Characterization of visible spectral intensity variations of wholesome and unwholesome chicken meats with two-dimensional correlation spectroscopy

Generalized two-dimensional (2D) correlation analysis of visible spectra (400-700 nm) was performed to characterize the spectral intensity variations of wholesome and five different classes of unwholesome chicken meats. The meats were obtained from the chicken carcasses that were judged to be wholesome or condemned by a Food Safety and Inspection Service (FSIS) veterinarian at a poultry processing plant. The unwholesome carcasses were condemned either because they were improperly bled (cadaver) or showed a disease symptom such as air-sacculitis, ascites, septicemia, or tumors. The results showed that there are at least three prominent bands around 445, 485, and 560 nm that could be attributed to deoxymyoglobin, metmyoglobin, and oxymyoglobin absorption, respectively. The results also demonstrated that deoxymyoglobin, metmyoglobin, and oxymyoglobin components coexist in all meats. There is, however, a clear indication that there were more variations in oxymyoglobin and deoxymyoglobin and less variations in metmyoglobin in the wholesome and cadaver meats than in the diseased meats. The asynchronous spectral analysis of the wholesome and unwholesome meats revealed that the spectral intensity change at the 485 nm band occurs later than those of the 445 and 560 nm bands. It indicates that metmyoglobin, the degraded species of both the deoxymyoglobin and oxymyoglobin, mainly existed in the diseased meats.