > As > Cd. Furthermore, the potentially toxic trace elements (As, Cd, Pb) determined were below the maximum allowed values in most of the investigated walnut samples. A comparison of oils and nuts revealed that the former contain lower concentrations of all elements analyzed except for Fe and Zn. This suggested the origin from contamination during oil processing. Fe influences the oil oxidation rate, thus its entry during production should be avoided.

Distribution, relationship, and risk assessment of toxic heavy metals in walnuts and growth soil

Walnut is one of the most popular nuts worldwide and contains various mineral nutrients. Little is known, however, about the relationship between toxic heavy metals in walnuts and growth soil. In this study, we investigated the distribution, relationship, and risk assessment of five toxic heavy metals-lead (Pb), arsenic (As), chromium (Cr), cadmium (Cd), and mercury (Hg)-in walnuts and growth soil in the main production areas of China. The results showed that the main heavy metal pollution in walnut and soil was Pb and Cd. Regionally, positive relationships existed between heavy metals and the pH and organic matter of soil. In addition, we observed a notable uptake effect between walnut and growth soil. In this study, we found a significant correlation (r = 0.786, P < 0.05) between the bioconcentration factors and the longitude of the sampling areas. The risks (total hazard quotients) of five heavy metals toward children and adults by dietary walnut consumption were 46.8 and 56.2%, respectively. The ability to identify toxic heavy metal pollution in walnuts and growth soil could be helpful to screen suitable planting sites to prevent and control heavy metal pollution and improve the quality and safety of walnut.

Hair Zinc: an Index for Zinc Status in Under-Five Children from Low-Income Communities in Kanam Area of North-Central Nigeria

Nutritional deficiencies of trace elements are among the top ten causes of death in Sub Saharan Africa. In Kanam Local Government Area of Nigeria, the problem is compounded by high levels of poverty and illiteracy. Abnormally low hair zinc levels are important, sensitive diagnostic biochemical indices of Zinc deficiency. The purpose of this study is to assess the zinc status of children less than 5 years in Kanam local government area, north-central Nigeria, by measuring the zinc level in hair samples collected from 44 under-5 children across the area. A household survey was made to assess the pattern and frequency of consumption of zinc-rich foods which was done by means of questionnaire. Hair samples were analysed for zinc content by the inductively coupled plasma-mass spectrophotometry (ICP-MS). The data were analysed statistically using the Student's t test, z test, and Pearson correlation, while questionnaire-captured data were analysed by simple arithmetic. The results of the analyses showed that the average hair zinc level was 74.35 ± 48.05 μg/g. This was below the normal range of 130-140 μg/g, for children less than 5 years. Based on the results, 86.36% have hair zinc level below the lower limit of the normal range of 130 μg/g. Between the gender, boys have higher hair zinc content than girls. Data from the questionnaire showed that 53.45% of the population studied have poor/inadequate intake of zinc-rich foods of animal origin, a dietary behaviour reported to predispose to micronutrient deficiency, including zinc.

Application of double-focusing sector field ICP-MS for determination of ultratrace constituents in samples characterized by complex composition of the matrix

The performance of double focusing, sector field mass spectrometry (ICP-SFMS) for determination of analytes, including technology critical elements (TCE), at ultra-trace levels in environmental and clinical matrices was critically evaluated. Different configurations of the ICP-SFMS introduction system as well as various sample preparations, pre-concentration and matrix separation methods were employed and compared. Factors affecting detection capabilities and accuracy of data produced (instrumental sensitivity, contamination risks, purity of reagents, spectral interferences, matrix effects, analyte recovery and losses) were discussed. Optimized matrix-specific methods were applied to a range of reference and control materials (riverine, brackish and seawaters; whole blood, serum and urine) as well as tap water and snow samples collected in the area of Luleå city, northern Sweden; brackish and seawater from the Laptev Sea; venous blood samples with a special emphasis on determination of Au, Ag, Ir, Os, Pd, Pt, Re, Rh, Ru, Sb and Te. Even though these low abundant elements are relatively under-documented, the results produced were compared with published data, where available.

