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| 2. |
- Kollander, Barbro, et al.
(author)
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Application of a fast multi element screening method using ICP-AES on liver samples and mice organs
- 2011
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Other publication (other academic/artistic)abstract
- A fast mix and measure method for direct multi element analysis of non digested biological samples was used for the simultaneous determination of low, medium, and high concentrations elements in liver samples from domestic and wild animals. The method was also used for screening several elements in different organs from five mice. Brain (cerebrum, left and right cerebellum), heart, kidney, liver, lung, spleen, and blood samples were analysed. The total time for sample preparation and measurement is four minutes only for each sample (dissection not included). Quantitative results within ± 10 % are presented in the liver samples for Al, Cd, Pb, Mn, Sr, P, K, and semi quantitative within ± 20 % for Ca, Co, Cu, Fe, Mg, and Zn. The overall reproducibility was around 5 % for most elements, slightly higher for elements close to the detection limit, which meets well with the 2-3 % obtained for the acid digestion method used for comparison. A bovine liver sample was spiked with low amounts of Al, Cd, Co, and Pb to outline the possibilities of the slurry method to quantify concentrations close to the estimated limit of quantification. The recoveries were 103, 104, 97 and 103 % respectively.
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| 3. |
- Kollander, Barbro, et al.
(author)
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Fast multi-element screening of non-digested biological materials by slurry introduction to ICP-AES.
- 2010
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In: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 80:5, s. 2068-2075
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Journal article (peer-reviewed)abstract
- A fast method for direct multi-element analysis of non-digested biological samples is presented. The only sample preparation needed is 1 min homogenization with a Polytron mixer in a small volume of neutral phosphate buffer saline solution (PBS). The total time for analysis (sample preparation and measurement) is 4 min only. This "mix and measure" method can handle large sample loads of biological samples and thus minimize dilution of trace elements. For example 100% whole blood was introduced without any clogging of the introduction system or extinguishing of the plasma. In 70% (v/v) whole blood reference material 14 of 16 analytes were quantified within ±10% (Al, B, Ba, Ca, Cu, Fe, Mg, Mn, P, Pb, S, Sr, Ti and Zn) and two semi-quantified within ±20% (Cd and K). Fresh bovine liver was also analyzed with the same method and 7 of 9 analytes were quantified in 5% (w/v) liver slurry. Three different nebulizers were tested, Glass Expansion Concentric (GEC) of Meinhard type, Cross Flow and Burgener T2100 and they performed roughly equally well in giving quantitative results for the slurries but the sensitivity was better with the GEC. The stability of the plasma was studied by evaluating the ratio of Mg 280.270 nm and Mg 285.213 nm lines. When increasing the sample load from 20 to 100% (v/v) of whole blood and from 0.5 to 10% (w/v) of bovine liver the Mg ratio was constant within a few percent for all of the nebulizer tested. The ratio of the sensitivity between GEC and Burgener T2100 was studied and the ratio increased with the energy sum for atomic and ionic lines separately.
