Premium
Relationships between the back‐scatter of polarised light and the fibre‐optic detection of connective tissue fluorescence in beef
Author(s) -
Swatland H J
Publication year - 1997
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199709)75:1<45::aid-jsfa839>3.0.co;2-h
Subject(s) - fluorescence , myoglobin , absorbance , connective tissue , fluorescence spectroscopy , analytical chemistry (journal) , chemistry , materials science , wavelength , nuclear magnetic resonance , optics , pathology , optoelectronics , physics , medicine , chromatography , organic chemistry
The back‐scatter of light (400–800 nm) from bovine m longissimus lumborum ( n =47) was measured with a fibre‐optic probe fitted with crossed polarisers to exclude Fresnel reflectance. Unlike normal fibre‐optic spectra (which may be relatively flat), back‐scatter was approximately proportional to wavelength, being low at 400 nm and high at 800 nm. The shape of the spectrum was modified by myoglobin absorbance, with a Soret minimum at 430 nm. Connective tissue fluorescence (365 nm excitation, 400–550 nm emission) was measured through a single optical fibre moving down the longitudinal axis of the muscle. Back‐scatter at 430 nm was correlated positively with minimum fluorescence ( r =0·73, P <0·001), the area under the fluorescence signal cm −1 ( r =0·81, P <0·001) and fluorescence peaks cm −1 ( r =0·46, P <0·005). Back‐scatter at 800 nm was correlated weakly and negatively with minimum fluorescence ( r =‐0·28, P <0·05) and peaks cm −1 ( r =‐0·26, P <0·05). Thus, in the probe detection of connective tissue fluorescence in meat, errors caused by differences in myoglobin concentration may exceed those caused by differences in pH‐related light scattering. © 1997 SCI.