Effects of atmospheric pressure plasma jet on the conformation and physicochemical properties of myofibrillar proteins from king prawn (Litopenaeus vannamei)

Cold Plasma-Mediated Treatments for Shelf Life Extension of Fresh Produce: A Review of Recent Research Developments

Fresh produce, like fruits and vegetables, are important sources of nutrients and health-promoting compounds. However, incidences of foodborne outbreaks associated with fresh produce often occur; it is thus important to develop and expand decay-control technologies that can not only maintain the quality but can also control the biological hazards in postharvest, processing, and storage to extend their shelf life. It is under such a situation that plasma-mediated treatments have been developed as a novel nonthermal processing tool, offering many advantages and attracting much interest from researchers and the food industry. This review summarizes recent developments of cold plasma technology and associated activated water for shelf life extension of fresh produce. An overview of plasma generation and its physical-chemical properties as well as methods for improving plasma efficiency are first presented. Details of using the technology as a nonthermal agent in inhibiting spoilage and pathogenic microorganisms, inactivating enzymes, and modifying the barrier properties or imparting specific functionalities of packaging materials to extend shelf life of food produce are then reviewed, and the effects of cold plasma-mediated treatment on microstructure and quality attributes of fresh produce are discussed. Future prospects and research gaps of cold plasma are finally elucidated. The review shows that atmospheric plasma-mediated treatments in various gas mixtures can significantly inhibit microorganisms, inactive enzyme, and modify packaging materials, leading to shelf life extension of fresh produce. The quality attributes of treated produce are not compromised but improved. Therefore, plasma-mediated treatment has great potential and values for its application in the food industry.

Effects of Mild Oxidative and Structural Modifications Induced by Argon Plasma on Physicochemical Properties of Actomyosin from King Prawn ( Litopenaeus vannamei)

In the present work, the structure and physicochemical properties of natural actomyosin (NAM) extracted from king prawn ( Litopenaeus vannamei) and subjected to atmospheric pressure plasma jet (APPJ) generated in argon gas as a function of the treatment time were examined. The results revealed that prawn NAM exhibited a correlating decrease in pH from 7.06 ± 0.03 to 6.92 ± 0.02 and a slight increase ( p > 0.05) in solubility from 91.89 ± 1.57 to 96.86 ± 1.19 within the first few minutes of plasma exposure as a result of the formation of soluble aggregates. A rise in turbidity was also noted, confirming the occurrence of protein aggregation. These changes were also accompanied by a rise in emulsifying activity from 48.96 ± 1.66 to 67.31 ± 1.39 m²/g ( p < 0.05) and a nearly 50% increase in foaming capacity after 5 min of APPJ exposure. The modulation of these properties occurred as a result of conformational changes in NAM evident by various complementary structural analyses conducted. Overall, these findings show that mild oxidation from argon plasma can be used for modification of protein functionality and emphasize the need for optimal selection of plasma processing conditions.