A review of the impact of processing on nutrient bioaccessibility and digestion of almonds

Almond kernels contain phytochemicals and nutrients that potentially have positive health benefits in relation to heart disease, diabetes and obesity. One important mechanism associated with these benefits is an imposed limit on bioaccessibility (release) of nutrients, such as lipids, from almond tissue during mastication and digestion. Recent studies have demonstrated the importance of food structure during the digestion of plant foods. In particular, in the almond kernel, depending on its structure and degree of processing, the amount of lipid released from the almond tissue matrix and the fatty acids produced from lipolysis has been found to vary substantially. This review aims at discussing the commercial methods of almond processing and the different almond forms produced for human consumption, mainly with respect to their impact on nutrient composition, digestion and metabolism.

Toxic and essential elements in five tree nuts from Hangzhou market, China

In this study, a total of 35 tree nut samples of walnut, pecan, pine seed, hickory nut and torreya were obtained from 5 farm product markets in Hangzhou, China, and investigated for essential (Cr, Mn, Fe, Mo, Cu, Zn, Se and Sr) and toxic (Al, As, Cd and Pb) elements by inductively coupled plasma-mass spectroscopy. Mean elemental concentrations of different tree nuts were in the following ranges: Cr 0.26-0.78 mg kg^-1, Mn 42.1-174 mg kg^-1, Fe 33.7-43.9 mg kg^-1, Mo 0.11-0.48 mg kg^-1, Cu 10.3-17.6 mg kg^-1, Zn 21.6-56.1 mg kg^-1, Se 0.015-0.051 mg kg^-1, Al 1.44-37.6 mg kg^-1, As 0.0062-0.047 mg kg^-1, Cd 0.016-0.18 mg kg^-1 and Pb 0.0069-0.029 mg kg^-1. The estimated provisional tolerable daily intake of Al, As, Cd and Pb was much lower than the provisional tolerable daily intake.

Heavy metals in jujubes and their potential health risks to the adult consumers in Xinjiang province, China

The concentrations of seven heavy metals (HMs) in jujube samples collected from Hetian region (HTR), Hami region (HMR), Erkesu region (ESR), Bayikuleng region (BLR), and Turpan region (TUR) were determined by inductively coupled mass spectrometry (ICP-MS). The accuracy and precision of the analytical method were confirmed by the certified reference material (GBW 07605). In general, the concentration of iron was higher than those of the other six metals in the investigated jujube samples. The Hazard Quotient (HQ) and Hazard Index (HI) were calculated to evaluate the noncarcinogenic health risk from individual metal and combined metals due to the dietary intakes via consumption of jujube. Both HQ and HI levels were far below 1, suggesting no noncarcinogenic risks for Xinjiang adults under the current consumption rates of the jujubes. Among the jujubes from five different regions, BLR jujube had the highest HQ and HI. Fe and As were the most concerning HMs in the investigated jujube samples due to their higher relative contributions to HIs.

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.

Orchards for edible cities: cadmium and lead content in nuts, berries, pome and stone fruits harvested within the inner city neighbourhoods in Berlin, Germany

Today's urban gardening focuses mainly on vegetable production and rarely includes fruit trees. Health effects of consuming urban crops are questioned due to high local pollution loads. Here, we determined cadmium and lead content in the edible parts of nuts, berries, pome, and stone fruits harvested from fruit trees and shrubs within inner city neighbourhoods of Berlin, Germany. We analysed how local settings at sampling sites shaped the trace metal content. We revealed significant differences in trace metal content depending on species, fruit type, local traffic, and parameters related to barriers between the sampling site and neighbouring roads. Higher overall traffic burden and proximity to roads increased whereas buildings or vegetation as barriers reduced trace metal content in the edible biomass. We demonstrate, that the consumption of non-vegetable fruits growing in inner city sites in Berlin does not pose a risk on human health as long as the fruits are thoroughly washed and it is provided that site pollutions and impacts are considered in garden concepts and guidelines.

