Cold atmospheric plasma-induced protein modification: Novel nonthermal processing technology to improve protein quality, functionality, and allergenicity reduction

With the constant increase in protein demand globally, it is expedient to develop a strategy to effectively utilize protein, particularly those extracted from plant origin, which has been associated with low digestibility, poor techno-functional properties, and inherent allergenicity. Several thermal modification approaches have been developed to overcome these limitations and showed excellent results. Nevertheless, the excessive unfolding of the protein, aggregation of unfolded proteins, and irregular protein crosslinking have limited its application. Additionally, the increased consumer demand for natural products with no chemical additives has created a bottleneck for chemical-induced protein modification. Therefore, researchers are now directed toward other nonthermal technologies, including high-voltage cold plasma, ultrasound, high-pressure protein, etc., for protein modification. The techno-functional properties, allergenicity, and protein digestibility are greatly influenced by the applied treatment and its process parameters. Nevertheless, the application of these technologies, particularly high-voltage cold plasma, is still in its primary stage. Furthermore, the protein modification mechanism induced by high-voltage cold plasma has not been fully explained. Thus, this review meets the necessity to assemble the recent information on the process parameters and conditions for modifying proteins by high-voltage cold plasma and its impact on protein techno-functional properties, digestibility, and allergenicity.