Combination effects of ultrasonic and basic amino acid treatments on physicochemical properties of emulsion sausage

This study was aimed to investigate the effects of ultrasound, basic amino acids (l-lysine and l-arginine), and their combination treatments on the physicochemical properties of emulsion sausages and raw meat batters. A combination of ultrasonic and l-lysine treatment resulted in 69.8% decrease in cooking loss, 70.6% decrease in total expressible fluids, 11.1% decrease in expressible fat in sausages as compared to those with ultrasonic treatment; and 15.7% reduction in cooking loss, 18.8% reduction in total expressible fluids and 6.8% reduction in expressible fat in sausages as compared to those with l-lysine treatments, respectively. Similarly, a combination of ultrasonic and l-arginine treatment led to 91.9% decrease in cooking loss, 89.5% decrease in total expressible fluids, 27.1% decrease in expressible fat in sausages as compared to those with ultrasonic treatment; and 48.3% reduction in cooking loss, 43.9% reduction in total expressible fluids and 14.9% reduction in expressible fat in sausages as compared to those with l-arginine treatment, respectively. Meanwhile, their combination treatments were more effective than their individual treatments in improving textural properties. Confocal laser scanning microscopy revealed that the emulsion sausages treated with a combination of ultrasound and l-lysine/l-arginine exhibited smaller and more uniform fat/oil droplets, compared to the emulsion sausages treated with ultrasound, l-lysine, or l-arginine, respectively. l-Lysine/l-arginine treatments could lead to changes in the rheological pattern of meat batters, while ultrasonic treatment could not. Nevertheless, ultrasonic treatment resulted in increase in the storage modulus and apparent viscosity of meat batter regardless of l-lysine/l-arginine in most cases. Summarily, ultrasound could assist l-lysine/l-arginine to improve the quality characteristics of emulsion sausage.