Assessment and optimisation of ultrasound as a pretreatment in the production of enzyme-modified cheese

Abstract

Ultrasound (US) technology has the potential to modify protein structures and accelerate enzymatic reactions through the application of low-frequency high energy. This study aimed to produce enzyme-modified cheese (EMC), which has a concentrated cheese flavour, using US pretreatment in a two-stage process involving proteolysis followed by lipolysis. The optimisation of the proteolysis stage was performed by adjusting the US power, US processing time, and proteolysis time. Optimal conditions were determined to be 46.28 W US power, 9.8 min US pretreatment, and 10.49 h proteolysis. These conditions resulted in a 12.5% reduction in the proteolysis time and produced an EMC comparable with one produced without US pretreatment for 12 h proteolysis. The characteristics of the final EMC were evaluated after the lipolysis stage and it was found that the free fatty acid and volatile content were primarily determined by lipolysis, which was not influenced by US pretreatment applied prior to proteolysis.