Solar/ClO2 system inactivates fungal spores in drinking water: Synergy, efficiency and mechanisms.

The risk of fungal pollution in drinking water has been paid attention. Solar/chlorine dioxide (ClO2) combined system is an environment-friendly, economical and efficient disinfection method, especially for countries and regions that are economically backward and still exposed to unsafe drinking water. In this paper, the kinetics, influencing factors, mechanism and regrowth potential of inactivated Aspergillus niger (A. niger) spores by solar/ClO2 were reported for the first time. The inactivation curve can be divided into three stages: instant inactivation within 1-2 min, slow linear inactivation and finally a tail. The synergistic factors produced by solar/ClO2 in terms of log reduction and maximum inactivation rate were 1.194 and 1.112, respectively. The inhibitory effect on the regrowth of A. niger spores inactivated by solar/ClO2 was also stronger than that by ClO2 alone. Strongly oxidizing reactive species produced by solar/ClO2 accelerated the accumulation of endogenic reactive oxygen species (ROS) caused by oxidation stress of A. niger spores, improving the inactivation ability of the system. The inactivation order of A. niger spores was: loss of culturability, accumulation of intracellular ROS, loss of membrane integrity, leakage of intracellular species and change of morphology. The inactivation performance of solar/ClO2 was better than solar/chlor(am)ine according to the comparison of inactivation efficiency and regrowth potential. Results also suggested that solar/ClO2 process was more suitable for the treatment of ground water sources.

Antimicrobial efficiency of chlorine dioxide and its potential use as anti-SARS-CoV-2 agent: mechanisms of action and interactions with gut microbiota.

Chlorine dioxide (ClO2) is a disinfectant gas with strong antifungal, antibacterial, and antiviral activities. Applied on hard, non-porous surfaces as an aqueous solution or gas, the ClO2 exerts antimicrobial activity through its interaction and destabilization of cell membrane proteins, as well as through DNA/RNA oxidation, triggering cell death. As for viruses, the ClO2 promotes protein denaturalization mechanisms, preventing the union between the human cells and the viral envelope. Currently, ClO2 has been pointed out as a potential anti-SARS-CoV-2 clinical treatment for use in humans with the ability to oxidize the cysteine residues in the spike protein of SARS-CoV-2, inhibiting the subsequent binding with the Angiotensin-converting enzyme type 2 receptor, located in the alveolar cells. Orally administered ClO2 reaches the gut tract and exacerbates the symptoms of COVID-19, generating a dysbiosis with gut inflammation and diarrhea as side effects, and once absorbed, produces toxic effects including methemoglobinemia and hemoglobinuria, which can trigger respiratory diseases. These effects are dose-dependent and may not be entirely consistent between individuals since the gut microbiota composition is highly heterogeneous. However, to support the use of ClO2 as an anti-SARS-CoV-2 agent, further studies focused on its effectiveness and safety both in healthy and immunocompromised individuals, are needed.

Assessing the bleaching effect of an experimental stabilized chlorine dioxide agent used for internal bleaching purposes

Aim Assessing the intracoronal bleaching effectiveness of an experimental chlorine dioxide product, based on the walking bleach technique. Methods Extracted bovine incisors were artificially stained with bovine blood and filled with zinc phosphate cement at cementoenamel junction level. Teeth were divided into 3 groups (n=10): (SP) sodium perborate added with distilled water, (CD) chlorine dioxide and (C) control - dry cotton inserted into the pulp chamber. Bleaching agents were used at 0, 7 and 14 days. VITA Easyshadetm (∆Eab) was used to analyze tooth color at the 7th, 14th and 21st days, based on the CIE2000 system. Data were analyzed through ANOVA and Tukey's test. Results There were no statistically significant differences in Δb, ΔE, ΔE00 and ΔWID between CD and the control group. These parameters have shown significant differences between CD and SP, which differed from the control. However, they did not show significant differences either in the control group or in CD at the 7th, 14th and 21st days. Values recorded for SP at the 7th day differed from those recorded at the 14th and 21st days. Δa has shown differences within the same group at the 7th, 14th and 21st days. There was no difference between groups, when they were compared at the same day (7th and 14th). The control group differed from SP at the 21st day. CD did not differ from the other two groups. ΔL did not show differences between groups and times. Conclusion Stabilized chlorine dioxide (0.07%, at pH 3.5) should not be used as intracoronal bleaching agent along with the walking bleach technique.

