Effect of ultrasound on goat cream hydrolysis by lipase: Evaluation on enzyme, substrate and assisted reaction

Abstract

The effect of ultrasound on lipase performance was studied in goat cream hydrolysis. Ultrasound (25 kHz, 22 W/L) was carried out on lipase and/or goat cream under different conditions (pH 6.0; temperature of 25, 40 and 55 °C; up to 5 h). As a pre-treatment, ultrasound did not induce goat cream hydrolysis, but slightly increased lipase activity (up to 12%), depending on the temperature and processing time (activation conditions at 25 °C/45 min and 40 °C/60 min). The fat hydrolysis assisted by ultrasound had higher hydrolysis rate when compared to conventional processing with an increase of 12% at 55 °C, 23% at 40 °C and 28% at 25 °C. The reaction temperature was an important parameter and lower temperatures improved the ultrasound effects. Possibly, these results are associated with the acceleration of mass transfer during ultrasound reaction, as well as the modifications promoted by ultrasound on the enzyme. Therefore, ultrasound was demonstrated as an interesting alternative to improve the goat cream hydrolysis by lipase.