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Stalazs A.,Latvia State Institute of Fruit Growing
Acta Horticulturae | Year: 2012

Currants are the second most important berry crops in Latvia. During the last ten years the increase of gall mites (genus Cecidophyopsis) in Latvia in several currant plantations was observed. However, the distribution of the gall mites was unclear and in 2008 gall mite distribution and faunal studies were started. Sixty-five localities in Latvia were inspected and gall mites were observed in 38 of the 65 locations. Gall mites were observed from all types of inspected areas and on plants from three currant groups - blackcurrants (Ribes, subg. Ribes sect. Botrycarpum), redcurrants (Ribes, subg. Ribes sect. Ribes) and alpine currants (Ribes, subg. Berisia sect. Berisia). In commercial currant plantations, the blackcurrant cultivars 'Katyusha' and 'Mara Eglite' were most susceptible to gall mites. The blackcurrant cultivar 'Titania' was highly infested only in some areas. Gall mites are also a serious problem in currant plant genetic resource collections.

Gornas P.,Latvia State Institute of Fruit Growing | Siger A.,University of Life Sciences in Poznan | Polewski K.,University of Life Sciences in Poznan | Pugajeva I.,Institute of Food Safety | Waskiewicz A.,University of Life Sciences in Poznan
European Food Research and Technology | Year: 2014

Qualitative and quantitative determination of tocopherols in filtered and unfiltered coffee brews was investigated. The NP-HPLC/FLD and RP-UPLC-ESI/MSn techniques as well as fluorescence spectroscopy turned out to be very useful tools not only to estimate tocopherol contents, but also to detect contaminants in coffee brew tocopherol extracts. In all analysed coffee brew samples, only α- and β-T were detected. In Arabica coffee brews, the content of the β homologue was three to four times higher than that of the α homologue; however, in Robusta, they were almost identical. Unfiltered coffee brews contained about ten times more tocopherols, 3.02-5.26 and 3.39-16.52, than filtered brews, 0.4-0.71 and 1.26-1.77 μg/100 ml for α-T and β-T, respectively. The reduction in the size of ground coffee beans from 0.7 to 0.3 mm increases the concentration of tocopherols almost three times. Suspended coffee bean dust was the main source of tocopherols in coffee brews. © 2013 Springer-Verlag Berlin Heidelberg.

The tocochromanol profile was studied in seed oils recovered from by-products of fruit industry, five dessert and seven crab apple varieties grown in Eastern Europe (Latvia). The seed oils obtained from dessert apples were characterized by higher contents of tocopherols (191.05-379.08 mg/100 g oil) when compared to seed oils recovered from crab apples (130.55-202.54 mg/100 g oil). The predominant homologues of tocopherol in all the studied samples were α and β over γ and δ. However, seed oils recovered from the apple cultivars 'Antej' and 'Beforest' had a unique profile of four tocopherol homologues (α:β:γ:δ) 91.41:80.55:72.46:79.03 and 114.55:112.84:78.69:73.00 mg/100 g oil, respectively. A single dilution of seed oils in 2-propanol facilitated the direct use samples in the DPPH assay as well as injection into the RP-HPLC system containing a PFP (pentafluorophenyl) column, which resulted in a rapid separation of all four tocopherol homologues with excellent repeatability and reproducibility. © 2014 Elsevier Ltd. All rights reserved.

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 | Year: 2014

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.

Gornas P.,Latvia State Institute of Fruit Growing | Siger A.,University of Life Sciences in Poznan | Pugajeva I.,Institute of Food Safety | Seglina D.,Latvia State Institute of Fruit Growing
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2014

Thirteen cold-pressed oils (Japanese quince seed, black caraway, flaxseed, rapeseed, hemp, peanut, sunflower, pumpkin, hazelnut, poppy, walnut, almond and sesame oil) manufactured by the same company over a 2-year period (2011-12) were assessed for lipophilic compounds. The presence of sesamin and sesamolin, two characteristic lignans of sesame oil, were detected in all tested plant oils. Both lignans were identified by NP-HPLC/FLD/DAD and confirmed by a RP-UPLC-ESI/MSn method. The lowest amount of sesamin and sesamolin was found for Japanese quince seed oil (0.10 and 0.27 mg/100 g), and the highest, excluding sesame oil, for almond oil (36.21 and 105.42 mg/100 g, respectively). The highly significant correlation between sesamolin and sesamin concentrations was found in all samples tested (r = 0.9999; p < 0.00001). These results indicate contamination of cold-pressed oils from the same source. This investigation highlights the fact that increasing the range of products manufactured by the same company can contribute to a lesser regard for the quality of the final product. Moreover, less attention paid to the quality of final product can be related to the health risks of consumers especially sensitive to allergens. Therefore, proper cleaning of processing equipment is needed to prevent cross-contact of cold-pressed oils. © 2014 Taylor & Francis.

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