Microbial decontamination of particulate food using a pilot-scale atmospheric plasma jet treatment system

Insights into Cold Plasma Treatment on the Cereal and Legume Proteins Modification: Principle, Mechanism, and Application

Cereal and legume proteins, pivotal for human health, significantly influence the quality and stability of processed foods. Despite their importance, the inherent limited functional properties of these natural proteins constrain their utility across various sectors, including the food, packaging, and pharmaceutical industries. Enhancing functional attributes of cereal and legume proteins through scientific and technological interventions is essential to broadening their application. Cold plasma (CP) technology, characterized by its non-toxic, non-thermal nature, presents numerous benefits such as low operational temperatures, lack of external chemical reagents, and cost-effectiveness. It holds the promise of improving proteins' functionality while maximally retaining their nutritional content. This review delves into the pros and cons of different cold plasma generation techniques, elucidates the underlying mechanisms of protein modification via CP, and thoroughly examines research on the application of cold plasma in augmenting the functional properties of proteins. The aim is to furnish theoretical foundations for leveraging CP technology in the modification of cereal and legume proteins, thereby enhancing their practical applicability in diverse industries.

Degradation of Pesticide Residues in Water, Soil, and Food Products via Cold Plasma Technology

Water, soil, and food products contain pesticide residues. These residues result from excessive pesticides use, motivated by the fact that agricultural productivity can be increased by the use of these pesticides. The accumulation of these residues in the body can cause health problems, leading to food safety concerns. Cold plasma technology has been successfully employed in various applications, such as seed germination, bacterial inactivation, wound disinfection, surface sterilization, and pesticide degradation. In recent years, researchers have increasingly explored the effectiveness of cold plasma technology in the degradation of pesticide residues. Most studies have shown promising outcomes, encouraging further research and scaling-up for commercialization. This review summarizes the use of cold plasma as an emerging technology for pesticide degradation in terms of the plasma system and configuration. It also outlines the key findings in this area. The most frequently adopted plasma systems for each application are identified, and the mechanisms underlying pesticide degradation using cold plasma technology are discussed. The possible factors influencing pesticide degradation efficiency, challenges in research, and future trends are also discussed. This review demonstrates that despite the nascent nature of the technology, the use of cold plasma shows considerable potential in regards to pesticide residue degradation, particularly in food applications.

Bactericidal efficacy difference between air and nitrogen cold atmospheric plasma on Bacillus cereus: Inactivation mechanism of Gram-positive bacteria at the cellular and molecular level

As an emerging food processing technology, cold atmospheric plasma (CAP) has attracted great attention in the field of microbial inactivation. Although CAP has been proven to effectively inactivate a variety of foodborne pathogens, there is less research on the inactivation of Bacillus cereus, and the exact inactivation mechanism is still unclear. Elucidating the inactivation mechanism will help to develop and optimize this sterilization method, with the prospective application in industrialized food production. This study aims to explore the bactericidal efficacy difference between air and nitrogen CAP on B. cereus, a typical Gram-positive bacterium, and reveals the inactivation mechanism of CAP at the cellular and molecular level, by observing the change of the cell membrane, cell morphological damage, intracellular antioxidant enzyme activity and cellular biomacromolecules changes. The results showed that both air CAP and nitrogen CAP could effectively inactivate B. cereus, which was due to the reactive oxygen and nitrogen species (RONS) generated by the plasma causing bacterial death. The damage pathways of CAP on Gram-positive bacteria could be explained by disrupting the bacterial cell membrane and cell morphology, disturbing the intracellular redox homeostasis, and destroying biomacromolecules in the cells. The differences in active species generated by the plasma were the main reason for the different bactericidal efficiencies of air CAP and nitrogen CAP, where air CAP producing RONS with stronger oxidative capacity in a shorter time. This study indicates that air CAP is an effective, inexpensive and green technology for B. cereus inactivation, providing a basis for industrial application in food processing.

Inactivation mechanisms of atmospheric pressure plasma jet on Bacillus cereus spores and its application on low-water activity foods

Bacillus cereus spore is one of the most easily contaminated bacterial spores in low-water activity foods such as black pepper. Atmospheric-pressure plasma jet (APPJ) has emerged as an emerging and promising method for microbial inactivation in food processing. This study aimed to investigate the efficacy of APPJ in inactivating spores under various treatment parameters and to examine the resulting alterations in spore structures and internal membrane properties. Meanwhile, the practical application of APPJ for spore inactivation in black pepper was also evaluated. The results indicated that air-APPJ had superior spore inactivation capability compared to N₂ and O₂-APPJ. After 20 min of APPJ treatment (50 L/min, 800 W, and 10 cm), the reduction in spore count (>2 log CFU/g) was significantly greater than that achieved by heat treatment (80℃). The damage of inner membranes was considered as the major reason of the dried spore inactivation by APPJ treatment. Moreover, it achieved a reduction in spore count of > 1 log CFU/g on inoculated black pepper without significantly affecting its color and flavor. Although the antioxidant activity of black pepper was slightly reduced, the overall quality of the product was not considerably affected by plasma treatment. This study concluded that APPJ is an effective technique for spore inactivation, offering promising potential for application in the decontamination of low-water activity foods.