Autofluorescence spectra as related to tensile properties for perimysium from bovine masseter

Dissected, raw and heated (70 degrees C) perimysial sheets (74) from bovine masseter were subjected to fluorescence spectroscopy and tensile testing. The sheets were excited at 280 nm and 335 nm. Fluorescence measurements correlated (R = 0.62-0.93) with various tensile parameters. For raw samples, excitation at 280 nm predicted the breaking force with slightly reduced precision, 0.31 N vs 0.29 N, compared to excitation at 335 nm. The correlation between tensile parameters and the fluorescence spectrum was diminished after heat treatment (Rmax = 0.71 compared to Rmax = 0.93 for the unheated system). The lower predictability for heated systems was due to nonlinearity as well as lack of precision in the tensile method for weak tissues.