The objective of this work was to investigate the influence of water spray treatment before broiler slaughtering on the quality of breast meat (Pectoralis major) and to observe ultrastructural changes promoted by the biochemical/physiological events during rigor mortis onset. Commercial Ross chickens were divided into two groups: Untreated Group (UG) (n = 608) and Treated Group (TG) (n = 611), without and with water shower treatment, respectively. Drip and cook losses, pH and color measured after 24 h postmortem demonstrated that antemortem water shower treatment inhibited PSE development in chicken breast meat. Histological studies of the PSE samples from UG birds after 72 h postmortem revealed under light microscopy a shrinking of muscle cell diameter by approximately 10% in relation to TG samples and an extracellular enlargement of endomysium and perimysium sheaths. By electron microscopy of PSE meat, Z‐lines appeared fragmented, A‐bands including the M‐line disappeared and a super‐contraction of sarcomeres was observed, indicating that proteins were adversely affected by heat stress.

No abstract