Sono-physical and sono-chemical effects of ultrasound: Primary applications in extraction and freezing operations and influence on food components

Ultrasound is an advanced non-thermal food-processing technology that has received increasing amounts ofinterest as an alternative to, or an adjuvant method for, conventional processing techniques. This review ex-plores the sono-physical and sono-chemical effects of ultrasound on food processing as it reviews two typicalfood-processingapplicationsthatarepredominantlydrivenbysono-physicaleffects,namelyultrasound-assistedextraction (UAE) and ultrasound-assisted freezing (UAF), and the components modifications to food matricesthatcanbetriggeredbysono-chemicaleffects.Efficiencyenhancementsandqualityimprovementsinproducts(and extracts) using ultrasound are discussed in terms of mechanism and principles for a range of food-matrixcategories,whileeffortstoimproveexistingultrasound-assistpatternswasalsoseen.Furthermore,theprogressof experimental ultrasonic equipments for UAE and UAF as food-processing technologies, the core of the de-velopment in food-processing techniques is considered. Moreover, sono-chemical reactions that are usuallyoverlooked, such as degradation, oxidation and other particular chemical modifications that occur in commonfood components under specific conditions, and the influence on bioactivity, which was also affected by foodprocessing to varying degrees, are also summarised. Further trends as well as some challenges for, and limita-tionsof,ultrasoundtechnologyforfoodprocessing,withUAEandUAFusedasexamplesherein,arealsotakeninto consideration and possible future recommendations were made