Effect of high pressure processing on myofibrillar proteins and textural properties of beef patties

SZERMAN NATALIA; SPERONI FRANCISCO; VAUDAGNA SERGIO R.

Buenos Aires

Jornada; VI Jornadas Internacionales de Proteinas y Coloides Alimentarios (JIPCA VI); 2011

FCEyN-UBA y CIDCA FCE-UNLP, CONICET

High pressure processing (HPP) has been proposed as a possible mean for improving functional properties of proteins, since it induces protein denaturation, aggregation or gelation. The aim of this study was to evaluate the effects of HPP on myofibrillar beef proteins and their potential influence on textural properties of beef patties.  Patties were elaborated with 80% beef meat, 10% water and 10% beef fat (A: no additives; B: 2% NaCl and 0.5% sodium tripolyphosphate). After freezing, A and B patties were submitted to 300MPa-5min (A300-5, B300-5). Then, patties treated by HPP and those non-pressurized (A0 and B0) were kept frozen. Electrophoretic profiles of meat proteins extracted by 0.1M NaCl; 0.6M NaCl; 0.6M NaCl + 0.8% SDS or 0.6M NaCl + 0.8% SDS + 5% b-mercaptoethanol (100°C) were monitored by SDS-PAGE. Thermal behavior of meat proteins was studied by DSC. Texture profile analysis of grilled patties was also performed. Extracted proteins with 0.6M NaCl + 0.8% SDS + 5% b-mercaptoethanol from all treatments presented similar electrophoretic profiles. This result suggested that proteins, which could not be extracted by 0.6M NaCl or 0.6M NaCl + 0.8% SDS, were involved in the formation of high pressure-induced aggregates stabilized by disulfide bonds. According to DSC, HPP caused total denaturation of actin and a decrease in temperature denaturation of myosin, probably due to a structure modification. Addition of salts (B0) diminished denaturation temperature and enthalpy of myosin and actin, being this effect enhanced by HPP (B300-5). HPP increased hardness, springiness and chewiness for patties with (B300-5) or without additives (A300-5) in relation to their respective controls (B0 and A0). This HP-induced increase in texture parameters was greater in patties without salts than in those formulated with salts. Cohesiveness did not present differences in B patties. Our results suggest that HPP promoted the aggregation of myofibrillar proteins, and these aggregates would improve the binding between meat particles. This phenomenon would be reflected by the increase in texture parameters of grilled patties. Since these effects were also observed in patties that were formulated without salts, we concluded that HPP may be a way to reduce the content of additives.