The antioxidant and antimicrobial properties of Boletus edulis decoction and the effect of mushroom addition on the physicochemical and microbiological properties of frankfurters during refrigerated ...storage were studied. The addition of mushroom delayed the increase in the total number of aerobic mesophilic microorganisms during the storage. The incorporation of B. edulis in cooked sausages resulted in the significantly higher hardness of frankfurters in comparison with control, during chilled storage. Mushroom addition significantly affected the color of sausages throughout storage, but no deficiencies in sensory acceptance test were obtained. Generally, this mushroom can be used as a natural antioxidant to interfere with microorganism growth and extend the shelf life of cooked pork sausages during refrigerated storage.
Practical applications
In this study, the addition of B. edulis has proven to be a potent antioxidant and antimicrobial ingredient that extends the shelf life of frankfurters. That could be an interesting finding in potentially reducing or replacing commercial antioxidants with a natural, healthier variant of food additives.
Nanocrystals of Y2O3 and La2O3 solid solutions were synthesized with a cubic bixbyite structure containing La2O3 content of up to 50mol%. This is comparatively higher than that in bulk materials of ...the same structure, where La2O3 content of only 20mol% can be obtained. A set of europium-doped (Y1−xLax)2O3 (x=0.1, 0.2, 0.3, 0.4) cubic bixbyite solid solutions with crystallites of approximately 10nm in size was prepared using the polymer complex solution method. Structural analysis was performed using X-ray diffraction measurements, Rietveld full profile refinement, and from Eu3+ luminescence emission. The energy levels of the Eu3+ ion, second order crystal field parameters, and crystal field strength were obtained for all compositions of solid solutions. We show that the crystal field parameters linearly depend on unit cell parameter and that these dependencies may be considered as part of an overall dependence for the entire sesquioxide family.
•Nanoparticles of cubic Y2O3–La2O3 are prepared for La2O3 content of up to 50mol%.•Energy levels of Eu3+ in (Y1−xLax)2O3 are derived from photoluminescence spectra.•Second-order crystal field parameters and crystal field strength are calculated.•Stark splitting of 7F1 manifold (ΔE) linearly varies with the crystal field strength.•Semi-empirical equation relating the unit cell parameter with the ΔE is derived.
Display omitted
•Synthesis and characterization of Ag2CO3 and AgX/Ag2CO3 composites.•Improved photocatalytic performance and stability of formed heterostructures.•Photocatalytic mechanism concerning ...redox potential of reaction species.
The synthesized rod-like Ag2CO3 particles (2–4×0.3–0.6μm, length×diameter) served as a precursor for preparation of the AgX/Ag2CO3 (X=Cl, I) composites by ion exchange method. The various microstructural (X-ray diffraction analysis, transmission electron microscopy, nitrogen adsorption-desorption isotherms) and optical (diffuse reflection spectroscopy) techniques were used for thorough characterization of obtained heterostructures. The enhanced photocatalytic performance of AgX/Ag2CO3 heterostructures in comparison to Ag2CO3 nanorods (NRs) was evidenced using degradation of organic dye methylene blue as a test reaction. Also, the formation of composites improved their stability under long run illumination conditions. The effect of AgX content on photocatalytic activity of the composites were also investigated. The possible photocatalytic mechanism that facilitates efficient separation of photo-formed charge carriers in heterostructures was discussed in terms of the relative energetic of valence and conduction bands.
The aim of this study was to examine the effect of added sunflower, linseed or soybean meal to a standard pig fattening diet on the chemical composition, fatty acid profiles of meat and backfat, and ...on the oxidative stability of backfat from pigs. The content of saturated (SFA) and monounsaturated fatty acids (MUFA) was significantly lower (
<0.01), while content of polyunsaturated fatty acids (PUFA) was significantly higher (
<0.01) in the diet with added linseed. The feeding study was conducted on 30 pigs, with groups of 10 pigs fed one of the three different diets for 46 days before slaughter. There were no differences in the chemical composition (protein, water, fat, minerals) of meat from pigs fed the different diets. The content of SFA and MUFA was significantly higher, while the average PUFA content was significantly lower (
<0.01) in meat and backfat of pigs fed diet with added linseed. The content of n-6 fatty acids was significantly lower and n-3 fatty acids significantly higher, with more desirable n-6/n-3 ratio, in meat and backfat of pigs fed diet with added linseed. Malondialdehyde in the backfat of pigs fed diet with added linseed was significantly lower than that in the other two diet groups after the tissue was stored frozen at −20°C for 3, 6, 9 and 12 months.
