CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
High pressure processing of beef patties: effects of pressure level and salts concentration on thermal behaviour and aggregation of myofibrillar proteins
Autor/es:
SPERONI, FRANCISCO; SZERMAN, NATALIA; VAUDAGNA, SERGIO
Lugar:
Santa Catarina
Reunión:
Workshop; International Nonthermal Food Processing Workshop; 2013
Resumen:
Functional properties of proteins can be improved by high pressure processing (HPP) since it induces protein denaturation, aggregation or gelation. The effects of HPP on myofibrillar beef proteins was studied on patties manufactured with 80% beef meat, 10% water, 10% fat and salts (NaCl: 0, 1, 2%; sodium trypoliphosphate, STPP, 0, 0.25, 0.5%). Patties were submitted to different HPP treatments: 0.1-200-300MPa (5min, 5°C). Thermal behaviour was studied by DSC. Molecular characterization of meat proteins extracted by buffers containing 0.1M NaCl; 0.6M NaCl; 0.6M NaCl+1%SDS were carried out by SDS-PAGE. The application of 200MPa to patties formulated without salts produced a 50% denaturation of myosin head. 1%NaCl favored HPP-induced myosin and actin denaturation (69% and 74%, respectively). However, 0.25%STPP partially protected myosin head (22% denaturation degree) and did not modify actin compared to non HPP-treated patties. Also, the addition of 1%NaCl+0.25%STPP diminished the denaturation degree of myosin head (25%) and actin (27%), suggesting that these proteins are partially protected by STPP against HP-induced denaturation. The protective effect of STPP on myosin head was not detected when salts concentrations where higher (2%NaCl+0.5%STPP). Most of the myofibrillar and sarcoplasmic proteins were denatured when patties were HPP-treated at 300MPa, without salts or with 1%NaCl, 0.25%STPP, 1%NaCl+0.25%STPP. Moreover, in those samples, a structure at 50.9±1.2ºC (probably stabilized by hydrogen bonds) appeared after 300MPa treatment. From SDS-PAGE analysis, it can be observed for patties without salts, that the aggregation of sarcoplasmic and myofibrillar proteins was more significant after the application of 300MPa than after 200 MPa. The presence of salts only affected the sensitivity of actin and myosin head at 200MPa. HPP treatments and salts concentrations affected myofibrillar proteins, increasing their denaturation and inducing the formation of aggregates, mainly at 300MPa. These modifications would induce changes in water holding capacity and texture of beef patties