Use of nature‐derived antimicrobial substances as safe disinfectants and preservatives in food processing industries: A review

A Review of CAC-717, a Disinfectant Containing Calcium Hydrogen Carbonate Mesoscopic Crystals

Recent studies on utilizing biological functions of natural substances that mimic the mesoscopic structures (nanoparticles of about 50 to 500 nm) found in plant growth points and coral skeletons have been reported. After the calcium hydrogen carbonate contained in materials derived from plants and coral are separated, the crystals of the mesoscopic structure can be reformed by applying a high voltage under a specific set of conditions. A suspension of these mesoscopic crystals in water (CAC-717) can be used as an effective disinfectant. CAC-717 exhibits universal virucidal activity against both enveloped and non-enveloped viruses as well as bactericidal and anti-prion activity. Moreover, in comparison to sodium hypochlorite, the potency of CAC-717 as a disinfectant is less susceptible to organic substances such as albumin. The disinfection activity of CAC-717 is maintained for at least 6 years and 4 months after storage at room temperature. CAC-717 is non-irritating and harmless to humans and animals, making it a promising biosafe disinfectant. This review explores the disinfection activity of CAC-717 as well as the potential and future uses of this material.

Understanding the Influence of Rheology on Biofilm Adhesion and Implication for Food Safety

Understanding biofilm rheology is crucial for industrial and domestic food safety practices. This comprehensive review addresses the knowledge gap on the rheology of biofilm. Specifically, the review explores the influence of fluid flow, shear stress, and substrate properties on the initiation, structure, and functionality of biofilms, as essential implications for food safety. The viscosity and shear-thinning characteristics of non-Newtonian fluids may impact the attachment and detachment dynamics of biofilms, influencing their stability and resilience under different flow conditions. The discussion spans multiple facets, including the role of extracellular polymeric substances (EPSs) in biofilm formation, the impact of rheological attributes of biofilm on their adhesion to surfaces, and the influence of shear forces between biofilms and substrate's surface characteristics on biofilm stability. Analytical techniques, encompassing rheometry, microscopy, and molecular biology approaches, are scrutinized for their contributions to understanding these interactions. The paper delves into the implications for the food industry, highlighting potential risks associated with biofilm formation and proposing strategies for effective control and prevention. Future research directions and the integration of rheological considerations into food safety regulations are underscored as pivotal steps in mitigating biofilm-related risks. The synthesis of microbiology, materials science, and engineering perspectives offers a multidimensional exploration of rheology-biofilm interactions, laying the groundwork for informed interventions in diverse industrial settings.

Experimental Investigation of Bacterial Inactivation of Beef Using Indirect Cold Plasma in Cold Chain and at Room Temperature

Pathogen contamination is a severe problem in maintaining food safety in the cold chain. Cold plasma (CP) is a novel non-thermal disinfection method that can be applied for the bacterial inactivation of food in appropriate contexts. Currently, research on CP used on food at cold chain temperatures is rare. This work investigated the bacterial inactivation effect of CP on beef at typical cold storage temperatures of 4 and -18 °C and room temperature (25 °C). The reactive species in CP were indirectly tested by evaluating O3, NO3- and NO2- in cold plasma-activated water (PAW), which indicated the highest concentrations of reactive species in CP at 25 °C and the lowest at -18 °C. The bactericidal efficacy of CP treatment against beef inoculated with Escherichia coli at -18 °C, 4 °C, and 25 °C was 30.5%, 60.1%, and 59.5%, respectively. The 4 °C environment was the most appropriate treatment for CP against beef, with the highest bactericidal efficacy and a minor influence on beef quality. The indirect CP treatment had no significant effect on the texture, color, pH, or cooking loss of beef at -18 °C. CP shows significant potential for the efficient decontamination of food at cold chain temperatures.

An Abies Extract Containing Nonvolatile Polyphenols Shows Virucidal Activity against SARS-CoV-2 That Is Enhanced in Increased pH Conditions

Researching the beneficial health properties of wood byproducts can prevent wastage by turning them into valuable resources. In this study, the virucidal activity of two extracts from Abies sachalinensis byproducts, ASE1, and ASE2, against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was investigated. ASE1 is rich in monoterpenoid volatile compounds, whereas ASE2 contains nonvolatile polyphenols. SARS-CoV-2 solutions were mixed with ASE1 or ASE2, and viral titer reduction was evaluated. At their original acidic pH, ASE2 showed stronger virucidal activity than ASE1. The virucidal activity of ASE2 was also significantly enhanced when pH was increased to neutral or basic, which was not the case for ASE1. At a neutral pH, ASE2 induced statistically significant viral titer reduction in 1 min. HCl and NaOH solutions, which had a pH close to that of acidic and basic ASE2 test mixtures, respectively, exhibited no virucidal activity against SARS-CoV-2. Among the SARS-CoV-2 variants, Omicron showed the highest vulnerability to ASE2. Western blotting, RT-PCR, and electron microscopic analysis revealed that neutral ASE2 interacts with SARS-CoV-2 spike proteins and moderately disrupts the SARS-CoV-2 genome and viral envelope. These findings reveal the virucidal potential of ASE2.

The mixed biofilm formed by Listeria monocytogenes and other bacteria: Formation, interaction and control strategies

Listeria monocytogenes is an important foodborne pathogen. It can adhere to food or food contact surface for a long time and form biofilm, which will lead to equipment damage, food deterioration, and even human diseases. As the main form of bacteria to survive, the mixed biofilms often exhibit higher resistance to disinfectants and antibiotics, including the mixed biofilms formed by L. monocytogenes and other bacteria. However, the structure and interspecific interaction of the mixed biofilms are very complex. It remains to be explored what role the mixed biofilm could play in the food industry. In this review, we summarized the formation and influence factors of the mixed biofilm developed by L. monocytogenes and other bacteria, as well as the interspecific interactions and the novel control measures in recent years. Moreover, the future control strategies are prospected, in order to provide theoretical basis and reference for the research of the mixed biofilms and the targeted control measures.

Extraction, Chemical Compositions and Biological Activities of Essential Oils of Cinnamomum verum Cultivated in Vietnam

Cinnamomum verum (Cinnamomum genus) essential oil is commonly used in food preparation and traditional medicines, with a broad spectrum of biological activities. However, research on the extraction of essential oils (EOs) from C. verum cultivated locally in Vietnam is currently limited. Therefore, in this study, the chemical compositions and bioactivities of EOs from the bark and leaves of C. verum collected from the Thai Nguyen and Yen Bai provinces of Vietnam were investigated. The EOs samples were extracted by using water distillation, organic solvent (n-hexane) and ultrasound-assisted (in n-hexane solvent) extraction methods. The chemical composition of the obtained EOs were analyzed by GC-FID and GC/MS analyses. Results showed that the major chemical compositions of C. verum EOs were: (E)-cinnamaldehyde, trans-cinnamic acid, cinnamyl acetate, and benzaldehyde. Furthermore, C. verum EOs exhibited inhibitory activities against two tested cancer cell lines and four bacterial strains. These findings provide essential knowledge about the potential application of C. verum EOs cultivated in Vietnam for the pharmaceutical industry.