Industrially prepared fish fillets analyzed by IR spectroscopy for species authentication and discrimination between fresh and frozen-thawed samples are reported in Table 1. Samples were ob- tained by different producers. Fresh fillets were stored in ice inside a cold room (4 C) until the analyses, for a maximum of two days. The frozen fillets were stored at 18 C up to two months and before analyses they were thawed at 4 C for 48 h.