Descriptive sensory and instrumental texture profile analysis of woody breast in marinated chicken

The broiler industry is currently experiencing a muscle anomaly referred to as "woody breast," and the effect of different cooking methods on the marination properties of severe woody breast (SWB) has not yet been reported. This study compared the texture attributes of marinated (injected) normal (NOR) and SWB using a convection oven and a flat-top grill. The objectives were 1) to develop and validate a descriptive texture attribute panel with 6 trained panelists using a 16-point scale and 2) to evaluate the instrumental texture profile analysis (TPA) using a texture analyzer. Sixty-four NOR and SWB were obtained from a commercial facility. Fillet color (L*, a*, b*) and pH were measured before marination. In each of 2 trials, the breast muscles were injected in bulk with 15% brine (0.48 STPP, 0.55% NaCl, final concentration), and marinade retention was determined after 20 minutes. The meat was vacuum packaged, stored at -20°C (7 d sensory; 29 d TPA) and then thawed (4°C, 24 h). Fillets were cooked to 73°C on a flat-top grill (176°C) or in an oven (176°C), and cook loss % was determined. Panelist samples (2 × 2 cm) and TPA samples (4 × 2 cm) were cut into 3 pieces. Color and pH were higher for SWB than NOR fillets (P < 0.05). Marinade retention was 83.21% for NOR meat and 59.23% for SWB meat. The flat-top grill method resulted in higher cook loss than oven (P < 0.05). SWB had higher cook loss when compared to NOR (P < 0.05). Sensory texture descriptors springiness, hardness, denseness, cohesiveness, fracturability, fibrousness, crunchiness, and chewiness were higher for SWB than NOR fillets (P < 0.05). TPA attributes also showed higher values for SWB compared to NOR (P < 0.05). No differences in texture were found between the grill and oven for sensory and TPA attributes. In summary, marinated SWB has significant texture differences when compared to NOR, regardless of cooking method.

Modulation of the electron transfer processes in Au-ZnO nanostructures

Plasmonic nanostructures comprising Au and ZnO nanoparticles synthesized by the spontaneous reduction of HAuCl4 in ethylene glycol were used to assess the possibility of modulating the direction of the electron transfer processes at the interface. One electron UV reduction and visible oxidation of the reversible couple TEMPOL/TEMPOL-H was confirmed by EPR spectroscopy. The apparent quantum yield for TEMPOL-H conversion under continuous wave visible excitation depends on the irradiation wavelength, being 0.57% and 0.27% at 450 ± 12 and 530 ± 12 nm, respectively. These results indicate that both the surface plasmon resonance and the interband transition from the 5d to the 6s level of Au nanoparticles contribute to the visible activity of the nanostructure. In addition, by detecting free electron conduction band electrons in ZnO, after the visible excitation of Au/ZnO nanostructures, we provide direct evidence of the photoexcited electron transfer from gold nanoparticles to ZnO.

Sunflower hulls degradation by co-composting with different nitrogen sources

The decomposition of sunflower hull and its mixtures was examined under mesophilic (M) and thermophilic (T) temperatures during 100 days. Thermophilic conditions were used to define the composting process. Vetch, alfalfa and ammonium nitrate were used as nitrogen co-substrates, in 6 treatments: sunflower hulls alone (C), sunflower hulls plus ammonium nitrate (CN), sunflower hulls plus alfalfa (CA), sunflower hulls plus alfalfa and ammonium nitrate (CAV), sunflower hulls plus vetch (CV), sunflower hulls plus vetch and ammonium nitrate (CVN). Total organic carbon (TOC), oxidizable carbon (OC), dry matter, ashes content, total nitrogen (N), cellulose, hemicellulose, lignin, pH, electrical conductivity and C to N ratio were measured to asses the efficiency of the composting process and to determine the best amendment. Results show that sunflower hulls (Sh) treatment with the organic amendments had a better response than the inorganic ones. This was concluded from the variation in the fiberfractions, the decrease in dry matter and the major decrease in C to N ratio.

[Study of 3 hypervariable loci in a mixed Chilean population]

BACKGROUND

Genetic markers are useful to study evolution parameters in populations and to determine kinship.

AIM

To characterize three short tandem repeat loci in a sample of Chilean subjects and compare them with Caucasian and Hispanic populations.

MATERIAL AND METHODS

Three hundred ninety three unrelated subjects that were sent for genetic studies from courts of justice, were studied. The loci FESFPS, F13A01 and vWA in blood samples, were typified amplifying DNA by polymerase chain reactions.

RESULTS

The three studied loci were highly polymorphic. F13A01 and FESFPS were in Hardy-Weinberg genetic equilibrium. A significant excess of heterozygotes was detected for vWA locus. There were no differences in allele frequencies, according to ethnic origins of last names. Allele frequencies for F13A01 and vWA loci were similar to those of Hispanic populations of Unites States and FESFPS loci was different.

CONCLUSIONS

All three loci had a high efficiency for genetic identification tests according to the estimated a priory exclusion probability.