Perpustakaan Digital ITB

Sterilization is one of the key technologies to tackle challenges in food spoilages. The common sterilization technique involving thermal treatment still has a lot of drawbacks to food quality. These include the deterioration of nutritional value and organoleptic properties. Thus, ultrasonication is proposed as the alternative since it has minimal alteration on the food quality. Ultrasonication utilizes cavitation bubble collapse to damage bacteria cells. This research is conducted to study the mechanism of bacterial inactivation due to bubble collapse produced by ultrasonication. It is addressed by finite element simulations based on Abaqus/Explicit Dynamic analysis. In this case, Escherichia coli is chosen as the model bacteria with the respective mechanical properties found from literatures. Because of various factors, only the pressure wave is investigated as the inactivation mechanism in this research. The simulation shows that there are two failure modes: bursting and perforating modes. By completing 46 sets of simulations with variations in pressure magnitude and distribution, the author constructed a parametric study based on the damaged cell envelope percentage (DCEP). From the parametric study, presented in the contour plot, the severity of the treatment on different pressure configurations can be determined. It is expected that this parametric study could be used to assist the product development of the ultrasonicator.