Caraway (Carum carvi L.) essential oil (CEO: 0.01, 0.05, 0.10 µl/g) was used in dry‐fermented sausages manufactured with 15% and 25% of fat and three levels of sodium nitrite (0, 75, 150 mg/kg). ...Dry‐fermented sausages were vacuum packed and stored (225 days) and their physico–chemical, microbial, and sensory attributes were assessed (a total of 288 dry‐fermented sausages were produced). The inclusion of CEO had a significant effect on pH, texture and color, odor, and flavor. Moreover, the partial and total replacement of sodium nitrite with CEO (0.01 µl/g) provided acceptable TBARS values (<0.3 mg MDA/kg) in low‐fat (15%) of sausages throughout the storage. The usage of CEO at 0.10 µl/g affected formation of atypical flavor. Generally, our findings confirmed that the CEO has promising potential for development of dry‐fermented sausages with reduced level of sodium nitrite, primarily regarding their oxidative stability.
Practical applications
The usage of natural antioxidants is one of the key strategies in the novel meat industry. Concerning strong antioxidant potential, CEO could be used as an emerging antioxidant and potential substitute for sodium nitrite in meat processing.
Gadolinium-oxide nanopowders doped with Yb3+ and Ho3+ ions and co-doped with alkali metal ions (Li+ and Na+) were synthesized via the polymer complex solution method and their up-conversion emission ...properties are analyzed. Prepared powders were well crystallized in cubic bixbyite structure, without any impurity phases and with an average crystallite size of about 25nm, as shown by X-ray powder diffraction analysis. No adsorbed species on the surface of nanoparticles were detected by infrared measurements. The particle morphology was analyzed by transmission electron microscopy, which revealed agglomerated crystalline nanoparticles with irregular, polygonal-like shapes, having a size in the range from 30 to 50nm. Up-conversion emission properties of Gd2O3:Ho3+,Yb3+ nanopowders were evaluated from photoluminescence emission and decay measurements using 980nm excitation. Two-photon up-conversion processes produced emissions in visible – near infrared spectral range, with the strongest green emission from 5F4,5S2→5I8 Ho3+ electronic transition, and weak red and near infrared from 5F5→5I8 and 5F4, 5S2→5I7 transitions, respectively. In addition, three-photon up-conversion emission was detected in ultra-violet–blue spectral region (5G4→5I8, 3D3→5I6 and 5G5→5I8 transitions). Luminescence measurements were performed on samples with different Ho3+ (0.5 and 1at%) and Yb3+ (2, 4 and 6at%) concentrations to find that 0.5at% of Ho3+ and 2at% of Yb3+ provides the most intense up-conversion emission. The influence of alkali metal (Li+ and Na+) ion co-doping is studied on the sample that showed the most intense up-conversion emission. Increase in the intensity of up-conversion emission is observed for both Li+ and Na+ co-doping. The effect is more pronounced with Li+, where addition of 5at% of Li+ led to more than one order of magnitude emission enhancement. Alkali metal ion co-doping also significantly improved up-conversion color purity through considerably larger increase of green emission compared to red and near infrared.
•Gd2O3:Yb3+, Ho3+ co-doped with alkali metal ions are prepared by the combustion method.•Optimal doping concentrations for UC is 0.5at% of Ho and 2at% of Yb.•Increase of UC emission intensity is observed for both Li+ and Na+ co-doping.•5at% of Li+ addition leads to more than one order of magnitude emission enhancement.•Alkali metal ions co-doping significantly improved up-conversion color purity.
PDF
