This study investigated the effects of high hydrostatic pressure (HHP) and ultraviolet radiation (UV-C), individually and combined, on the physical, chemical and bacterial parameters of Nile tilapia (Oreochromis niloticus) fillets stored at 4 °C for 14 days. Tilapia fillets were divided into four groups: control (untreated samples), UV-C, HHP, and UV-C combined with HHP (UV-C+HHP); UV-C was applied at dose of 0.103 ± 0.002 J/cm2, and HHP at a pressure of 220 MPa for 10 min at 25 °C. All samples were analyzed for total aerobic mesophilic count (TAMC), total aerobic psychrotrophic count (TAPC), Enterobacteriaceae count, pH, lipid oxidation, total volatile basic nitrogen (TVB-N), ammonia (NH3), and biogenic amines. Although UV-C accelerated (P ≤ 0.05) the formation of cadaverine, both UV-C and HHP, alone or together, retarded bacterial growth and delayed the increase (P ≤ 0.05) in pH, TVB-N, NH3 and biogenic amines during refrigerated storage, extending the shelf life of refrigerated tilapia fillets at least 2.5 times considering the TAMC counts. Lipid oxidation was unaffected (P > 0.05) by UV-C radiation, and decreased (P ≤ 0.05) by HHP and UV-C+HHP. HHP alone or combined with UV-C showed higher potential benefits for tilapia fillets preservation considering the positive influence on cadaverine levels and lipid oxidation.
Bibliographical noteFunding Information:
The authors are thankful for the financial support provided by the Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), grant numbers E-26/111.673/2013; E-26/010.001954/2014; E-26/201.185/2014; E-26/110.094/2014; E-26/010.001961/2014; E-26/010.001911/2014; E-26/101.403/2014; E-26/202.305/2017, and E-26/202.306/2017 as well as the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) grant numbers 311361/2013-7, 401922/2013-8, 313917/2013-2, 442102/2014-3, 441987/2014-1, and 150696/2017-5; the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), grant number E-26/101.403/2014 (CAPES/FAPERJ E-45 - PAPDRJ/2013), and the William Ferreira Leal Junior from Embrapa Food Technology for aiding in the pressurization process.
© 2018 The Author(s).
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