Ultrasound, Acetic Acid, and Peracetic Acid as Alternatives Sanitizers to Chlorine Compounds for Fresh-Cut Kale Decontamination.

Chlorinated compounds are usually applied in vegetable sanitization, but there are concerns about their application. Thus, this study aimed to evaluate ultrasound (50 kHz), acetic acid (1000; 2000 mg/L), and peracetic acid (20 mg/L) and their combination as alternative treatments to 200 mg/L sodium dichloroisocyanurate. The overall microbial, physicochemical, and nutritional quality of kale stored at 7 °C were assessed. The impact on Salmonella enterica Typhimurium was verified by plate-counting and scanning electron microscopy. Ultrasound combined with peracetic acid exhibited higher reductions in aerobic mesophiles, molds and yeasts, and coliforms at 35 °C (2.6; 2.4; 2.6 log CFU/g, respectively). Microbial counts remained stable during storage. The highest reduction in Salmonella occurred with the combination of ultrasound and acetic acid at 1000 mg/L and acetic acid at 2000 mg/L (2.8; 3.8 log CFU/g, respectively). No synergistic effect was observed with the combination of treatments. The cellular morphology of the pathogen altered after combinations of ultrasound and acetic acid at 2000 mg/L and peracetic acid. No changes in titratable total acidity, mass loss, vitamin C, or total phenolic compounds occurred. Alternative treatments presented equal to or greater efficacies than chlorinated compounds, so they could potentially be used for the decontamination of kale.

Could polyhexanide and chlorine dioxide be used as an alternative to chlorhexidine? A systematic review

ABSTRACT BACKGROUND: Maintenance of oral microbiota balance is the simplest way to prevent infectious oral diseases, through controlling dental biofilm. Combined use of mouthwash and mechanical removal has been shown to be a very effective way for this. OBJECTIVES: To identify clinical studies comparing the antimicrobial effect and possible adverse effects and/or side effects of chlorhexidine-based mouthwashes with those of mouthwashes containing chlorine dioxide and/or polyhexanide, for controlling oral microbiota. DESIGN AND SETTING: Systematic review designed by the stomatology sector of postgraduation in applied dental sciences of Bauru Dentistry School, University of São Paulo, Brazil. METHODS: A systematic review was conducted using online databases (PubMed, Embase, Web of Science and Science Direct) up to April 8, 2020. The search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: The studies included comprised eight articles published between 2001 and 2017. A total of 295 young adults, adults and elderly people were evaluated (males 44.75% and females 55.25%). Three articles compared polyhexanide with chlorhexidine and five articles compared chlorine dioxide with chlorhexidine. No studies comparing all three mouthwashes were found. The concentrations of the study solutions were quite varied, and all rinses had an antimicrobial effect. In four studies, it was stated that no side effects or adverse effects had been found. Three studies did not address these results and only one study addressed side effects and/or adverse effects. CONCLUSION: Mouthwashes containing chlorine dioxide and polyhexanide are viable alternatives to chlorhexidine, since they reduce oral biofilm and have little or no reported side or adverse effects.

Could polyhexanide and chlorine dioxide be used as an alternative to chlorhexidine? A systematic review.

