Article Influence of grilling pretreatment and optimization of sous vide processing parameters on the physicochemical and microbiological quality of pirarucu fillet Enrique PinoHerna ´ndez 1,2,3 , Wanessa Almeida da Costa 4 , Eder A Furtado Araujo 1 , Pedro M Villa 5 , Lu ´cia de F Henriques Lourenc ¸o 1 and Raul de Carvalho Junior 4 Abstract The demand for high-quality food products has promoted the study of techniques for its processing and conservation. The present research aimed to evaluate the influence of grilling pretreatment on the physical characteristics of pirarucu fillets and the heat transfer process by a computational modelling, and to optimize the sous vide process parameters. Before and after the sous vide process, the samples were analysed for microbiological, chemical and physical characteristics. There was no significant difference between the total experimental time of grilling and that obtained by computational modelling. Immersion in brine for 300 s in combination with grilling at 200  C/120 s was selected because of its water-holding capacity (%) 79.40  0.31, texture (N) 1.91  0.40 and value of L* 74.44  0.38 in the fillets. Cooking at 60  C for 568.8 s were the best sous vide parameters obtained, with highest water-holding capacity (%) 93.60, texture (N) 6.24, ÁE* 7.43, and with microbiological loads below 6 log CFU/g and 7 log MPN/g in the final product. Useful information obtained from this study highlighted the brine and grill pretreatment in combination with sous vide proved it is a potential solution for developing pirarucu products even at an industrial scale. Keywords Brine, thermal process, grill, Arapaima gigas, vacuum-packaged, sous vide, response surface methodology Date received: 19 August 2019; accepted: 25 May 2020 INTRODUCTION The pirarucu (Arapaima gigas) is the largest freshwater fish in the world that reaches up 2–3 m and 200 kg. This fish inhabits the Amazon River Basin in South America and it is considered as one of the most important com- mercial fish species in this region, which has also been well reproduced in captivity (Cortegano et al., 2017). The pirarucu is traditionally preserved and consumed in natura or dry-salted without a good standardized pro- cessing method that guarantees its quality and preservation (Pino-Herna´ndez et al., 2020). For this reason, it is essential to assess other processing methods that increase the feasibility of introducing the fish into niche markets as a value-added processed product. 1 LAPOA/FEA (Faculty of Food Engineering), Federal University of Para, Guama ´, Bele ´m, Para ´, Brazil 2 CEB/Center of Biological Engineering, University of Minho, Braga, Portugal 3 INYCIA Research Group, Sefitrones, Cartagena, Bolivar, Colombia 4 LABEX/FEA (Faculty of Food Engineering), Federal University of Para, Guama ´, Bele ´m, Para ´, Brazil 5 Foundation for the Conservation of Biodiversity, Estado Amazonas, Venezuela Corresponding author: Enrique Pino–Herna ´ndez, University of Minho, Gualtar Campus, Braga 4710-057, Portugal. Email: eph@ceb.uminho.pt Food Science and Technology International 27(1) 84–96 ! The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1082013220934257 journals.sagepub.com/home/fst