A Simulation of the Real-Time Shelf Life of Frozen Fish Products in a Bulk System Sale

In this study, the real-time shelf life of frozen fillets of two different types of fish, tuna (<i>Thunnus albacares</i>) and hake (<i>Merluccius hubbsi</i>), was studied, simulating a bulk system sale. A glaze treatment was used on all the samples at the beginning, and during the 60-day storage period, the glaze was reapplied at regular intervals on half of the samples ("glazed"), while the other half was not re-glazed ("control"). To assess the quality changes in the two products, the peroxide value (PV), total volatile basic nitrogen (TVB-N), biogenic amines and volatile composition were determined every twenty days. Our results showed that both the glazed and control products did not exceed the legal limits of 35 mg/100 g of TVB-N and 100 mg/kg of histamine. In the hake fillets, in particular, glazing reduced the alteration phenomena associated with oxidative processes. In contrast, because of the high initial thickness of the glazing layer (20% of the weight of the frozen product), the reapplication of glazing during the storage period did not lead to any significant differences between the glazed and control tuna fillets. In conclusion, the different fishes' compositions affect their conservation after the freezing process, which was improved by means of glazing in the case of the hake fillets.