Monitoring phosphate marinade penetration in tumbled chicken filets using a thin-slicing, dye-tracing method

A simple dye-tracing method was developed to monitor the kinetic process of water penetration in chicken filets subjected to rotary tumble marination. A total of 860 chicken breast filets were tumbled for 0, 5, 15, and 30 min in marinades containing 1.6 or 3.2% sodium PP, TPP, or HMP with or without 8% NaCl. Marinade penetration was monitored by tracing a dye (FD&C Blue No. 1) migrating into different layers of the filets using a spectrophotometric measurement (absorbance at 627 nm). Marinades penetrated most rapidly in the initial 5 min, e.g., PP, TPP, and HMP at a low level (1.6%) enhancing the rate of penetration of unsalted water in the first 5 min by 196, 171, and 138%, respectively. However, the effect of phosphates was diminished when their concentration was high (3.2%) or when salt was present. Overall, low-level (1.6%) phosphates facilitated water penetration deep into the filets, whereas high-level (3.2%) phosphates and salt improved water penetration in the surface layers of the filets.