RESUMO
In this study, super-hydrophobic coatings on Al surfaces were prepared by a two-step chemical etching process using potassium hydroxide and lauric acid as the etching solution and coating solution, respectively. The Al surface was roughened by immersion in potassium hydroxide, and an ethanolic solution of lauric acid was then coated onto the rough Al surface to lower the surface energy. The wettability and surface morphologies of the treated Al surfaces were characterized using contact angle measurement and scanning electron microscopy, respectively. Microstructures were formed on the treated Al surfaces, which increased the contact angle of the surface (>150°). The contact angle hysteresis was measured between 2.7° and 3° on average, indicating that the surface energy of the Al substrate was low, and the lauric acid was uniformly coated on the substrate. This super-hydrophobic coating showed excellent self-cleaning and corrosion-resistant behavior. The coated samples floated on the water surface and demonstrated excellent water repellent properties. In addition, the coatings were mechanically stable and had an excellent regeneration ability, as verified experimentally. The lauric acid used to lower the surface energy is considered more environment-friendly and more durable than the widely used polytetrafluoroethylene (PTFE).
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Titanium aluminium nitride (TiAlN) ternary coatings were deposited on glass substrates by means of reactive magnetron sputtering technique, using a Ti-Al alloy metal target (Ti0.5Al0.5). The depositions were performed at various N2 and Ar flux ratios of N2/(Ar + N2) â 33, 50, 67, 83%. The structure, morphology, chemical composition and mechanical properties were investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and nano indenter (MTS System), respectively. The orientation of coatings depends on the flux ratios of N2/(Ar + N2) and substrate temperature. The coatings deposited with N2/(Ar + N2) ratios of 33, 50 at.% consists of pyramid-like column grains separated by porous and voids, which can be attributed to cubic-TiN (220) preferred orientation. The coatings deposited with N2/(Ar + N2) greater than 67% exhibits the phase of hexagonal-AlN and cubic-TiN. The surface of coatings becomes more compact and smoother with the N2/(Ar + N2) ratios increase. The coatings deposited with N2/(Ar+N2) ratio of 83% shows the largest hardness of 21.5 GPa, which is attributed to the preferred (200) orientation. However, this hardness increases significantly with increasing substrate temperature. The coatings deposited at more than 100 °C exhibited the (111) and/or (200) orientation. The amounts of grains grown along the (111) and (200) orientations play a significant role on the mechanical performance of TiAlN coatings. Four independent mechanisms, such as TiAlN stoichiometry and lattice parameter, the (111) preferred growth orientation, and the density increases (elimination of void), were found to contribute to the enhancement of TiAlN mechanical performance.
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Mycoplasma synoviae (MS) is a common respiratory pathogen in the poultry industry. Eradication of MS from broiler breeder flocks is important for reducing economic losses caused by MS-associated diseases on broiler farms. An outbreak of MS infection was detected on a multi-age Korean broiler breeder farm that implements a flock replacement program every 3 to 6 months and uses A-type cages. Continuous administration of tilmicosin after 2 rounds of intensive antibiotics treatment with chlortetracycline, doxycycline, and enrofloxacin reduced MS shedding from the MS-positive flocks and eventually eradicated MS from the farm. Flock 3 was the last MS-positive flock by both PCR and enzyme-linked immunosorbent assay (ELISA), while flocks introduced to the farm after flock 3 were MS-negative by both PCR and ELISA at the time of depletion. This is the first report of successful eradication of MS from a multi-age broiler breeder farm using continuous antibiotic treatments.
Assuntos
Criação de Animais Domésticos/métodos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Galinhas , Infecções por Mycoplasma/veterinária , Mycoplasma synoviae/efeitos dos fármacos , Doenças das Aves Domésticas/tratamento farmacológico , Animais , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Infecções por Mycoplasma/tratamento farmacológico , Infecções por Mycoplasma/microbiologia , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/microbiologia , República da CoreiaRESUMO
This study aimed to investigate the effect of ethanolic extracts from perilla leaves (PLE) on the quality attributes and polycyclic aromatic hydrocarbons (PAHs) in charcoal-barbecued pork patties. The PLE addition and doneness had no significant effect on the pH of pork patties (p>0.05). Regardless of the concentration, the PLE significantly lower malondialdehyde concentrations and reduced the CIE L*, CIE a*, and CIE b* when compared to control. The addition of 0.2% of PLE did not adversely affect the organoleptic properties of doneness of medium and well-done pork patties. Addition of PLE at 0.4% to medium-cooked pork patties had stronger suppressing effect on the formation of light PAHs compare to control (p<0.05), also adding it to well-done pork patties had the lowest concentration of 4 PAHs and 8 PAHs, and a total of 16 PAHs (p<0.05). Therefore, PLE at 0.4% can be used for suppressing the formation of PAHs and lipid oxidation in well-cooked pork patty.
