High hydrostatic pressure and soybean protein addition to beef patties: Effects on the formation of mixed aggregates and technological parameters

The effect of replacing 20% of meat proteins with soy protein isolate (SPI) and high hydrostatic pressure (HHP, 300 MPa-5 min) on technological, color and texture parameters of beef patties was studied. Also, HHP-induced interactions between myofibrillar and soybean proteins were analyzed in mixtures of isolated proteins. HHP decreased expressible moisture and increased cooking loss, hardness and Kramer shear force of patties (p < 0.05), while addition of SPI had the opposite effect on those variables. Although HHP and SPI separately decreased redness (a*) in raw patties, their combination led to a* values similar to those of control ones, which represents an interesting advantage. HHP induced protein-protein interactions at the expense of water-protein ones. Simultaneous denaturation of meat and soybean proteins induced specific aggregation between sarcoplasmic proteins and alpha' and alpha polypeptides (beta-conglycinin), and between myofibrillar proteins and AB (glycinin) and beta polypeptide (beta-conglycinin), which led to a three-dimensional mixed matrix.