| Abstrakt: |
Reflectance spectra of the longissimusmuscle from pork loins of three qualities (PSE, normal, and DFD) covering the wavelengths 450 to 810 nm were recorded. With 300 spectral data points, computer analysis of the data identified two wavelengths 633 and 627 nm, at which the correlation was highest between the reflectance (log 1/R) of the longissimusand optical density (OD) (log 1/T) of the Hart extract. The pork quality index (PQI) equation derived for predicting the OD of the Hart extract is based on the logarithmic difference between the reflectance values at 633 and 627 nm. The numerical value from the PQI equation is consistent with the numerical scores associated with the Wisconsin Pork Quality Standards (WPQS). Correlation of PQI values with OD (log 1/T) of the Hart extract and subjective quality scores (WPQS) yielded r values of .86 and .80, respectively. Average reflectance values of six chops within each of the three quality groups (PSE, normal, and DFD) were .819, .700 and .588, respectively, at 633 nm relative to a white vitrolite reflectance standard. |