BACKGROUND: Maintenance of oral microbiota balance is the simplest way to prevent infectious oral diseases, through controlling dental biofilm. Combined use of mouthwash and mechanical removal has been shown to be a very effective way for this. OBJECTIVES: To identify clinical studies comparing the antimicrobial effect and possible adverse effects and/or side effects of chlorhexidine-based mouthwashes with those of mouthwashes containing chlorine dioxide and/or polyhexanide, for controlling oral microbiota. DESIGN AND SETTING: Systematic review designed by the stomatology sector of postgraduation in applied dental sciences of Bauru Dentistry School, University of São Paulo, Brazil. METHODS: A systematic review was conducted using online databases (PubMed, Embase, Web of Science and Science Direct) up to April 8, 2020. The search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: The studies included comprised eight articles published between 2001 and 2017. A total of 295 young adults, adults and elderly people were evaluated (males 44.75% and females 55.25%). Three articles compared polyhexanide with chlorhexidine and five articles compared chlorine dioxide with chlorhexidine. No studies comparing all three mouthwashes were found. The concentrations of the study solutions were quite varied, and all rinses had an antimicrobial effect. In four studies, it was stated that no side effects or adverse effects had been found. Three studies did not address these results and only one study addressed side effects and/or adverse effects. CONCLUSION: Mouthwashes containing chlorine dioxide and polyhexanide are viable alternatives to chlorhexidine, since they reduce oral biofilm and have little or no reported side or adverse effects.

Factors associated with the consumption of chlorine dioxide to prevent and treat COVID-19 in the Peruvian population: a cross-sectional study.

BACKGROUND: Chlorine dioxide has been promoted as an alternative for the prevention and treatment of COVID-19, especially in Peru, despite the lack of evidence to support its efficacy. This study aimed to evaluate the factors associated with chlorine dioxide consumption in the Peruvian population. METHODS: Analytical cross-sectional study. An adult Peruvian population was evaluated where chlorine dioxide consumption was divided into two groups according to the purpose of use: as prevention (individuals without COVID-19 history) and as treatment (individuals with COVID-19 history). The associated factors in each group were evaluated using Poisson regressions with the bootstrapping resampling method. RESULTS: Of 3610 participants included, 3213 reported no history of COVID-19, and 397 had been infected. The prevalence of chlorine dioxide consumption to prevent or treat COVID-19 was 8 and 16%, respectively. Factors either positively or negatively associated with chlorine dioxide consumption for prevention were male sex (aPR: 1.36; 95% CI: 1.09-1.71), being an adult or older adult (aPR: 0.54; 95% CI: 0.35-0.82), having a health sciences student within the family unit (aPR: 1.38; 95% CI: 1.02-1.87), using medical information as the main source of information of COVID-19 (aPR: 0.57; 95% CI: 0.40-0.80), having comorbidities for COVID-19 (aPR: 1.36; 95% CI: 1.01-1.82), considering COVID-19 dangerous and deadly (aPR: 0.57; 95% CI: 0.45-0.74), using medications (aPR: 1.59; 95% CI: 1.25-2.06) and plants to prevent COVID-19 (aPR: 1.69; 95% CI: 1.21-2.36), considering chlorine dioxide ineffective (aPR: 0.18; 95% CI: 0.18-0.24), and being uninformed of its efficacy (aPR: 0.21; 95% CI: 0.16-0.28). In addition, factors associated with chlorine dioxide consumption for treatment were considering COVID-19 dangerous and deadly (aPR: 0.56; 95% CI: 0.33-0.96), considering chlorine dioxide ineffective (aPR: 0.22; 95% CI: 0.12-0.42), and being uninformed of its efficacy (aPR: 0.15; 95% CI: 0.07-0.32). CONCLUSIONS: The prevalence of chlorine dioxide consumption to treat COVID-19 was higher than prevent. It is important to apply information strategies, prioritizing population groups with certain characteristics that are associated with a higher consumption pattern.

Acute kidney injury secondary to chlorine dioxide use for COVID-19 prevention.

Chlorine dioxide has been historically used as a disinfecting agent for drinking water supplies and surfaces. Widespread use as an alternative option for prevention and treatment of COVID-19 has emerged due to a lack of specific treatment. We present the case of a 55-year-old male who developed acute kidney injury and disseminated intravascular coagulation after chlorine dioxide prophylactic ingestion, with regression after therapy with hemodialysis.

Chlorine dioxide: an evaluation based on a microbial decay approach during mango packing process.

