Przeglądaj wg Autor "Bienkiewicz, Grzegorz"

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    PozycjaOpen Access
    Porównanie metod przygotowania estrów metylowych kwasów tłuszczowych wg AOAC oraz metodą bezpośrednią przy oznaczaniu składu kwasów tłuszczowych tkanki mięsnej ryb
    (Wydawnictwo Uczelniane Zachodniopomorskiego Uniwersytetu Technologicznego w Szczecinie, 2010) Domiszewski, Zdzisław; Bienkiewicz, Grzegorz; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    Analysis of the composition of lipids is done by separating fatty acids (FA), most often through gas chromatography, after converting FA into their volatile derivatives: fatty acid methyl esters (FAME). The aim of the paper was to compare the results of analysis FA composition of three species of oily fish, both raw and subjected to heat treatment, by converting FA into FAME applying the AOAC method, and using the direct method. FAME were separated by gas chromatography-coupled mass spectrometry (GC-MS). It was shown that, in fish subjected to heat treatment, the percentages of EPA and DHA whose FAME were prepared via the direct method were 5-10% higher than in case of applying the AOAC method. As far as uncooked oily fish are concerned, the method of obtaining FAME had no relevance to the composition of fatty acids. The method of obtaining FAME can have a substantial impact on the percentages of individual acids or acid groups in fat, and, in turn, on results of evaluation its nutritional value.
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    PozycjaOpen Access
    Susceptibility to Oxidation of Selected Freshwater Fish Species Lipids as a Potential Source of Fish Oil in Dietary Supplements
    (Hindawi, 2021-08-20) Tokarczyk, Grzegorz; Bienkiewicz, Grzegorz; Biernacka, Patrycja; West Pomeranian University of Technology in Szczecin
    Polyunsaturated fatty acids from the omega 3 family are more and more often supplied to the diet in the form of supplements. The aim of the study was to characterize the lipid fractions of predatory freshwater fish, i.e., pike (Esox lucius L.), perch (Perca fluviatilis L.), and pike perch (Sander lucioperca L.), and omnivorous fish, i.e., bream (Abramis brama L.) and roach (Rutilus rutilus L.). Their technological usefulness in terms of the source of fish oil was determined, depending on the rate and degree of their oxidative changes. UV radiation (photooxidation test) was used as a factor accelerating lipid oxidation. Research has shown that selected species of freshwater fish are characterized by high lipid oxidative stability, due to the availability and speed of delivery to the processing plant. The initial level of lipid oxidation of their meat, expressed by the TOTOX index, in any species did not exceed the value of 7, while the acceptable value was 26. The oil obtained from the meat of omnivorous fish after the photooxidation process was characterized by significantly better oxidative stability compared to the oil from the meat of predatory fish. The oxidation resistance of omnivorous fish oil was shown to be higher than that of predatory fish.
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    PozycjaOpen Access
    Wpływ mrożenia na proces dojrzewania odgłowionego i patroszenia śledzia bałtyckiego solonego metodą zalewową
    (Wydawnictwo Uczelniane Zachodniopomorskiego Uniwersytetu Technologicznego w Szczecinie, 2010) Tokarczyk, Grzegorz; Kołakowski, Edward; Bednarczyk, Bożena; Szymczak, Mariusz; Przybylska, Sylwia; Waliłko, Anna; Lament, Katarzyna; Krzywiński, Tomasz; Bienkiewicz, Grzegorz; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Technologii Żywności, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    Ripening of fresh and frozen/thawed headed and gutted Baltic herring salted in 12% NaCl solution (brine) with or without the addition of 0.7% acetic acid was compared. Samples for assays were taken after 2, 3, 4, 5, 7, 10, 14, 18, 21 and 27 days of ripening. Control samples for assays were taken after 1, 3, 5, 7, 9, 11, 15 and 18 days of ripening. Herring meat and brine were assayed separately. Freezing of raw material reduced the growth of protein hydrolysis products (peptides and thyrosine), however the contents of peptides and thyrosine were high than in fresh fish, especially in brine and brine meat extract with acetic acid. Freezing of raw material had a significant impact on the ripening of Baltic herring salted in brine. Fundamental differences depended on initial processing and chemical composition of brine. Acetic acid inhibited ripening of salted frozen/thawed herring. Baltic herring salted in the presence of CH3COOH had better quality then salted in brine without CH3COOH regardless of initial processing. On the other hand the best quality had salted products made from fresh/unfrozen Baltic herring.
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    PozycjaOpen Access
    Zawartość histaminy w owocach. Doniesienie
    (Wydawnictwo Uczelniane Zachodniopomorskiego Uniwersytetu Technologicznego w Szczecinie, 2012) Czerniejewska-Surma, Barbara; Surma, Orina; Plust, Dominika; Bienkiewicz, Grzegorz; Zakład Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Zakład Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Zakład Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Zakład Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    Histamine is well known biogenic amine. This amine plays an important role in the human body and may pose a risk to human health and life. Knowledge of the histamine content in food products and consequences of its formation are very important for food technologist. The aim of this study was to determine the histamine content in the fruits from polish plant and from import. Material for the analyses were: pome fruits, stone fruits, berries, nuts and tropical fruits. Histamine content was determined by the colorimetric method according to PN-87-A-86784. The amount of histamine ranged from 2.15 to 31.04 mg · kg–1. The highest content of histamine was observed in lemons. Among the studied groups of fruits contain the most of histamine content have pome fruit, then nuts, tropical fruits, berries and stone fruits. The obtained results show that none of the studied fruits did not contain histamine above of allowable limits.
  • Miniatura
    PozycjaOpen Access
    Zawartość polifenoli, właściwości przeciwutleniające oraz zdolności redukujące naparów herbat białych liściastych
    (Wydawnictwo Uczelniane Zachodniopomorskiego Uniwersytetu Technologicznego w Szczecinie, 2011) Plust, Dominika; Czerniejewska-Surma, Barbara; Domiszewski, Zdzisław; Bienkiewicz, Grzegorz; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Towaroznawstwa i Oceny Jakości, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie
    This paper defines the content of polyphenols, antioxidant activity against ABTS radicals and reducing power (FRAP) of white tea infusions. To determine total polyphenol content using the assay with Folin-Ciocalteau reagent, antioxidant properties was determined by TEAC and FRAP assay. It was demonstrated that white tea infusions have high antioxidant properties but varying dependent on size of the leaves.