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| 4. |
- Kollander, Barbro
(author)
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Inductively Coupled Plasma Atomic Emission Spectrometry : Exploring the Limits of Different Sample Preparation Strategies
- 2011
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Doctoral thesis (other academic/artistic)abstract
- This thesis describes two different sample preparation strategies for inductively coupled plasma atomic emission spectrometry (ICP-AES), and their ability regarding multi element quantification in complex samples. Sensitivity, repeatability, reproducibility and accuracy were investigated. The aim was to increase the over all efficiency, the speed of analysis, and/or the sensitivity of the analytical method. The intention was to measure analytes with concentrations ranging from ng/g to mg/g simultaneously. The aim was additionally to study chemical and physical processes occurring during the sample preparation, the sample transport to the plasma, and the atomization therein. In the first sample preparation strategy, a hydrophilic highly cross-linked iminodiacetate-agarose adsorbent, IDA-Novarose, was used for preconcentration of metal ions, and matrix elimination in natural water samples. The sorbent was synthesized with different binding capacities. The effect of the capacity on preconcentration, matrix elimination, and uptake capability at high flow rates was studied. For a high capacity IDA-Novarose (≥ 45 µmole/ml) quantitative uptake was seen even at high flow rates (100 ml/min) for Cu2+ with a high affinity to the adsorbent, and for Cd2+ with a moderate affinity. For lower capacities the uptake of Cd2+ was affected by the sample matrix and the flow rate. A method based on the determination of the conditional stability constant of the metal sorbent complex was suggested for the prediction of the sorbent capacity needed to obtain quantitative recovery and optimal matrix elimination. The sorbent was used in a flow system with online buffering for the analysis of a certified riverine water (SLRS-3), tap water and lake water. With few exceptions the results obtained by ICP-AES after preconcentration agreed well with the certified concentrations and results obtained by ICP-MS. The other sample preparation strategy discussed is a method for non digested biological samples from different animal organs for the multi element analysis by ICP-AES. This “mix and measure method” consists of a simple homogenization of the sample with a mixing rod in a small amount of neutral media, followed by dilution and direct measurement with ICP-AES. The total time of analysis is only a few minutes. The ability of this fast method to accurately quantify some elements of toxic, environmental, and/or physiological concern with the lowest possible sample dilution and the highest possible plasma load was evaluated. In 10 % liver slurry Cd, Co, and Sr, at concentration levels around 0.05 µg/g were quantified simultaneously with P and K around 2000 µg/g and with several other elements in between (Al, Ca, Cu, Fe, Mg, Mn, Pb, and Zn). The relative standard deviation of repeated measurements of samples was around 5 - 6 % for regardless of the concentration of the element. The method was also used for fast screening of the elemental distribution in mice organs (brain, heart, kidney, liver, lung and spleen).
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| 5. |
- Kollander, Barbro, et al.
(author)
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Multi-Element Assessment of Potentially Toxic and Essential Elements in New and Traditional Food Varieties in Sweden
- 2023
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In: Foods. - : MDPI. - 2304-8158. ; 12:9
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Journal article (peer-reviewed)abstract
- 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.
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| 6. |
- Stedt, Kristoffer, 1991, et al.
(author)
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Cultivation of Ulva fenestrata using herring production process waters increases biomass yield and protein content
- 2022
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 9:988523
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Journal article (peer-reviewed)abstract
- Ulva spp. (sea lettuce) has recently gained attention as a sustainable protein source due to its high productivity and many nutritional properties interesting for the food industry. In this study, we explored a possible industrial symbiosis between herring production processing industries and Ulva fenestrata cultivation. We show that U. fenestrata cultivated in herring production process waters had four to six times higher biomass yields (27.17 - 37.07 g fresh weight vs. 6.18 g fresh weight) and three times higher crude protein content (> 30% dry weight vs. 10% dry weight) compared to U. fenestrata cultivated in seawater. Along with the elevation of protein, the herring production process waters also significantly increased levels of all essential amino acids in the seaweed biomass. The content of some heavy metals (arsenic, mercury, lead, and cadmium) was well below the maximum allowed levels in foodstuff. Therefore, quantities of biomass around 100 g dry weight could be consumed daily following the US Environmental Protection Agency’s reference doses. Combined, the results show that cultivation of U. fenestrata in herring production process waters has great potential to produce sustainable proteins for the growing world population. At the same time, nutrients of currently discarded process waters are circulated back to the food chain.
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| 7. |
- Stedt, Kristoffer, 1991, et al.
(author)
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Post-harvest cultivation with seafood process waters improves protein levels of Ulva fenestrata while retaining important food sensory attributes
- 2022
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745.
