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Jūrmala, Latvia

Gornas P.,Latvia State Institute of Fruit Growing | Seglina D.,Latvia State Institute of Fruit Growing | Lacis G.,Latvia State Institute of Fruit Growing | Pugajeva I.,Institute of Food Safety
LWT - Food Science and Technology

Tocochromanols composition in apple seeds, obtained as a by-product during the fruit salad and juice production, of twelve varieties - seven crab apple ('Kerr', 'Kuku', 'Quaker Beauty', 'Riku', 'Ritika', 'Ruti' and K-8/9-24) and five dessert apples ('Antej', 'Beforest', 'Kent', 'Sinap Orlovskij' and 'Zarja Alatau') were studied. Tocopherols and tocotrienols were isolated using the micro-saponification method of high precision and accuracy and they were analysedanalysed by rapid RP-HPLC/FLD and RP-UPLC-ESI/MSn. Four tocopherols, with predominance of homologues α and β, were detected in each tested sample. The seeds from two apple cultivars 'Antej' and 'Beforest' were characterized by unique and similar ratios of all four tocopherol homologues α:β:γ:δ (1.7:1.5:1.3:1.0 and 2.1:2.0:1.3:1.0, respectively). The concentration range of individual tocopherol homologues (α, β, γ and δ) in apple seeds were as follows: 17.22-25.79, 7.53-29.05, 0.61-13.82 and 0.16-10.79mg/100g dry weight basis (dwb), respectively. Moreover, three tocotrienols (α, β and γ) were identified in lesser amounts (0.02-0.74 mg/100g dwb). Use of apple seeds to isolate tocopherol homologues can ensure better environmental sustainability and effective use of natural plant material. © 2014 Elsevier Ltd. Source

This study analyses the structure of fish communities in 201 Latvian rivers: the number of species, their diversity, abundance and biomass of fish in accordance with the nationally accepted river typology and its parameters, i.e. the river basin area and the average slope. The number of species and their diversity as well as the abundance and biomass of fish vary significantly in rivers with different basin areas and temperature regimes. Latvian rivers can be classified into the following types based on the fish communities therein: (I) small coldwater rivers with trout and stone loach as dominant species, (II) small warmwater rivers dominated by stone loach, minnow, pike and perch, (III) medium coldwater rivers with such dominant species as brook lamprey, trout, minnow, stone loach and sculpin, (IV) medium warmwater rivers with pike, roach, gudgeon, minnow, stone loach and perch as dominant species, and (V) large potamal warmwater rivers dominated by pike, roach, chub, gudgeon, minnow, riffle minnow, bleak, stone loach, loach and perch. This study has not analysed anthropogenic impact, therefore the fish-based river typology needs further development. Copyright © 2012 Nature Research Centre. Source

Gornas P.,Latvia State Institute of Fruit Growing | Pugajeva I.,Institute of Food Safety | Seglina D.,Latvia State Institute of Fruit Growing
European Food Research and Technology

Tocochromanol composition was analysed in the seeds of nine various fruits: apple (Malus domestica Borkh.), red currant (Ribes rubrum L.), gooseberry (Ribes uva-crispa L.), grape (Vitis vinifera L.), pomegranate (Punica granatum L.), Japanese quince (Chaenomeles japonica (Thunb.) Lindl. ex Spach), sea buckthorn (Hippophae rhamnoides L.), watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) and canary melon (Cucumis melo L.), recovered from by-products of fruit industry. The concentration range of subsequent tocopherols (Ts) and tocotrienols (T3s) was as follows: 1.29-29.30, 0.00-11.68, 0.42-95.11, 0.00-7.66, 0.03-5.03, 0.00-0.18 and 0.00-6.68 mg/100 g of seed dry weight for α-T, β-T, γ-T, δ-T, α-T3, β-T3 and γ-T3, respectively. The δ-T3 was not detected in any of the tested seeds. All tocochromanols were successfully separated by rapid RP-HPLC/FLD method and confirmed by the RP-UPLC-ESI/MS3 technique. © 2014 Springer-Verlag Berlin Heidelberg. Source

Casini M.,Swedish University of Agricultural Sciences | Blenckner T.,University of Stockholm | Mollmann C.,University of Hamburg | Gardmark A.,Swedish University of Agricultural Sciences | And 6 more authors.
Proceedings of the National Academy of Sciences of the United States of America

Understanding the effects of cross-system fluxes is fundamental in ecosystem ecology and biological conservation. Source-sink dynamics and spillover processes may link adjacent ecosystems by movement of organisms across system boundaries. However, effects of temporal variability in these cross-system fluxes on a whole marine ecosystem structure have not yet been presented. Here we show, using 35 y of multitrophic data series from the Baltic Sea, that transitory spillover of the top-predator cod from its main distribution area produces cascading effects in the whole food web of an adjacent and semi-isolated ecosystem. At varying population size, cod expand/contract their distribution range and invade/retreat from the neighboring Gulf of Riga, thereby affecting the local prey population of herring and, indirectly, zooplankton and phytoplankton via top-down control. The Gulf of Riga can be considered for cod a "true sink" habitat, where in the absence of immigration from the source areas of the central Baltic Sea the cod population goes extinct due to the absence of suitable spawning grounds. Our results add a metaecosystem perspective to the ongoing intense scientific debate on the key role of top predators in structuring natural systems. The integration of regional and local processes is central to predict species and ecosystem responses to future climate changes and ongoing anthropogenic disturbances. Source

A new analytical method was established and validated for the analysis of 27 brominated flame retardants (BFRs), including so called "emerging" and "novel" BFRs (EBFRs and NBFRs) in fish samples. High performance liquid chromatography (HPLC) coupled to Orbitrap mass spectrometry (Orbitrap-MS) employing atmospheric pressure photoionization (APPI) interface operated in negative mode was used for the identification/quantitation of contaminants. HPLC-Orbitrap-MS analysis provided a fast separation of selected analytes within 14 min, thus demonstrating a high throughput processing of samples. The developed methodology was tested by intralaboratory validation in terms of recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ), and where possible, trueness was verified by analysis of certified reference materials (CRMs). Recoveries of analytes were between 80 and 119%, while the repeatability in terms of relative standard deviations (RSDs) was in the range from 1.2 to 15.5%. The measured values for both analyzed CRMs agreed with the provided consensus values, revealing the recovery of reference concentrations in 72-119% range. The elaborated method met the sensitivity criterion according to Commission Recommendation 2014/118/EU on monitoring of BFRs in food products for majority of the compounds. The concentrations of polybrominated diphenyl ethers (PBDEs) in real samples determined by HPLC-APPI-Orbitrap-MS method and validated gas chromatography-high-resolution mass spectrometry (GC-HRMS) method were found to be in a good agreement. © 2015 Elsevier B.V. Source

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