Changes of Mechanical and Thermal Properties of Cranberries Subjected to Ultrasound Treatment

Abstract

Abstract The aim of the study was to investigate the effect of ultrasound treatment in osmotic solution, carried out at different time and solutions, on mechanical and thermal properties of cranberries. Ultrasound treatment was applied for 30 and 60 min in liquid mediums such as 61.5 % sucrose solution and 30 % sucrose solution with 0.1 % steviol glycosides addition. Before the ultrasound treatment samples were subjected to traditional operations (cutting, blanching). The traditional operations and ultrasonic treatment of whole fruits did not influence or slightly influenced dry matter content and mechanical properties. The cutting had impact on thermal properties to the highest extent due to the exposition of fruits’ flesh. The combination of cutting and sonication decreased thermal conductivity which suggests that mass transfer was more pronounced. The sonication had greater influence when compared to only ultrasonic treatment. Combined both cutting and blanching with ultrasonic treatment led to greater changes in cranberries properties.