The thermal effects on chicken white muscle cooked under reduced pressure were evaluated by observing the color and firmness in relation to the proton relaxation behavior.
The lightness and greenness increased with increasing temperature, while the yellowness fluctuated widely and randomly. This color behavior matched well with the change in firmness, which increased markedly after cooking at above 40°C. The uniphase to bi-phase shift of the spin-spin proton relaxation curve at around 50°C indicated marked changes in the protein structure at around 40°C and up to 50°C. This behavior was also observed after using other cooking methods.