Adriana Lourenço Soares

Broiler transportation conditions in a Brazilian commercial line and the occurrence of breast PSE (Pale, Soft, Exudative) meat and DFD-like (Dark, Firm, Dry) meat

The objective of this work was to investigate the effect of road transportation conditions on the occurrence of broiler PSE-(Pale, Soft, Exudative) and DFD-like (Dark, Firm, Dry) meats in the Brazilian commercial slaughterhouse plant. Samples of Pectoralis major m from 47-day-old broilers of commercial lineage were analyzed. The results indicated that water-bathing birds just before journey over 3.0km promoted the occurrence of 46.0% of PSE and 4.0% of DFD-like meat, while birds under non-water bathing conditions presented 14.7 and 2.0%, respectively. For a distance of 68.0km, the occurrences of PSE-and DFD-like meat were 44.0 and 0.0% under water bathing conditions, and 52.0 and 0.0% without water bathing, respectively. Water bathing at the farm was a critical manoeuvre for increasing the unfavourable truck microenvironment for short journey, whereas conversely for longer journey it was less stressful influencing the broiler breast meat quality.

Prediction of chicken quality attributes by near infrared spectroscopy

In the present study, near-infrared (NIR) reflectance was tested as a potential technique to predict quality attributes of chicken breast (Pectoralis major). Spectra in the wavelengths between 400 and 2500nm were analysed using principal component analysis (PCA) and quality attributes were predicted using partial least-squares regression (PLSR). PCA performed on NIR dataset revealed the influence of muscle reflectance (L(∗)) influencing the spectra. PCA was not successful to completely discriminate between pale, soft and exudative (PSE) and pale-only muscles. High-quality PLSR were obtained for L(∗) and pH models predicted individually (R(2)CV of 0.91 and 0.81, and SECV of 1.99 and 0.07, respectively). Water-holding capacity was the most challenging attribute to determine (R(2)CV of 0.70 and SECV of 2.40%). Sample mincing and different spectra pre-treatments were not necessary to maximise the predictive performance of models. Results suggest that NIR spectroscopy can become useful tool for quality assessment of chicken meat.

The effect of management of transport and lairage conditions on broiler chicken breast meat quality and DOA (Death on Arrival)

The aim of this work was to evaluate the influence of time of broiler chicken transportation and laira ge prior to slaughtering on the occurrence of PSE (Pale, Soft, Exudative) meat and Death On Arrival (DOA) under no ncommercial conditions in the Brazilian summer. Male birds (n=250) from a commercial line were subjecte d to different periods of journey (30, 90, and 180 min) and lairage (0, 90, and 180 min) before slaughterin g. The occurrence of PSE was higher in broilers subjected to shorter journeys and lairage periods, whereas DO A was more pronounced upon longer periods of transport an d lairage. The DOA occurrence percentage was much h in comparison to commercially available figures, co nfirming that broiler chickens are very sensitive tboth transport and lairage maneuvers.

Lipid oxidation and fatty acid profile related to broiler breast meat color abnormalities

The aim of this work was to study the influence of lipid oxidation on broiler breast meat (Pectoralis major m) color abnormalities. There were 27.0 % more lipid oxidation in PSE in relation to normal meat and 41.0 % more in relation to DFD-like meat (p<0.05). The fatty acid profile was also significantly different since the arachidonic acid (AA) fraction increased 38.6 and 70.5 % in PSE meat comparing to normal and DFD-like meats, respectively. The ratio PUFA/SFA changed in these three types of meat: 0.736, 0.713 and 0.694 for PSE, normal and DFD-like meat respectively, reflecting the highest production of polyunsaturated fatty acids in the PSE meat samples. Results indicated that phospholipase A2 enzyme activities played a relevant role towards the development of PSE-meat syndrome in a cascade of biochemical reactions promoting the formation of free radicals from AA, which ultimately damaged the muscle membrane systems.

Functional properties of PSE (Pale, Soft, Exudative) broiler meat in the production of mortadella

Este trabalho foi realizado para avaliar o efeito dos fatores que conduzem a formacao das carnes PSE (Pale, Soft, Exudative) sobre as propriedades funcionais da carne de frango. Carnes PSE foram caracterizadas pelos valores de pH e L* e as formulacoes da mortadela consistiram de proteina isolada de soja, trifosfato de sodio, amido de mandioca e a adicao das carnes normal e PSE. A funcionalidade da carne foi avaliada medindo a capacidade de retencao de agua (CRA), perfil de textura, estabilidade de emulsao (EE), e cor dos produtos finais. Os resultados mostraram que na mortadela preparada com carnes PSE, as proteinas desnaturadas afetaram a EE. Aditivos sao necessarios para potencializar as propriedades funcionais da carne PSE.

