DESCRIPTIVE STUDY OF REFLECTANCE SPECTRA OF HAKE (MERLUCCIUS AUSTRALIS), SALMON (SALMO SALAR) AND LIGHT AND DARK MUSCLE FROM TUNA (THUNNUS THYNNUS)

ABSTRACT The reflectance spectra of foods constitutes a simple, non‐destructive physical method with potential applications in the industry. Color is the most valued properties for customers when buying fresh fish, so that its characterization is important for setting objective quality criteria that can be easily applied at all levels of the production and distribution chain. In this work the reflectance spectra and CIEL*a*b* coordinates of fresh muscle in hake, salmon and tuna (light and dark muscle) it was described. Hake, salmon and the dark tuna muscle show a zone of the spectrum (between 600 and 740 nm) with no significant (P > 0.05) differences between the reflectance percentages, which may be taken as characteristic of fresh fish muscle. The light tuna muscle shows a plateau between 700 and 740 nm, while the dark muscle presents a further two plateaus between 390 and 440 nm and between 470 and 510 nm. PRACTICAL APPLICATIONS The study of the reflectance spectra of fish is a method with many potential applications in the food industry. Spectrum shape is characteristic of each fish. For this reason, a study of the reflectance spectra of the “fresh meat” of commercially interesting fish species could be of value as tool for characterizing fish and fish products. In each case it will be necessary to identify the characteristic wavelengths or spectral regions that provide the “digital footprint” of the species in question. Its characterization is important for setting objective quality criteria that can be easily applied at all levels of the production and distribution chain.