Monitoring changes in whiting (Merlangius merlangus) fillets stored under modified atmosphere packaging by front face fluorescence spectroscopy and instrumental techniques.

Quality assessment of whiting (Merlangius merlangus) fillets stored in normal air (control group) and modified atmosphere packaging (MAP1: 50% N2/50% CO2 and MAP2: 80% N2/20% CO2) for up to 15 days at 4 °C was performed. The physico-chemical [pH, drip loss, moisture content, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS) and peroxide value (PV)], textural (i.e., hardness, fragility, gumminess, chewiness, springiness, cohesiveness), and color (i.e., L(∗), a(∗), b(∗)) parameters were determined. Front face fluorescence spectroscopy (FFFS) emission spectra were also scanned on the same samples with excitation set at 290 and 360 nm. The results indicated that MAP treatment, particularly MAP1 had an obvious preservative effect on fish quality by reducing pH value, TBARS and TVB-N contents, and retarding the softening of fish texture compared to control samples. Principal component analysis (PCA) applied to physico-chemical and instrumental data sets showed a clear discrimination of fish samples according to both their storage time and condition. A complete (100%) of correct classification was obtained by the concatenation of spectral, physico-chemical, and instrumental data sets. The results demonstrated that storage under MAP can be recommended to improve quality of whiting fillets, which in turn, can be evaluated by FFFS as a rapid and non-destructive technique.