Applications and opportunities for ultrasound assisted extraction in the food industry — A review

Ultrasound assisted extraction (UAE) process enhancement for food and allied industries are reported in this review. This includes herbal, oil, protein and bioactives from plant and animal materials (e.g. polyphenolics, anthocyanins, aromatic compounds, polysaccharides and functional compounds) with increased yield of extracted components, increased rate of extraction, achieving reduction in extraction time and higher processing throughput. Ultrasound can enhance existing extraction processes and enable new commercial extraction opportunities and processes. New UAE processing approaches have been proposed, including, (a) the potential for modification of plant cell material to provide improved bioavailability of micro-nutrients while retaining the natural-like quality, (b) simultaneous extraction and encapsulation, (c) quenching of the radical sonochemistry especially in aqueous systems to avoid degradation of bioactives and (d) potential use of the radical sonochemistry to achieve targeted hydroxylation of polyphenolics and carotenoids to increase bioactivity. The application of ultrasonic assisted extraction (UAE) in food processing technology is of interest for enhancing extraction of components from plant and animal materials. This review shows that UAE technology can potentially enhance extraction of components such as polyphenolics, anthocyanins, aromatic compounds, polysaccharides, oils and functional compounds when used as a pre-treatment step in a unit process. The higher yield obtained in these UAE processes are of major interest from an industrial point of view, since the technology is an “add on” step to the existing process with minimum alteration, application in aqueous extraction where organic solvents can be replaced with generally recognised as safe (GRAS) solvents, reduction in solvent usage, and shortening the extraction time. The use of ultrasonic for extraction purposes in high-cost raw materials is an economical alternative to traditional extraction processes, which is an industry demand for a sustainable development.