ABSTRACT The present study was carried out to investigate the influence of freezing-thawing cycles (0, 2, 4 and 6) on lipid oxidation and myowater contents and distribution. Nine replicates of chicken breast meat samples were used for each cycle. Lipid oxidation was determined by measuring peroxide value, and malondialdehyde (MDA) concentrations, which reflect thiobarbituric acid reactive substance (TBARS). Color was determined with a digital colorimeter. Muscle moisture contents were determined by drip loss and thawing loss, water holding capacity, and nuclear magnetic resonance (NMR). The results showed that, as the number of freeze-thaw cycles increased, meat redness decreased and MDA and peroxide values increased. Drip loss and thawing loss tended to decreasing as the number of freeze-thaw cycles increased. Water holding capacity also decreased as a function of increasing freeze-thaw cycles. NMR relaxometry profile showed freeze-thaw cycles change the water distribution of meat subjected to multiple freeze-thaw cycles. In conclusion, multiple freezing and thawing rate (6 cycles) increased lipid oxidation, decreased myowater, and impaired the color of chicken meat.

Marigold flower extract, a natural pigment, was used to determine its effect on carcass and skin pigmentation, immunity and growth performance of broiler chickens. Two hundred and forty 1-day-old Arbor Acres broiler chicks were randomly distributed into four treatment groups with six replicates in a randomized block design. Birds were fed basal diet for 42 d with or without supplementation of marigold flower extract at various concentrations, i.e., 0 (MG0, control), 100 (MG100), 150 (MG150) and 200 (MG200) mg/kg of feed, respectively. Feed intake and live body weight were weekly recorded. Carcass and shank color, and antibody titers against Newcastle and Influenza viruses were measured. Results showed that marigold flower extract significantly (p<0.05) improved live body weight and relative thymus weight. However, feed intake, feed conversion ratio (FCR), and spleen and bursa weights were not significantly affected. Yellowness (b*) of breast and thigh muscles increased by the dietary supplementation of marigold flower extract compared with the control diet. However, lightness (L*), redness (a*) and redness to yellowness ratio (a/b) were not influenced by the treatments. Moreover, Roche color fan scores of the shank skin were increased at market age (d 42). The results revealed that marigold extract enhanced antibody titers against Newcastle and influenza viruses. It was possible to conclude that the dietary supplementation with marigold flower extract at the rate of 200 mg/kg of feed enhanced carcass and shank color, antibody titers against ND and AI, and growth performance of broiler chickens.

Sixteen polycyclic aromatic hydrocarbons (PAH) were measured in total suspended particulate matter (TSPM) samples collected at an urban and industrial cum residential site in Agra (India) from December 2005 to December 2006. The average total PAH concentration was found to be 115 ± 17 ng m-3. The measured concentrations were found to be lower than those reported from other cities in India like Chennai, Delhi, Kanpur, Mumbai and Kolkata. The mass distribution in air was dominated by high molecular weight compounds. PAH concentration showed a significant seasonal cycle during the year with greater concentration during the cold months due to changes in emission sources and meteorological factors. The presence of specific tracers and calculation of characteristic molecular diagnostic ratios revealed vehicular exhausts and emissions from coal and biofuel combustion as the major sources of these compounds.

Se determinaron 16 hidrocarburos aromáticos policíclicos (HAP) en muestras de partículas suspendidas totales de un sitio urbano industrial y residencial en Agra (India), de diciembre de 2005 a diciembre de 2006. El promedio de la concentración total de HAP fue de 115 ± 17 ng m-3. Se encontró que las concentraciones determinadas son menores que las reportadas para otras ciudades de la India como Chennai, Delhi, Kanpur, Mumbai y Kolkata. La distribución de masa en el aire estuvo dominada por los compuestos de peso molecular alto. Las concentraciones de HAP mostraron un ciclo estacional anual significativo con concentraciones elevadas durante los meses fríos debido a cambios en las fuentes de emisión y a factores meteorológicos. La presencia de trazadores específicos y el cálculo de tasas moleculares características reveló que los gases vehiculares y las emisiones por la combustión de carbón y biocombustibles son las principales fuentes de esos compuestos.