51A-15

R. SIMPSON, F. Cisternas, L. Carvajal, S. Fuentes, and M. Dondero. ESCUELA DE ALIMENTOS, Universidad Catolica De Valparaiso, WADDINGTON 716, VALPARAISO, Chile

JUSTIFICATION. At present, consumers expect higher organoleptic and nutritional quality from seafood products. The rate of quality deterioration of a food product varies with its microenvironment and is strongly dependent on its temperature history. Cultured Salmon farming started 30 years ago and today is a very large and stable industry. The climatic conditions, low costs and increasing demand, have led to an almost exponential growth in this sector and Chile has become the second largest salmon exporter in the world (over 100.000 metric ton/year).

OBJECTIVES. The aim of this research study were to develop a time-temperature integrator (TTI) for smoked salmon and determine if a surface mounted indicator will always predict their shelf-life.

METHODS. Changes in the quality of Smoked Salmon were determined by chemical and microbiological analyses and correlated with results obtained from sensory evaluations. Chemical indicators used to determine quality were: pH, total volatile bases (TVB), Trimethylamine (TMA), Histamine (HIS), Hypoxanthine (Hx) and K value. Microbiological test was total count. To determine the accuracy of a surface mounted indicator a heat transfer study was carried out. Smoked Salmon samples were considered as a parallelepiped and thermophysical properties were obtained in a wide range. The mathematical model was developed in one, two and three dimensions with convective boundary conditions and symmetry with the center point. The partial differential equations were solved using an explicit numerical method.

RESULTS. TVB, TMA, pH, K value and total count had a significant correlation (p < 0.05) with storage time and sensory evaluation. Heat transfer simulation with an activation energy of 18000 cal/mol effectively monitored the shelf life of smoked salmon during transport and refrigerated storage.

SIGNIFICANCE. Experimental results for quality changes complemented with a theoretical research study reveled that a TTI with an activation energy of 18000 cal/mol and surface mounted will accurately predict the shelf life of smoked salmon.