RESUMO
OBJECTIVE: This study aimed to evaluate the difference in the thigh meat quality of Ross 308 broiler from conventional and welfare farms. METHODS: Thigh meat samples of Ross 308 broilers (age, 35 d; carcass weight, 1.1 kg) from conventional farm (RCF, n = 60) and animal welfare farms (RAWF, n = 60) were analyzed. Proximate composition, pH, color (lightness, redness, and yellowness), water-holding capacity (WHC), shear force, total aerobic bacteria (TAB), and volatile basic nitrogen (VBN) were measured and the levels of bioactive compounds such as dipeptides (anserine and carnosine), creatine, creatinine, and their anti-oxidation activity were determined. RESULTS: The RCF and RAWF did not differ significantly in their proximate composition, WHC, color, and creatine and carnosine levels. The pH value was significantly lower in RAWF than in RCF on day 7. The shear force value was significantly higher in RAWF than in RCF throughout the storage duration. TAB in RCF on day 9 were significantly higher than those in RAWF. The VBN content of RAWF was significantly lower than that of RCF after 5 days of storage. Creatinine content was significantly higher in RAWF (3.50 mg/100 g) than in RCF (3.08 mg/100 g) on day 1. Along with higher carnosine and anserine contents of RAWF, it had significantly higher 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) radical scavenging activities than those of RCF. CONCLUSION: These results imply that the animal welfare farming system beneficially affects the overall oxidative stability of Ross 308 thigh meat.
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The physicochemical characteristics and flavor-related compounds of thigh meat derived from diverse Korean native chickens (KNC), namely Hanhyup No. 3 (HH3), Woorimatdag No 1 (WRMD 1), and Woorimatdag No 2 (WRMD 2), under fresh and frozen-thawed conditions were studied and compared with those of commercial broilers (CB). Regardless of the breed, KNC showed a higher (p < 0.05) percentage of linoleic and arachidonic acid. The highest proportion of docosahexaenoic acid was observed in WRMD 2. Despite having a higher collagen content, thigh meat derived from KNC maintained a similar texture profile in comparison to that of CB. The concentrations of most free amino acids (FAA), except for taurine, tryptophan, and carnosine, were higher in frozen-thawed meat than in fresh meat. Regarding volatile organic compounds (VOC), following freezing, the concentration of favorable VOCs increased in CB, but decreased in WRMD 1, suggesting a loss of pleasant flavor in frozen-thawed meat. This study indicated that changes in VOCs, including hydrocarbons (d-limonene, heptadecane, hexadecane, naphthalene, pentadecane, 3-methyl-, tridecane), esters (arsenous acid, tris(trimethylsilyl) ester, decanoic acid, ethyl ester, hexadecanoic acid, ethyl ester), alcohol (1-hexanol, 2-ethyl-), ketones (5,9-undecadien-2-one, 6,10-dimethyl-), and aldehydes (pentadecanal-, tetradecanal, tridecanal), may be a promising marker for distinguishing between fresh and frozen-thawed chicken thigh meat. These findings are of critical importance as preliminary data for developing high-quality chicken meat products.
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The effect of marination with black currant juice (BCJ) was investigated for their effects on meat quality and content of biogenic amines (BAs) [putrescine (PUT), cadaverine (CAD), histamine (HIM), tyramine (TYM), and spermidine (SPD)] in pork belly during storage at 9°C. BCJ was shown to have antibacterial activities against Escherichia coli and Pseudomonas aeruginosa. Additionally, the pH of pork belly marinated with BCJ (PBB) was significantly lower than that of raw pork belly (RPB) during storage. No significant difference in microorganisms between RPB and PBB was observed at day 0 of storage. However, at days 5 and 10 of storage, volatile basic nitrogen (VBN) was significantly decreased in PBB compared to RPB, and PBB also demonstrated significantly lower numbers of bacteria associated with spoilage (Enterobacteriaceae and Pseudomonas spp.) at these time-points. PBB was also associated with significantly reduced formation of BAs (PUT, CAD, TYM, and total BAs) compared to RPB at days 5 and 10 of storage. These results indicated that BCJ can be regarded as a natural additive for improving meat quality by preventing increased pH, VBN, bacterial spoilage, and inhibiting BAs formation during refrigerated storage.
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The super-hydrophobic surface can be used in anti-pollution, self-cleaning, and anti-corrosive properties. Two-step surface treatment process on Al-coated glass was conducted by surface etching using potassium hydroxide (KOH) and surface coating using lauric acid for super-hydrophobic surface. The KOH-etched Al surface (1st etching) was changed to a hydrophilic property with a water contact angle (WCA) of 68° to 48°. On the other hand, the WCA of the etched Al surface was changed to about 153° with super-hydrophobic property when the lauric acid coating (2nd coating) was applied on the KOH-etched Al surface for 30 minutes. We found that the hydrophobicity of Al surface was related to the roughness by surface modification as well as the Al film thickness by sputtering method.