Copper, zinc, and cadmium in various fractions of soil and fungi in a Swedish forest

Ectomycorrhizal fungi profoundly affect forest ecosystems through mediating nutrient uptake and maintaining forest food webs. The accumulation of metals in each transfer step from bulk soil to fungal sporocarps is not well known. The accumulation of three metals copper (Cu), zinc (Zn) and cadmium (Cd) in bulk soil, rhizosphere, soil-root interface, fungal mycelium and sporocarps of mycorrhizal fungi in a Swedish forest were compared. Concentrations of all three metals increased in the order: bulk soil < soil-root interface (or rhizosphere) < fungal mycelium < fungal sporocarps. The uptake of Cu, Zn and Cd during the entire transfer process in natural conditions between soil and sporocarps occurred against a concentration gradient. In fungal mycelium, the concentration of all three metals was about three times higher than in bulk soil, and the concentration in sporocarps was about two times higher than in mycelium. In terms of accumulation, fungi (mycelium and sporocarps) preferred Cd to Zn and Cu. Zinc concentration in sporocarps and to a lesser extent in mycelium depended on the concentration in soil, whereas, the uptake of Cu and Cd by both sporocarps and mycelium did not correlate with metal concentration in soil. Heavy metal accumulation within the fungal mycelium biomass in the top forest soil layer (0-5 cm) might account for ca. 5-9% of the total amount of Cu, 5-11% of Zn, and 16-32% of Cd. As the uptake of zinc and copper by fungi may be balanced, this implied similarities in the uptake mechanism.

Selected Metals in Various Fractions of Soil and Fungi in a Swedish Forest

The patterns of uptake and distribution of Co, Ni, Cu, Zn, Cd, and Pb in the soil-mycelium-sporocarps compartments in various transfer steps are presented. I attempted to find out whether there is a difference between the uptake of metals from soil to fungi (mycelium/soil ratio) and transport within fungal thalli (sporocarps/mycelium ratio). The concentration of Cu, Zn, and Cd increased in the order bulk soil < soil-root interface (or rhizosphere) < fungal mycelium < fungal sporocarps. The concentration of Co, Ni, and Pb decreased in the order bulk soil (or rhizosphere) < fungal mycelium < soil-root interface < fungal sporocarps. The uptake of Cu, Zn, and Cd during the entire transfer process in natural conditions between soil and sporocarps occurred against a concentration gradient. Mycorrhizal fungi (mycelium and sporocarps) only absorbed Co, Ni, and Pb but did not accumulate these elements in their thalli. Metal accumulation within fungal mycelium biomass in the top forest soil layer (0–5 cm) may account for about 5% of the total amount of Co, 4% Ni, 7% Cu, 8% Zn, 24% Cd, and 3% Pb.

Metal concentrations in the soils and native plants surrounding the old flotation tailings pond of the copper mining and smelting complex Bor (Serbia)

In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As.

Correlations between potassium, rubidium and cesium ((133)Cs and (137)Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ((133)Cs and (137)Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and (133)Cs mass concentrations with (137)Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg(-1) for K (mean ± SD, dwt), 0.40 ± 0.09 g kg(-1) for Rb, 8.7 ± 4.36 mg kg(-1) for (133)Cs and 63.7 ± 24.2 kBq kg(-1) for (137)Cs. The mass concentrations of (133)Cs correlated with (137)Cs activity concentrations (r = 0.61). There was correlation between both (133)Cs concentrations (r = 0.75) and (137)Cs activity concentrations (r = 0.44) and Rb, but the (137)Cs/(133)Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The (133)Cs mass concentrations, (137)Cs activity concentrations and (137)Cs/(133)Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, (133)Cs and (137)Cs in sporocarps of S. variegatus is similar to other fungal species.