In recent years the consumer’s preference for highly convenient food possessing superior characteristics, high nutritional value with minimum processing, easy to eat, safe, should have a longer shelf life and mouth-watering taste has increased. All these demands of the consumer are impossible to be fulfilled by the existing thermal treatments, which provide food with reduced nutritional and sensory qualities with lesser shelf life. This diverted the attention of food professionals towards non-thermal technologies which are eco-friendly, energy-efficient, and do not process food at a higher temperature for a longer time. As a result, non-thermal technology delivers food with higher nutritional and sensory values and with longer shelf life. Non-thermal treatments are cost-effective technologies that constitute a newer bunch of tools that are developing steadily and are being explored across the globe. This review discusses in brief non-thermal technologies like ultraviolet, pulse electric field, high-pressure processing, ultrasonication, cold plasma, and supercritical carbon dioxide.

Emulsion systems are extensively used in the food processing sector and the use of natural emulsifiers like proteins for stabilizing emulsion has been in demand from consumers due to increased awareness about the consumption of healthy food. Numerous methods are available for the preparation of emulsion, but ultrasound got more attention among common methods owing to its economical and environment-friendly characteristics. The physical effects caused by to bursting of the cavity bubble, result in reduced droplet size, thus forming an emulsion with appreciable stability. Ultrasound ameliorates the emulsifying characteristics of natural emulsifiers like protein and improves the storage stability of the emulsion by positively boosting the rheological, emulsifying characteristics, improving zeta potential, and reducing average droplet size. The stability of protein-based emulsion is affected by environmental stresses hence conjugate of protein with polysaccharide showed good emulsifying characteristics. However, the data on the effect of ultrasound parameters on emulsifier properties is lacking and there is a need to develop a sonication device that can carry out large-scale emulsification operation. The review covers the principles and mechanisms of ultrasound-assisted formation of protein-based and protein-based conjugate emulsions. Further, the effect of ultrasound on various characteristics of protein-based emulsion is also explored. This review will provide concise data to the researchers to extend their experiments in the area of ultrasound emulsification which will help in commercializing the technology at the industrial scale.