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Journal article (peer-reviewed)abstract
- Seaweed aquaculture can provide the growing human population with a sustainable source of proteins. Sea-based cultivation is an effective method for farming seaweeds on a large scale and can yield high biomass output. However, the quality and biochemical composition of the biomass is seasonally dependent, which limits the harvests to certain periods of the year. Here we show the possibility to extend the sea-based cultivation season of Ulva fenestrata when aiming for high protein levels, by post-harvest treatment in herring production process waters. We harvested U. fenestrata at an optimal period in terms of yield, but suboptimal in terms of protein content. We then cultivated the seaweed in onshore tank systems with the nutrient-rich process waters for 14 days. We monitored biomass yield, crude protein content, amino acid composition, and content of the health concerning metals arsenic, mercury, lead, and cadmium, as well as the sensory properties of the dried biomass. After cultivation in the process waters, biomass yields were 30 - 40% higher (210 – 230 g fresh weight) compared to in seawater (160 g fresh weight). Also, the crude protein and amino acid content increased three to five times in the process waters, reaching 12 - 17 and 15 – 21% dry weight, respectively. The protein enriched biomass followed food graded standards for heavy metal content, and consumption of the biomass does not exceed health based reference points. Additionally, no sensory attributes regarded as negative were found. This rapid, post-harvest treatment can help extend the cultivation season of sea-based seaweed farms, maximizing their output of sustainable proteins.
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| 8. |
- Steinhagen, Sophie, et al.
(author)
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Harvest time can affect the optimal yield and quality of sea lettuce (Ulva fenestrata) in a sustainable sea-based cultivation : Seasonal Cultivation of Ulva fenestrata
- 2022
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 9
-
Journal article (peer-reviewed)abstract
- Seaweed biomass is a renewable resource with multiple applications. Sea-based cultivation of seaweeds can provide high biomass yields, low construction, operation, and maintenance costs and could offer an environmentally and economically sustainable alternative to land-based cultivations. The biochemical profile of sea-grown biomass depends on seasonal variation in environmental factors, and the optimization of harvest time is important for the quality of the produced biomass. To identify optimal harvest times of Swedish sea-based cultivated sea lettuce (Ulva fenestrata), this study monitored biomass yield, morphology, chemical composition, fertility, and biofouling at five different harvesting times in April - June 2020. The highest biomass yields (approx. 1.2 kg fw [m rope]-1) were observed in late spring (May). The number and size of holes in the thalli and the amount of fertile and fouled tissue increased with prolonged growth season, which together led to a significant decline in both biomass yield and quality during summer (June). Early spring (April) conditions were optimal for obtaining high fatty acid, protein, biochar, phenolic, and pigment contents in the biomass, whereas carbohydrate and ash content, as well as essential and non-essential elements, increased later in the growth season. Our study results show that the optimal harvest time of sea-based cultivated U. fenestrata depends on the downstream application of the biomass and must be carefully selected to balance yield, quality, and desired biochemical contents to maximize the output of future sea-based algal cultivations in the European Northern Hemisphere.
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| 9. |
- Trigo, João Pedro, 1995, et al.
(author)
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Mild blanching prior to pH-shift processing of Saccharina latissima retains protein extraction yields and amino acid levels of extracts while minimizing iodine content
- 2023
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In: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 404
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Journal article (peer-reviewed)abstract
- The seaweed Saccharina latissima is often blanched to lower iodine levels, however, it is not known how blanching affects protein extraction. We assessed the effect of blanching or soaking (80/45/12 °C, 2 min) on protein yield and protein extract characteristics after pH-shift processing of S. latissima. Average protein yields and extract amino acid levels ranked treatments as follows: blanching-45 °C ∼ control > soaking ∼ blanching-80 °C. Although blanching-45 °C decreased protein solubilization yield at pH 12, it increased isoelectric protein precipitation yield at pH 2 (p < 0.05). The former could be explained by a higher ratio of large peptides/proteins in the blanched biomass as shown by HP-SEC, whereas the latter by blanching-induced lowering of ionic strength, as verified by a dialysis model. Moreover, blanching-45 °C yielded a protein extract with 49 % less iodine compared with the control extract. We recommend blanching-45 °C since it is effective at removing iodine and does not compromise total protein extraction yield.
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