Influence of grilling pretreatment and optimization of sous vide processing parameters on the physicochemical and microbiological quality of pirarucu fillet.

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 ℃/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 ℃ for 568.8 s were the best sous vide parameters obtained, with highest water-holding capacity (%) 93.60, texture (N) 6.24, ΔE* 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.