Mango is highly consumed worldwide; nonetheless, its consumption has been related to foodborne outbreaks. This study was performed to evaluate bacterial transference during mango postharvest management and the feasibility of adopting chlorine dioxide as first choice disinfectant in mango packinghouse. Chlorine dioxide (3 and 5 ppm) and sodium hypochlorite (100 and 200 ppm) were evaluated at different turbidity and times against Salmonella Choleraesuis and Listeria monocytogenes. Bacterial transference was higher from water to fruit than vice-versa (49.17%). Chlorine dioxide (5 ppm) achieved the highest Salmonella reductions at low turbidity reaching 2.13 Log10 at 10 min; meanwhile, Listeria was totally reduced in all conditions. Bacterial decay kinetic showed that chlorine dioxide 5 ppm was 34-fold faster than sodium hypochlorite at 200 ppm in reducing 1 Log10 of Salmonella. Chlorine dioxide reached faster bacterial inactivation decay over sodium hypochlorite; its usage is safe and meets the regulatory standards set for mango processing.

Dióxido de cloro y derivados del cloro para prevenir o tratar la COVID-19: revisión sistemática / Chlorine dioxide and chlorine derivatives for the prevention or treatment of COVID-19: a systematic review

RESUMEN Objetivos: Realizar una revisión sistemática acerca de la efectividad y seguridad del uso de dióxido de cloro y derivados del cloro, en la prevención o el tratamiento de la COVID-19. Materiales y métodos: Se siguieron las pautas internacionales de elaboración de revisiones sistemáticas de PRISMA y el Manual Cochrane para revisiones sistemáticas de intervenciones. La estrategia de búsqueda la desarrolló un bibliotecario y la revisaron dos de los autores. Se complementó la búsqueda electrónica con una búsqueda manual. Se incluyeron ensayos clínicos aleatorizados, estudios cuasiexperimentales, estudios de cohorte, estudios de casos y controles, estudios de corte transversal y reportes de casos; y se excluyeron estudios in vitro o realizados en animales. Dos revisores, de forma independiente, seleccionaron los estudios según los criterios de elegibilidad definidos, usando el aplicativo web Rayyan, en caso de discordancia se hizo partícipe a un tercer revisor. El protocolo de la revisión sistemática se registró en PROSPERO (CRD42020200641). Resultados: No se identificó ningún estudio publicado ni en proceso de publicación que haya evaluado el uso del dióxido de cloro o derivados del cloro, administrado por vía inhalatoria, oral o parenteral en humanos, como agente preventivo o terapéutico de la COVID-19 o en infecciones por otros coronavirus. Solo se identificó el registro de un único estudio catalogado como observacional que hasta ahora no tiene resultados. Conclusiones: A la fecha, no existe evidencia científica que apoye el uso del dióxido de cloro o derivados del cloro para prevenir o tratar la COVID-19.

ABSTRACT Objectives: To systematically review the effectiveness and safety of chlorine dioxide solution and chlorine derivatives used in the prevention or treatment of COVID-19. Methods: This review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) and follows the guidelines provided in the Cochrane Handbook for Systematic Reviews of Interventions. A librarian developed and executed the search strategy; it was further reviewed by two of the authors and complemented by manual search. Randomized clinical trials, quasi-experimental studies, cohort studies, case-control studies, cross-sectional studies, and case reports were included; in vitro or animal studies were excluded. Abstract and full-text screening according to pre-defined eligibility criteria were performed by two reviewers independently using web application Rayyan QCRI. Disagreements on study selection were resolved by a third reviewer. The systematic review protocol was registered in PROSPERO (CRD42020200641). Results: Neither published nor pre-print studies evaluating the use of chlorine dioxide or derivatives on SARS-CoV-2 infection were identified. The only finding was an unpublished observational study registry which has no results released yet. Conclusions: To date, there are no scientific evidence to uphold the use of chlorine dioxide or derivatives as preventive or therapeutic agents against COVID-19.

Modeling the inactivation of Lactobacillus brevis DSM 6235 and retaining the viability of brewing pitching yeast submitted to acid and chlorine washing.

