14A-10

G. BUGUEñO¹, A. Chiralt², I. Escriche², J. Moreno¹, and J. A. Serra². (1) Departamento de Agroindustrias, Universidad del Bío-Bío, Casilla 447, Chillán, Chile, (2) Department of Food Technology, Universidad Politécnica de Valencia, Camino de Vera, 14, Valencia, 46022, Spain

Brining processes by using vacuum impregnation have been used successfully in pressed curd and meat products. In these processes, salting time is reduced and, at the same time, a more even salt distribution is reached in the product. In the manufacturing of smoked salmon, a drying-smoking process is carried out by different procedures which could be improved (time shortened and yield increased) by applying vacuum treatments.

In this work, the influence of temperature, and vacuum impregnation treatments on mass transfer rate (water and solute) of the tissue was analyzed.

Salt diffusion coefficient in the salmon liquid phase as well as total mass, water, and salt fluxes were determined. Brine immersion (BI) and brine vacuum impregnation (BVI) were carried out in saturated NaCl solutions at 5, 15 and 25 °C. At different times of brining, salmon fillets were analyzed as to weight loss, moisture and salt content, and water activity.

Values of the effective diffusivity coefficient of salt were higher in BVI processes than in BI and less temperature-dependent. This is expected because there is a more effective mass transfer in the tissue pores due to higher pressure differences. Through kinetic studies, and assuming a_w should be the same as in commercial products, it was possible to identify processing times: 50 min in BVI and 80 min in BI. At this a_w value, BVI salmon showed 2% weight loss, while BI samples had 3%, due to the greater ratio salt-gain/water-loss achieved in BVI process.

So, BVI can be recommended in brining-smoking salmon as processing time is shortened and the product retains more water and weight.