Characterizing beef muscles with optical scattering and absorption coefficients in VIS-NIR region

We developed a fiber optical probe to measure spatially resolved diffuse reflectance from beef samples in VIS-NIR bandwidth of 450–950 nm. The optical scattering and absorption coefficients were obtained by fitting the measurements with diffuse equation. Beef absorption coefficients are related to the sample chemical compositions such as the concentration of myoglobin and its derivatives; while scattering coefficients depend on meat structural properties such as sarcomere length and collagen concentration. Structural properties are also key factors in determining beef tenderness, therefore we hypothesize that a correlation exists between optical scattering and cooked Warner–Bratzler shear (WBS) force. Thirty-two, unfrozen beef muscle samples obtained from different animals were used in the correlation study. We found a higher scattering coefficient was associated with a higher cooked WBS. A linear regression analysis showed that sample scattering coefficients were significantly (p < 0.0001) correlated to the corresponding WBS with a coefficient of determination (R2) of 0.59.