Rafael H. Carvalho

Underlying connections between the redox system imbalance, protein oxidation and impaired quality traits in pale, soft and exudative (PSE) poultry meat.

The connections between the redox imbalance in post-mortem muscle, early protein oxidation and the onset of pale, soft and exudative (PSE) condition in chicken breast are studied. PSE was induced by incubation of post-mortem chicken carcasses at 37°C for 200min. PSE-induced muscle consistently had faster pH decline and lower pH at 200min (5.84 vs. 6.59) and 24h (5.69 vs. 5.96), higher L(∗) (54.4 vs. 57.3), and lower texture and water holding capacity (WHC) than normal meat. The activities of catalase, glutathione peroxidase and superoxide dismutase were significantly lower in PSE-induced samples than in the normal counterparts. PSE was more susceptible to proteolysis and protein oxidation than normal meat during succeeding chilled storage with more intense tryptophan and thiols depletion, higher protein carbonylation and more intense formation of protein cross-links. We provide plausible explanations to support the role of protein oxidation in the impaired quality PSE chicken.

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.

Lipid and protein oxidation in charqui meat and jerked beef

In this study, the changes in the lipid (Lox) and protein oxidation (Pox) were measured quantitatively by TBARS and carbonyl methods, respectively, throughout the salting and drying steps of charqui meat (CH) and jerked beef (JB) preparation and their storage up to 60 days. The experiment was carried out on CH samples treated with brine (20.0%) and JB with same brine solution added with sodium nitrite (0.02%). After 60 days of storage, the carbonyl substances in CH were 2.77nmol mg-1 while in the JB samples, there was 61.0% oxidation inhibition. The TBARS determination revealed a Lox inhibition by approximately 5-fold in the latter samples. These results indicated that in the metmyoglobin molecule, the nitrite kept the Fe in the Fe2+ state in JB samples whereas in CH, the Fe was oxidized to Fe3+, which catalyzed the oxidation reactions more efficiently, leading to the higher development of Lox and Pox.

Poultry Meat Color and Oxidation

Abstract Poultry and poultry products remain one of the most popular and consumed muscle foods worldwide. Increasing awareness and concern of consumers about meat origin, animal well-being, and meat safety challenges the meat industry and scientific community to produce poultry meat of the utmost quality. Oxidation of muscle components and discoloration are major threats to poultry meat quality as they may be responsible for consumer rejection and hence, economical losses. The recent advances in methodological approaches and scientific knowledge enables a deeper comprehension of the mechanisms of lipid, protein, and myoglobin oxidation in poultry systems and the influence of these reactions on poultry quality. This chapter will cover novel aspects of the biochemical basis of poultry color and oxidation, the deterioration of poultry during storage and processing as a result of oxidative reactions, and means of antioxidant protection of poultry. For each of the aforementioned topics, assorted poultry species will be considered including (but not limited to) chicken, turkey, goose, and ostrich, among others.

Animal Welfare and Meat Quality: Methodologies to Reduce Pre-slaughter Stress in Broiler Chicken

The aim of this study was to report the causes of stress for commercial chickens during the manoeuvres performed immediately prior to slaughter. The model used to quantitatively measure the stress level of a condition was the occurrence of PSE (pale, soft and exudative) meat in the breast fillet. This abnormal meat condition affects meat quality and has damaging economic consequences for the meat industry. Several initiatives have been taken to alleviate the stressful conditions of commercial chickens. This chapter presents a detailed discussion of the techniques that would diminish, if not abolish, the stress placed on broiler chickens, thereby producing better quality breast fillet meat.