Limited proteolysis of myofibrillar proteins by bromelain decreases toughness of coarse dry sausage

Commercial protease bromelain was added to a coarsely chopped dry sausage, ‘chorizo’, at different concentrations ranging from 6 to 600 U per 100 g. Bromelain exerted a clear proteolytic effect on myosin and other myofibrillar proteins, depending on enzyme concentration, as revealed by non-protein nitrogen data and electrophoretic patterns. Proteolysis brought about a significant (P < 0.1) tenderising effect on sausages, according to sensory analysis. Tenderisation was evaluated as being excessive and undesirable at high concentrations, while it showed no significant differences in parameters related to sausage quality when used at low concentrations. The difference with enzyme-free control was statistically significant (P < 0.1), as demonstrated by both triangle and duo-trio discriminative tests. Bromelain exerted its activity mainly within an initial 48 h period at refrigeration temperatures.