Laser induced shockwave technology: A critical review on mechanism, equipment configuration and application for sustainable food processing

Laser induced shockwave technology is gaining attention worldwide as an emerging, non- destructive and promising non-thermal processing method. Shockwaves with wavelengths of 532 nm and 1064 nm, having pulse durations of 7 ns and 12 ns respectively, are frequently used for laser-induced breakdown in air or water media, resulting from processes of gasification and ionization. It is effective against food-borne pathogens and deteriorating microorganisms thereby extending the shelf life and safety of the food products by maintaining its nutritional quality. Shockwaves can also improve meat tenderness and enhance the extraction of oils, juices, bioactive compounds, and pigments from plant tissues by softening. The existing underwater shockwave technology in the food industry has been limited due to the possibility of water contamination, lack of suitable packaging materials resistant to the disruptive effects of shockwaves, high capital investment and the lack of standard regulations. To overcome these limitations, laser induced shockwaves in air medium can be used as an alternative processing technique. This review deals with the history and concept of shockwaves, its generation mechanism, equipment design, configuration, and its mode of operation. Furthermore, the potential applications of shockwaves in food processing sector are also discussed.