This SpringerBrief provides an overview of ultrasonic emulsification and an update on recent advances in developing stable emulsions for the creation of novel drugs and functional foods, with a focus on bioactive delivery in these products.

Emulsification is the process of combining two or more immiscible liquids to form a semi-stable mixture. These two liquids generally consist of an organic (oil) phase and an aqueous (water) phase that is stabilized by the addition of an emulsifier. Most common emulsions are of the oil-in-water (O/W) type, but can also be of water-in-oil (W/O) or even multiple emulsion types (i.e. double emulsions) in the form of water-in-oil-in-water (W/O/W) or oil-in-water-in-oil (O/W/O) phases. The formation of an emulsion requires input of energy to distribute the disperse phase in the continuous phase in small-sized droplets that are able to resist instability. There is great interest in the use of ultrasound to produce emulsions, as it is able to do so relatively efficiently and effectively compared to existing techniques such as rotor stator, high-pressure homogenization and microfluidization. The interaction of ultrasound with the hydrocolloids and biopolymers that are often used to stabilize emulsions can offer advantages such as improved stability or greater control of formed droplet size distributions.

Autorentext

Dr Thomas Leong is an early career research fellow in the ARC Dairy Innovation Hub based at the University of Melbourne, Australia. He has expertise in the application of ultrasound for the formation of nanoemulsions and double emulsions. Dr Leong's primary research interests are in the area of ultrasound processing, dairy technology and food engineering, and he has published 23 peer-reviewed journal articles, 4 book chapters and 1 patent on topics in these fields.

Professor Sivakumar Manickam (Siva) is a Chemical Engineer specializing Process Engineering of Nanomaterials especially Nanopharmaceuticals at the University of Nottingham, Malaysia campus. His research group focusses on the process development of cavitation based reactors towards technologically important nanomaterials. The group also looks into the development of pharmaceutical nanoemulsions as well as utilizing novel carbon nanomaterials to design biosensors for the early detection of cancer and diabetes. He is also the Associate Dean of Research and Knowledge Exchange, Faculty of Engineering and is the Director of the Centre for Nanotechnology and Advanced Materials. He was the recipient of JSPS fellowship, Japan. He has published ~200 peer reviewed journal and conference papers. He is a Fellow of Royal Society of Chemistry (RSC), Fellow of Higher Education Academy (UK) and member of the Institute of Nanotechnology (IoN).

Wu Li is a Ph.D. candidate from the Sonochemistry Research Team located in the School of Chemistry at the University of Melbourne, Australia. During his MSc, he developed an understanding of sonochemistry from his work on the ultrasound-assisted deposition of metals. He recently started his Ph.D. on the topic of ultrasonic emulsification and its application in dairy systems as part of the ARC Dairy Innovation Hub, with a focus on understanding the fundamental aspects of ultrasonic emulsification.

Dr Gregory J. O. Martin is a Senior Lecturer in bioprocess engineering at The University of Melbourne's Department of Chemical Engineering. His research in the field of bioprocess engineering aims to develop a fundamental understanding for application in large-scale biotechnological processes. This has included research into the use of ultrasound for the production of double emulsions, application of bacteriophages to wastewater treatment, and investigations into the physicochemistry underlying various dairy processes.

Dr Martin has been a Chief Investigator on a number of Australian Research Council Grants including a Discovery Project, two Linkage Projects and the Industry Transformation Research Hub in Dairy Innovation. Dr Martin is an Associate Editor for the Journal of the American Oil Chemists' Society and the head of the Algal Processing Group at The University of Melbourne. He has over 40 publications in leading international journals.

Professor Muthupandian Ashokkumar (Ashok) is a physical chemist specializing in sonochemistry. He teaches undergraduate and postgraduate chemistry and is a senior academic staff member at the School of Chemistry, University of Melbourne. He is also one of the associate deans (International) in the Faculty of Science. Ashok is a respected sonochemist who has developed a number of novel techniques to characterize acoustic cavitation bubbles and has made major contributions to the field of applied sonochemistry in the Materials, Food and Dairy industry. His research team has developed a novel ultrasonic processing technology for improving the functional properties of dairy ingredients. His recent research involves the ultrasonic synthesis of functional nano and biomaterials that can be used in energy production, environmental remediation and diagnostic and therapeutic medicine. He is the deputy director of an Australian Research Council Funded Industry Transformation Research Hub (ITRH; Industry Partner: Mondelez International) and leading the encapsulation project. He has received $ 15 million research grants to support his research work, which includes several industry projects. He is the editor-in-chief of Ultrasonics Sonochemistry, an international journal devoted to sonochemistry research with a Journal Impact Factor of 4.8). He has edited/co-edited several books and special issues for journals; published more than 340 refereed papers in high impact international journals and books; and delivered over 150 invited/keynote/plenary lectures at international conferences and academic institutions. Ashok has successfully organized 10 national/international scientific conferences/workshops and managed a number of national and international competitive research grants. He has served on various University of Melbourne management committees and scientific advisory boards of...

Inhalt
Introduction.- Selection of Operating Parameters.- Applications of Ultrasonic Emulsification.- Mechanisms of Ultrasonic Emulsification.- Influence of Gas Content.- Ultrasonic Frequency.- Delivery of Anti-Cancer Drugs.- Future Trends and Outlook.- References.