Carnes PSE (Pale, Soft, Exudative) e DFD (Dark, Firm, Dry) em lombo suíno numa linha de abate industrial

The needs of higher production of low fat pork have conducted changes on the muscle biochemical characteristics leading to color abnormality producing so-called PSE and DFD meats. The consequence is a relevant economical loss due to the impairment of meat functional properties. In this experiment, 946 samples of Longissimus dorsi m. from barrows and gilts of Dalland lineage, of 100 days of age, were evaluated in a pork abattoir located in the south of Brazil. Samples were classified based on the L*24 h e pH24 h values. Results showed the occurrence of 22.8% of PSE meat, 1.0% de DFD meat and 76.2% of normal meat. These relatively higher values for PSE show undoubtedly the needs to carry out pre- and post-mortem management in order to maintain meat quality thus avoiding the excessive economic cost due to these meat abnormalities.

Synergism between dietary vitamin E and exogenous phytic acid in prevention of warmed-over flavour development in chicken breast meat, Pectoralis major M.

O efeito da suplementacao de acetato a-tocoferol (AT) e a aplicacao exogena desta vitamina E associada com acido fitico (AP) foi avaliado no desenvolvimento do WOF em file de peito de frango. O grupo controle foi alimentado com 7,7IU de AT/kg de racao e o grupo suplementado foi alimentado com 200IU de AT/kg de racao. A vitamina E na dieta inibiu o desenvolvimento de WOF, medido atraves do TBARS, em 78,9; 69,0; 60,7 e 46,5% (p<0,05) durante armazenamento a 6oC durante 0, 1,3 e 5 dias respectivamente. Esta inibicao foi significativamente aumentada (p<0,05) em 86,1; 91,6; 92,9 e 95,3% armazenamento a 6oC durante 0, 1,3 e 5 dias respectivamente, quando 2mM de PA foi adicionado no file de peito de frango suplementado. Atraves da Metodologia de Superficie de Resposta, no experimento exogeno, foi observado que o AT parece nao ter um papel significante em relacao a inibicao da oxidacao, enquanto que AP inibe parcialmente nas amostras armazenadas a 6oC durante 48h. Esses resultados mostram que AT na dieta inibiria na iniciacao e subsequentemente AP atuaria na propagacao, ocorrendo uma reacao sinergica entre os dois antioxidantes.

Improving transport container design to reduce broiler chicken PSE (pale, soft, exudative) meat in Brazil

Throughout the chicken production chain, transport from farm to the commercial abattoir is one of the most critical sources of stress, particularly heat stress. The aim of this work was to describe the performance of a new prototype truck container designed to improve the microenvironment and reduce the incidence of pale, soft and exudative (PSE) meat and dead on arrival (DOA) occurrences. Experiments were carried out for four different conditions: regular and prototype truck, both with and without wetting loaded cages at the farm (for bird thermal stress relief) just before transporting. While there was no difference in the DOA index (P ≥ 0.05), the prototype truck caused a reduction (P < 0.05) in the occurrence of PSE meat by 66.3% and 49.6% with and without wetting, respectively. The results of this experiment clearly revealed a low-cost solution for transporting chickens that yields better animal welfare conditions and improves meat quality.

Avaliação da atividade antioxidante do ácido fítico de germe de milho

The obtained corn germ phytic acid (CGPA) antioxidant potential was evaluated through the deoxyribose, bathophenanthroline (BPS) and DPPH• assays. In the concentration of 130.5 μM of CGPA the hydroxyl radical maximum sequestering antioxidant activity was 29.3% while standard phytic acid (SPA) presented this maximum activity of 18.2% in the concentration of 33.2 μM of SPA. The BPS assays revealed that the chelation activity towards Fe2+ increased concurrently with the increase of CGPA concentration and its Fe2+ contact time. Finally, DPPH• assay showed that CGPA and SPA did not present electron-donating capacity to DPPH•.

Broiler Chicken PSE (Pale, Soft, Exudative) Meat and Water Release during Chicken Carcass Thawing and Brazilian Legislation

The objective of this work was to investigate the relationship between poultry PSE meat and water loss of frozen chicken carcass in two experiments. The first experiment was carried out in commercial abattoir. Poultry carcass were classified as PSE meat (n=59) (pH 5.8). Water absorption and drip test were performed according to the Brazilian legislation methodologies. The second experiment was carried out with commercial whole five brands frozen carcasses purchased from the local supermarkets (n=30) and analyzed for pH, water holding capacity (WHC) and drip test. PSE poultry meats absorbed 3.59% of water during the processing similar to the control samples; however, released 0.38% more water during thawing of the carcasses. From these five brands evaluated, three presented drip values above 6.0%. The highest drip value was showed by the brand sample that had pH and WHC values characteristics of PSE meat. It could be postulated that PSE meat phenomenon promoted more water release during thawing leading to a misinterpretation in relation to the Brazilian legislation for water carcass liberation during thawing.