Subcutaneous Fat Thickness Measurement by Raman Spectroscopy

Since the fat content of pork is a deciding factor in grading the quality of meat, the use of a noninvasive subcutaneous probe for real-time, in situ monitoring of the fat components is of importance to vendors and other interested parties. Fortunately, in situ, in vivo monitoring of subcutaneous fat can be accomplished with spatially offset Raman spectroscopy (SORS) using a fiber-optic probe. The probe acquires Raman spectra as a function of spatial offset. These spectra are used to determine the relative composition of fat-to-skin. The Raman intensity ratio varies disproportionately depending on the fat content, with variations in slope that are correlated to the thickness of the fat layer. Ordinary least square (OLS) regression using two components indicates that depth-resolved SORS spectra reflect the relative thickness of the fat layer.