Development of a new salmon salting-smoking method and process monitoring by impedance spectroscopy

In this work two objectives were proposed: (i) to optimize a new salmon salting-smoking method using vacuum packaging and (ii) to evaluate the application of impedance spectroscopy (IS) to the on-line monitoring of the process. Different processing conditions were evaluated (4 smoke flavoring (SF) salt concentrations, 3 salting times, salting in vacuum or in air). Physico-chemical analyses and IS measurements were performed with three different sensors during the process. Salting with 16 g SF salt/100 g fish in vacuum packaging provided smoked salmon similar to products currently available on the market. This new method has the advantages of reducing processing times and waste. IS measurements were carried out by three different electrodes. The most appropriate sensor for process monitoring was a needle electrode, with which robust prediction models for NaCl content, moisture and aw during the salting-smoking process were obtained. The results showed the potential of IS as a rapid on-line monitoring method of the salmon salting-smoking process.

► A new salting-smoking method for salmon using vacuum packaging was developed. ► Impedance spectroscopy was studied in the monitoring of the smoking process. ► Vacuum packaging speeded up the process of NaCl absorption and salmon dehydration. ► The needle electrode was the most appropriate for smoking process monitoring. ► Impedance spectroscopy was a rapid monitoring method for the salmon smoking process.