9 research outputs found

    Natural preservatives in meat products

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    The use of preservatives in industrial food production is now common practice. However, there is growing concern among consumers over the harmful effects of common chemical preservatives. As a result, there is increased demand for food that that has undergone little or no processing. In recent years, there has therefore been great interest in finding alternatives to chemical preservatives for use in the meat industry, in the form of natural ingredients. Possible solutions include the use of plant extracts, essential oils or antimicrobial peptides. This paper provides a review of research on the replacement of artificial preservatives in meat products with traditional chemical compounds of natural origin

    Fluid types and their genetic meaning for the BIF belt formation, Krivoy Rog, Ukraine

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    Promotor: Adam Piestrzyński.Recenzent: Andrzej Kozłowski, Marek Michalik.Niepublikowana praca doktorska.Tyt. z ekranu tyt.Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków). Katedra Geologii Złożowej i Górniczej, 2014.Zawiera bibliogr.Dostępna również w wersji drukowanej.Tryb dostępu: Internet.Regional geology, lithostratigraphy, tectonic framework, metamorphism, metasomatism, ore mineralization, ore minerals, classification of Fe ores, iron ore genesis, origin of quartz from the Krivoy Rog BIF, previous studies of fluid inclusions within the Krivoy Rog BIF, research area and rock material, methodology, fluid inclusion petrography, low-grade iron ore, quartz bands of the low-grade iron ore, petrography of the veins, fluid inclusion petrography – vein 1 and vein 2, iron-rich quartzites, thrust zone, microthermometry, low-grade iron ore, iron-rich quartzites, thrust zon

    Polyphenolic Herbal Extract of Cistus incanus as Natural Preservatives for Sausages Enriched with Natural Colors

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    This study evaluates the effects of polyphenolic extract of Cistus incanus, lycopene dye from tomatoes, and betanin dye from red beet on selected parameters of model meat products with reduced nitrate contents. The polyphenolic composition and activity of the C. incanus extract was analyzed, revealing the presence of elagotannins, flavanols, and glycosylated flavanols. We studied the effects of the extract and dyes as well as of mixtures of the extract and dyes on the growth of bacteria characteristic of the meat environment: E. coli, S. enterica, P. fragi, L. monocytogenes, B. thermosphacta, and L. sakei. We studied the effects of the extract and dyes on the lipid oxidation, color, and microbiological quality of pork sausages with reduced nitrate content over 28 days of storage. During storage, the amounts of malon dialdehyde reduced, which indicates that the extract and dyes exhibited antioxidant activity and slowed lipid oxidation in the sausages. An increase in red color was also observed in the sausages with natural additives, despite their decreased nitrate content. It was found that the C. incanus extract combined with coloring agents positively influenced the selected parameters of the analyzed pork sausages

    REY and Trace Element Chemistry of Fluorite from Post-Variscan Hydrothermal Veins in Paleozoic Units of the North German Basin

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    Hydrothermal fluorites from Paleozoic sedimentary rocks and volcanic units in the North German Basin (NGB) have been investigated to create a petrographic and geochemical inventory—with particular focus on strategic elements such as rare earth elements (REE)—and to uncover possible links between the post-Variscan hydrothermal mineralization in the NGB and bordering areas such as the Harz Mountains and Flechtingen Calvörde Block (FCB). Fluorites from ten localities underwent a detailed petrographic examination, including SEM-BSE/CL imagery, and were compositionally analysed using LA-ICP-MS. Overall, REY concentrations are comparatively low in fluorite from all investigated areas—the median sum of REY ranges from 0.3 to 176 ppm. EuropiumCN anomalies are slightly negative or absent, indicating that either the formation fluid experienced temperatures above 250 °C or that fluid-rock interactions and REE enrichment was likely controlled by the source rock (i.e., volcanic) composition and complexation processes. Fluorites from the Altmark-Brandenburg Basin (ABB) and the Lower Saxony Basin (LSB) display distinctly different REYCN signatures, suggesting that fluid compositions and genetic processes such as fluid-rock interaction differed significantly between the two areas. Complex growth zones and REYCN signatures in fluorite from the ABB and the FCB reflect geochemical variability due to adsorption processes and intrinsic crystallographic controls and imply that they are genetically related. Two petrographically and geochemically distinct generations are observed: Fluorite I—light SEM shades, relatively enriched in LREE; Fluorite II—darker SEM shades, comparatively depleted LREE, slightly higher HREE concentrations. These fluorite generations represent zoned (or cyclical) growth within a single progressive hydrothermal event and do not reflect a secondary remobilization process. We demonstrate that increasing Tb/La ratios and decreasing La/Ho ratios can be the result of continuous zoned growth during a single mineralizing event, with significant compositional variations on a micron-scale. This has implications for the interpretation of such trends and hence the inferred genetic evolution of fluorite that displays such geochemical patterns. The complex micro-scale intergrowth of these generations stresses the need for detailed petrographic investigations when geochemical data are collected and interpreted for mineral exploration

