Optical detection of meat spoilage using fluorescence spectroscopy with selective excitation wavelength

The native fluorescence (FL) spectra of muscle foods (meat) stored at 4 °C (refrigerated) and 25 °C (at room temperature) were measured with the selected excitation wavelength of 340 nm as a function of storage time to detect the meat spoilage status. The contributions of the principal biochemical components to the FL spectra were extracted using Multivariate Curve Resolution with Alternating Least-Squares (MCR-ALS). The change of the reduced nicotinamide adenine dinucleotide (NADH) content was found from the measured FL spectra and the MCR-ALS analysis, which reflects the microbial spoilage of muscle foods involved in the metabolic processes. This study presents the possibility that the change of relative content of NADH determined by native FL spectroscopy may be used as a "fingerprint" or criterion for monitoring the spoilage status of muscle foods.