Inactivation of two SARS-CoV-2 virus surrogates by electron beam irradiation on large yellow croaker slices and their packaging surfaces

Inactivation mechanism of cold plasma combined with 222 nm ultraviolet for spike protein and its application in disinfecting of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible virus that has precipitated a worldwide pandemic of coronavirus disease since 2019. Developing an effective disinfection strategy is crucial to prevent the risk of surface cross-contamination by SARS-CoV-2. This study employed pseudovirus and the receptor-binding domain (RBD) protein of SARS-CoV-2 as models to investigate the spike protein inactivation process and its underlying mechanisms using a novel nonthermal technology. Cold plasma combined with 222 nm ultraviolet (CP+UV) treatment was applied to accelerate the generation of reactive species and enhance sterilization efficiency. The results indicated that the binding activity of RBD protein was completely inhibited at specific concentrations (0.01-0.05 mg/cm2) with corresponding treatment times of 15-30 s. The mechanism potentially involves the reactive species generated by CP+UV, which react with the spike protein RBD of SARS-CoV-2, leading to the loss of SARS-CoV-2 infectivity by causing damage to the β-sheet structure and chemical bonds in the RBD protein. Validated by a biosafety level 3 (BSL3) laboratory, the CP+UV treatment for 30 s could completely inactivate SARS-CoV-2 with a concentration of 19054 ± 1112 TCID50/cm2. Therefore, this study potentially provides a novel disinfection strategy for the inactivation of SARS-CoV-2 on surface cross-contamination.

SARS-CoV-2 transmission via maritime cold chains: A statistical analysis of nucleic acid detection results of cold chain food imported from Fuzhou ports

Numerous epidemic outbreaks related to cold chains have occurred since the coronavirus disease 2019 (COVID-19) outbreak, suggesting the potential danger of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through cold chain foods (CCFs). By analyzing SARS-CoV-2 RNA contamination of CCFs imported from Fuzhou ports, this study evaluated the contamination and transmission of SARS-CoV-2 RNA via maritime cold chains, with the aim of provide suggestions for CCFs supervision and public health management. The statistical analysis included 131,385 samples. The majority of the CCFs imported into Fuzhou ports was aquatic raw food that originated in Southeast Asia (57.08 %), South America (19.87 %), and South Asia (11.22 %). South Asia had the highest positivity rate of 0.37 %, followed by Southeast Asia (0.21 %) and South America (0.08 %). The positivity rate showed that the outer packaging of CCFs was the most easily contaminated, accounting for 81.33 % of all positive samples. This suggested that CCFs storage and loading processes were the weak links vulnerable to SARS-CoV-2 contamination. The positivity rates in outer packaging, inner packaging, and content of raw food were 0.48 %, 0.08 %, and 0.05 %, respectively, which were obviously higher than those of processed and refined food. This indicated that increasing the mechanization of factories and implementing sensible worker management practices may decrease viral contamination. The monthly positivity rates varied widely from 0 % (March 2021) to 0.40 % (January 2021), with an average of 0.19 %. The positivity rates in outer packaging, inner packaging and content of crustaceans from Southeast Asia were 2.47 %, 0.41 %, and 0.69 %, which were approximately 5-14 times higher than those of fish and cephalopods. Meanwhile, the monthly detection number show that SARS-CoV-2 epidemic prevention strategies affected the trade of imported CCFs.

Lesson learned from COVID-19 pandemic for the future of food industry

With WHO announcing COVID-19 no longer as a public health emergency of international concern (PHEIC) on May 5, 2023, coupled with the fact that the majority of the countries of the world have dropped strict city lockdown or border closure, this perhaps signals the end of the COVID-19 crisis caused by the SARS-CoV-2 virus. However, the COVID-19 pandemic has resulted in far-reaching effects affecting nearly every aspect of our lives and society. Notably, the food industry including agriculture, food manufacturers, food logistics, distributors and retailers have all felt the profound impact and had experienced significant stress during the pandemic. Therefore, it is essential to retrospect the lessons that can be learned from this pandemic for the food industry. This short review aims to address the food safety issues related to the COVID-19 pandemic by focusing on its foodborne transmission potential, innovations of virus detection strategies suitable for food industry; development of phathogenicaidal methods and devices to inactivate SARS-CoV-2 virus (particularly in industrial scale); and the set-up of related food regulations and guidelines as preventive and control measures for preventing the spread of SARS-CoV-2 virus through the food supply chain during the pandemic. This article may provide useful references for the food industry to minimize the food safety impact of COVID-19 (as well as other respiratory virus) and allows them to better prepare for similar future challenges.

Integrated proteomics and metabolomics analysis revealed the mechanisms underlying the effect of irradiation on the fat quality of Chinese bacon

Irradiation increases the security and storage period of preserved Chinese bacon; nevertheless, the biological mechanisms underlying the changes in fat quality caused by irradiation are unknown. We investigated the influence of irradiation on Chinese bacon by proteomic and metabolomic. We identified 24 proteins that participated in metabolism and 40 common differential metabolites enriched in 16 signalling pathways. Correlation analysis revealed that irradiation altered 11 pathways shared between the proteome and metabolome, including two lipid metabolism pathways. Acetyl-CoA carboxylase, ACSL, octanoic acid, decanoic acid, palmitic acid, and oleic acid participated in fatty acid biosynthesis. Acyl-CoA thioesterase 1/2/4, enoyl-CoA reductase, acetyl-CoA acyltransferase 1, enoyl-CoA hydratase 2, palmitic acid, and oleic acid participated in unsaturated fatty acid biosynthesis. These findings lay the groundwork for multi-omics research on the effects of irradiation on Chinese bacon quality, assisting in assessing irradiated Chinese bacon quality, and developing effective strategies to standardise quality parameters.