Combination of muscle tension and crust-freeze-air-chilling improved efficacy of air chilling and quality of broiler fillets

Abstract

The objective of this study was to evaluate the effects of water immersion chilling (WIC), air chilling (AC), and crust-freeze-air-chilling (CFAC) on the efficacy of broiler chilling and quality of breast fillets with and without muscle tension (MT), restraining both wings behind the carcass. In each of 3 replications, 66 birds were purchased locally and processed at the Michigan State University meat laboratory. After evisceration, one-half of the birds were subjected to MT and the remaining birds received no MT. Twenty-two birds (11 with and 11 without MT) per chilling were randomly assigned to WIC (ice/water slurry at 0.2°C), AC (air at 1°C/1.5 m/s), or CFAC (air at -12°C/1.5 m/s). After chilling and aging for 3 h postmortem (PM), all breast fillets were deboned, one-half of which were immediately quick-frozen or cooked, whereas the remaining half were further aged on ice for 24 h PM. All left fillets were used for pH, R-value, and sarcomere measurements, whereas all right fillets were used for shear force. During chilling, breast temperature was reduced from 40 to 4°C in an average of 62, 68, and 140 min for WIC, CFAC, and AC, respectively. The birds at 3 h PM had higher pH and shear force than those of birds at 24 h PM except the CFAC with no MT (P < 0.05). Breast fillets with MT showed lower shear force than the fillets without MT at 24 h PM (P < 0.05) in AC and CFAC. Based on these findings, the combination of CFAC and MT appears to improve both air chilling efficacy and breast fillet quality.