Pectoralis Muscle Shortening and Rigor Development at Different Locations Within the Broiler Breast

Abstract

Two experiments were conducted to evaluate differences in rigor development that occur as a function of location within the broiler breast muscles, pectoralis major (p. major) and pectoralis minor (p. minor). Three locations were evaluated, corresponding to anterior, middle, and posterior samples taken between the cranial and caudal ends of each muscle. Results of the first experiment indicated that the 1.55-mu sarcomere lengths of hot-boned p. major muscle at the anterior location were significantly shorter than those at the posterior location, which were 1.69 mu. Sarcomere lengths of p. minor were shorter than those of p. major in hot-boned muscles, but longer in those aged intact, indicating a significant muscle x treatment interaction. In the second experiment, the anterior location of hot-boned p. major reached the onset phase of rigor in about 1 h, whereas those at the posterior location required between 2 and 4 h postmortem. Between 1 and 8 h postmortem, sarcomere lengths for the anterior location of p. major were also significantly shorter than lengths in the posterior location, but the differences after 24 h were not significant. Samples at all locations of p. minor reached onset of rigor by 15 to 30 min postmortem, with no locational differences throughout the 24 h period of aging. The results of both experiments generally indicated differences between profiles of rigor development of the two muscles and between samples at different locations of the much larger and more complex p. major.

Effects of Post-mortem Temperature on the Physicochemical Properties of Hot-boned Chicken Breast Muscles

“…R-values for meat at both temperatures at 3 hr PM exceeded 1.2. These results are similar to those of Papa and Fletcher (1988). But R-value was not significantly different between the two storage temperatures (p>0.05).…”

“…As rigor mortis develops, R-value increases. R-value of broiler pectoralis major reaches 0.95-0.97 in 15-30 min PM, and reaches 1.2-1.3 in 2-4 hr PM (Papa and Fletcher, 1988).…”

Tratamentos de pré-resfriamento e resfriamento sobre a qualidade de carne de peito de frango

“…Isso demonstrou que a -12 o C, aves com maior energia disponível no pectoralis major (PM) aos 15min p.m., sofreram maior encurtamento. PAPA & FLETCHER [14] verificaram a susceptibilidade do PM de frango ao encurtamento p.m. e observaram que houve redução na retenção de água e na maciez, quando as amostras foram submetidas a cocção e ao processamento. LOCKER & HAGYARD [12] descreveram que músculos acometidos de cold shortening resultaram em endurecimento da carne bovina após o cozimento.…”

Comparison of Physicochemical Characteristics of Hot-boned Chicken Breast and Leg Muscles during Storage at 20℃

“…This result is consistent with that of Beecher et al (1965), which indicates that red muscles (>40% red fibers) generally have a longer post-rigor sarcomere length than do white muscles (<30% red fibers). Papa and Fletcher (1988) reported that reduced sarcomere lengths resulted in increased shear force in broiler breast muscle.…”