Structural and instrumental textural properties of meat patties containing soy protein

The effect of two different types of soy protein namely soy protein flour (SPF) and texturized soy protein (TSP); soy protein extender concentration; cooking times; and cooking temperatures on structural and textural properties of pan-fried patties were studied. Beef patties were formulated using extra lean (10 kg fat/100 kg) ground beef samples, with different concentrations of soy protein (0, 2, 3.5, and 5% kg/kg total mass). They were formed into patties, and cooked on a griddle at different temperatures (177 and 187degreesC) and cooking times (10, 15, and 20 min). Water holding capacity (WHC) and total cooking loss (TCL) were determined. Instrumental textural profiles of the cooked samples were obtained using a Universal Testing Machine Instron. Porosity and pore size distributions were determined by a mercury intrusion porosimeter. The results indicated that increasing soy protein concentration increased WHC and reduced TCL. Beef patties extended with TSP were harder and more cohesive than those extended with SPF. Total mean porosities at the 5% soy protein extender concentration were 0.42 and 0.40 for the SPF and TSP extended samples, respectively. Samples extended with SPF had up to 84% capillary pores.