CALIDAD TECNOLÓGICA Y FRESCURA DEL ATÚN ALETA AMARILLA (Thunnus albacares) EMPLEADO COMO MATERIA PRIMA EN LA INDUSTRIA PROCESADORA DE MAZATLÁN, SINALOA TECHNOLOGICAL QUALITY AND FRESHNESS OF YELLOWFIN TUNA (Thunnus albacares) USED AS RAW MATERIAL IN THE PROCESSING INDUSTRY OF MAZATLÁN, SINALOA

The deterioration that yellowfin tuna Thunnus albacares presents from catch and during shipping, is reflected in a decrease in its technological quality as raw material. Technological quality and freshness of yellowfin (YF) tuna catch and stored frozen at -18°C (CF), at the moment of unloading (UL) and prior to the industry processing (PP) were evaluated. For freshness the K index was determined and for technological quality protein solubility, PS, water holding capacity, WHC and gel forming ability, GFA were evaluated. K index was 8.1±1.5%, 17.6±7.0% and 21.9±4.5% for tuna CF, UL and PP respectively. Muscle proteins had low solubility values (CF, 74±7.5%; UL, 50±13.0% and PP, 42±2.9%) and WHC (CF, 2.9±0.5; UL, 3.7±0.9 and PP, 2.6±0.4 g water retained /g protein). Gels prepared with YF tuna muscle showed variable quality (from C to AA). Low and variable technological quality coincided with the high alkali-soluble proteins (CF, 18.1±10.9%; UL, 30.1±10.0% and PP, 58.0±12.3%) proportion. Post-mortem biochemical changes decreased the technological quality of YF tuna, so greater control of board handling and the temperature of post-catch storage is required.