Comparisons of Non-thermal Decontamination Methods to Improve the Safety for Raw Beef Consumption

The object of this study was to examine non-thermal treatments to reduce foodborne pathogens in raw beef. Foodborne-illness pathogens were inoculated in the raw beef. Death rates of foodborne illness pathogens were evaluated by non-thermal decontamination methods(high pressure processing at 500MPa[HPP] for 2min, 5min, and 7min; UV LED radiation at 405nm[UV LED] for 2h, 6h, and 24h; hypochlorous acid water at 100ppm[HAW] for 1min, 3min, and 5min; 2.5% lactic acid[LA] for 1min, 3min, and 5min; modified atmosphere that replaced O2 to CO2 [MAP] for 24h and 48​​h; bio-gel[BG] application for 24h and 48h. Quality characteristics were measured after applying the practical non-thermal decontamination methods. After the treatment of HPP for 7min, inactivity rates were 4.4-6.7Log CFU/g for E. coli, Salmonella, and L. monocytogenes and 1.7Log CFU/g for S. aureus (p <0.05). After the treatment with UV LED for 24h, the reduced cell counts were 0.5, 0.7, and 0.3Log CFU/g for E. coli , Salmonella , and S. aureus, respectively(p <0.05), but no significant reduction for L. monocytogenes. When the beef was treated with HAW was treated for 5min, 0.6Log CFU/g of E. coli, 0.5Log CFU/g of Salmonella, 0.4Log CFU/g of S. aureus , and 0.5Log CFU/g of L. monocytogenes were inactivated. After the beef was treated with LA for 5min, 1.8Log CFU/g of E. coli, 3.0Log CFU/g of Salmonella, 1.3Log CFU/g of S. aureus, and 1.9Log CFU/g of L. monocytogenes were inactivated. MAP for 48h caused the inactivation of 0.3Log CFU/g of E. coli, 0.1Log CFU/g of Salmonella. After treatment of BG for 48h, 0.3Log CFU/g of E. coli and 0.4Log CFU/g of Salmonella were significantly decreased(p <0.05). HPP cooked the beef after 2min of treatment. HAW and BG changed the surface color of the beef, LA reduced the pH of beef (p<0.05). However, UV LED did not cause any changes in the beef quality properties. These results indicates that UV LED can improve the food safety of raw beef.

Prospects for the use of porous composite materials in products for respiratory protection from viral and bacterial infections

The effectiveness of cleaning the air flow from the droplet and dispersed phases of liquids, which are the main medium for transporting most respiratory viruses from the carrier to the infected person, was assessed. Samples of Cribrol, polymer composite with a three-dimensional fractal mesh structure of through and non-through pores from 5 to 150 μm, were examined. The experiments showed high hygroscopic properties of this material, providing moisture absorption of more than 700 % of the dry weight of the test sample. It has been found that Cribrol can undergo thermal decontamination in heating devices and can be used repeatedly. This material has been concluded to be promising for use in PPE, and its structure can easily be adapted to various respiratory personal protective equipment (PPE).

Thermal Decontamination Technologies for Microorganisms and Mycotoxins in Low-Moisture Foods

The contamination risks of microorganisms and mycotoxins in low-moisture foods have heightened public concern. Developing novel decontamination technologies to improve the safety of low-moisture foods is of great interest in both economics and public health. This review summarizes the working principles and applications of novel thermal decontamination technologies such as superheated steam, infrared, microwave, and radio-frequency heating as well as extrusion cooking. These methods of decontamination can effectively reduce the microbial load on products and moderately destruct the mycotoxins. Meanwhile, several integrated technologies have been developed that take advantage of synergistic effects to achieve the maximum destruction of contaminants and minimize the deterioration of products. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 12 is March 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Thermal Decontamination of Spent Activated Carbon Contaminated with Radiocarbon and Tritium

The thermal desorption of tritium (3H, T) and radiocarbon (14C) from spent activated carbon was investigated and three thermal desorption steps were established: the vaporization of homogeneously condensed molecules, the desorption of molecules physically binding with the carbon surface, and the decomposition of chemisorbed molecules. A model-free kinetic analysis was conducted to establish the optimum condition of vacuum thermal desorption. Physisorbed species, including tritiated water (HTO) and 14CO2, were effectively removed by vacuum thermal desorption. However, a fraction of 14C, which may take the form of carbon molecules in pyrocarbon form during the heating process, was not removed, even at a high temperature of 1000 °C under a vacuum of 0.3–0.5 Pa. Oxidative peeling of the pore surfaces by filling the evacuated pores with pure oxygen via vacuum thermal desorption and heating to 700 °C was found to be effective for reducing the level of 14C to a level below the established free-release criterion (1 Bq/g) when treating spent activated carbon with 14C radioactivity levels of 162 and 128 Bq/g. The reactivation of the spent granular activated carbon (GAC) by vacuum thermal desorption followed by surface oxidation was also confirmed by the slightly enhanced pore volumes when compared to those of virgin spent activated carbon.

A Predictive Model of the Temperature-Dependent Inactivation of Coronaviruses

The COVID-19 pandemic has stressed healthcare systems and supply lines, forcing medical doctors to risk infection by decontaminating and reusing single-use medical personal protective equipment. The uncertain future of the pandemic is compounded by limited data on the ability of the responsible virus, SARS-CoV-2, to survive across various climates, preventing epidemiologists from accurately modeling its spread. However, a detailed thermodynamic analysis of experimental data on the inactivation of SARS-CoV-2 and related coronaviruses can enable a fundamental understanding of their thermal degradation that will help model the COVID-19 pandemic and mitigate future outbreaks. This paper introduces a thermodynamic model that synthesizes existing data into an analytical framework built on first principles, including the rate law and the Arrhenius equation, to accurately predict the temperature-dependent inactivation of coronaviruses. The model provides much-needed thermal decontamination guidelines for personal protective equipment, including masks. For example, at 70 °C, a 3-log (99.9%) reduction in virus concentration can be achieved in ≈ 3 minutes and can be performed in most home ovens without reducing the efficacy of typical N95 masks. The model will also allow for epidemiologists to incorporate the lifetime of SARS-CoV-2 as a continuous function of environmental temperature into models forecasting the spread of coronaviruses across different climates and seasons.

A Predictive Model of the Temperature-Dependent Inactivation of Coronaviruses

The COVID-19 pandemic has stressed healthcare systems and supply lines, forcing medical doctors to risk infection by decontaminating and reusing single-use medical personal protective equipment. The uncertain future of the pandemic is compounded by limited data on the ability of the responsible virus, SARS-CoV-2, to survive across various climates, preventing epidemiologists from accurately modeling its spread. However, a detailed thermodynamic analysis of experimental data on the inactivation of SARS-CoV-2 and related coronaviruses can enable a fundamental understanding of their thermal degradation that will help model the COVID-19 pandemic and mitigate future outbreaks. This paper introduces a thermodynamic model that synthesizes existing data into an analytical framework built on first principles, including the rate law and the Arrhenius equation, to accurately predict the temperature-dependent inactivation of coronaviruses. The model provides much-needed thermal decontamination guidelines for personal protective equipment, including masks. For example, at 70 °C, a 3-log (99.9%) reduction in virus concentration can be achieved in ≈ 3 minutes and can be performed in most home ovens without reducing the efficacy of typical N95 masks. The model will also allow for epidemiologists to incorporate the lifetime of SARS-CoV-2 as a continuous function of environmental temperature into models forecasting the spread of coronaviruses across different climates and seasons.