    The Schlaining quartz-stibnite deposit, Eastern Alps, Austria: constraints from conventional and infrared microthermometry and isotope and crush-leach analyses of fluid inclusions

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    Stibnite was mined until the end of the twentieth century in the Schlaining ore district, Austria, near the easternmost border of the Eastern Alps where windows of Penninic ophiolites and metasediments are exposed below Austroalpine tectonic units. In Early Miocene, structurally controlled small vein and metasomatic stibnite-quartz deposits were formed in Penninic Mesozoic calcareous marbles and calcite schists. Fluid inclusion studies identified two fluids involved in the mineralization: (i) a low-salinity, low-CO2 metamorphic fluid that precipitated quartz at approximately 240 °C and (ii) a stibnite-forming ore fluid that had a meteoric origin. There is no evidence of boiling or that the fluids mixed during mineralization. The ore components Sb and H2S were leached by fluid/rock interaction from buried rock units. Stibnite mineralization occurred by cooling the ore fluid to below 300 °C, at less than 2000 m depth. Quartz precipitated at slightly lower temperatures, approximately contemporaneous with stibnite. Fluid migration and ore deposition are probably related to high heat flow during the exhumation of the Rechnitz Window in response to Neogene extension and/or shallow Early Miocene andesitic magmatism. The study emphasizes that data obtained from the analyses of gangue minerals alone cannot routinely be used to infer the origin and depositional conditions of the associated ore minerals.Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum - GFZ (4217

    Metal budget and origin of aqueous brines depositing deep-seated Zn-Pb mineralization linked to hydrocarbon reservoirs, North German Basin

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    The origin, evolution, and interplay of brine and hydrocarbon fluid systems play a crucial role in the formation of deep sediment-hosted base metal ore deposits. Here we investigate ratios of halogens, noble gases, stable C and S isotopes, and metal budgets of aqueous brines, which deposited deep-seated and near-surface hydrothermal Zn-Pb mineralization hosted by Zechstein carbonates in the Lower Saxony Basin (North German Basin), by studies of fluid inclusions in sphalerite and quartz. Major and trace element geochemistry and noble gas isotopic signatures of brine inclusions revealed that the ore-forming fluids were highly reactive and experienced prolonged interactions with host rocks in the constricted, over-pressured metal source regions and consequently evolved from near-neutral, oxidized brines towards more reduced, acidic high-salinity brines. Quartz-hosted halite-saturated fluid inclusions with T-h <200 degrees C contain Zn and Pb concentrations up to ca. 9400 mu g g(-1) and 5200 mu g g(-1), respectively, and indicate the efficiency of metal scavenging processes. The interactions with Westphalian coals and C-org-rich shales influenced the redox state as well as the trace and critical element budget of the sphalerite-hosted fluid inclusions, with enrichment in Ge, Pd, Sb, Tl, Bi, and Ag. The salinities of metalliferous fluids originated primarily from seawater evaporation, however in addition a significant halite-dissolution component is present in the southern part of the Lower Saxony Basin. High concentrations of radiogenic noble gases and potassium in the sphalerite-hosted fluid inclusions are ascribed to strong interactions with the Paleozoic siliciclastic sedimentary pile and crystalline basement rocks. Reflux of the strongly modified, sulfur-poor, Zn-Pb-bearing acidic brines, proceeded via re-activated structurally controlled pathways into sour gas or gas-saturated brine pools in the Zechstein Ca2 carbonate unit. Here, mixing of the ascending metal-rich brines with H2S derived from thermochemical sulfate reduction (TSR), resulted in the deposition of deep-seated Zn-Pb ores in the Lower Saxony Basin. The overall timing of the Zn-Pb ore formation can be constrained to the Upper Cretaceous basin inversion.ISSN:0026-4598ISSN:1432-186
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