This study aimed to model the inactivation of Lactobacillus brevis DSM 6235 while retaining the viability of yeasts during washing brewer's yeast with phosphoric acid and chlorine dioxide. The independent variables in the acid washing were pH (1-3) and temperature (1-9 °C), whereas in the washing with chlorine dioxide, concentration (10-90 mg/L) and temperature (5-25 °C) were assessed. The predictive models obtained for the four response variables γLA, γCl (decimal reduction of L. brevis DSM 6235), Vf/V0LA, and Vf/V0Cl (brewer's yeast viability ratio) were found to have R2 > 0.80 and values of Fcalc > Freference. Then, the models were considered predictive and statistically significant (p < 0.10). Our results indicated that phosphoric acid and chlorine dioxide washing resulted in up to 7 and 6.4 (log CFU/mL) decimal reductions of L. brevis DSM 6235, respectively. On the other hand, the viability of the brewer's yeast ranged from 22.3 to 99.4%. L. brevis DSM 6235 inactivation was significantly influenced by parameters pH(Q) and T°C(Q) when phosphoric acid was applied, and by parameters mg/L(L), mg/L(Q), T°C(Q), and mg/L × T°C when ClO2 was applied. The validation of the models resulted in bias (γLA, 0.93/Vf/V0LA, 0.99 - γCl, 1.0/Vf/V0Cl, 0.99) and accuracy values (γLA, 1.12/Vf/V0LA, 1.01 - γCl, 1.08/Vf/V0Cl, 1.03). The results of this study indicate that it might be possible to decontaminate brewer's yeast through acid and chlorine dioxide washing while keeping its viability. This procedure will result in the reduction of costs and the lower generation of brewer's waste.

Chlorine dioxide and chlorine derivatives for the prevention or treatment of COVID-19: a systematic review. / Dióxido de cloro y derivados del cloro para prevenir o tratar la COVID-19: revisión sistemática.

OBJECTIVES: To systematically review the effectiveness and safety of chlorine dioxide solution and chlorine derivatives used in the prevention or treatment of COVID-19. METHODS: This review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) and follows the guidelines provided in the Cochrane Handbook for Systematic Reviews of Interventions. A librarian developed and executed the search strategy; it was further reviewed by two of the authors and complemented by manual search. Randomized clinical trials, quasi-experimental studies, cohort studies, case-control studies, cross-sectional studies, and case reports were included; in vitro or animal studies were excluded. Abstract and full-text screening according to pre-defined eligibility criteria were performed by two reviewers independently using web application Rayyan QCRI. Disagreements on study selection were resolved by a third reviewer. The systematic review protocol was registered in PROSPERO (CRD42020200641). RESULTS: Neither published nor pre-print studies evaluating the use of chlorine dioxide or derivatives on SARS-CoV-2 infection were identified. The only finding was an unpublished observational study registry which has no results released yet. CONCLUSIONS: To date, there are no scientific evidence to uphold the use of chlorine dioxide or derivatives as preventive or therapeutic agents against COVID-19.

OBJETIVOS: Realizar una revisión sistemática acerca de la efectividad y seguridad del uso de dióxido de cloro y derivados del cloro, en la prevención o el tratamiento de la COVID-19. MATERIALES Y MÉTODOS: Se siguieron las pautas internacionales de elaboración de revisiones sistemáticas de PRISMA y el Manual Cochrane para revisiones sistemáticas de intervenciones. La estrategia de búsqueda la desarrolló un bibliotecario y la revisaron dos de los autores. Se complementó la búsqueda electrónica con una búsqueda manual. Se incluyeron ensayos clínicos aleatorizados, estudios cuasiexperimentales, estudios de cohorte, estudios de casos y controles, estudios de corte transversal y reportes de casos; y se excluyeron estudios in vitro o realizados en animales. Dos revisores, de forma independiente, seleccionaron los estudios según los criterios de elegibilidad definidos, usando el aplicativo web Rayyan, en caso de discordancia se hizo partícipe a un tercer revisor. El protocolo de la revisión sistemática se registró en PROSPERO (CRD42020200641). RESULTADOS: No se identificó ningún estudio publicado ni en proceso de publicación que haya evaluado el uso del dióxido de cloro o derivados del cloro, administrado por vía inhalatoria, oral o parenteral en humanos, como agente preventivo o terapéutico de la COVID-19 o en infecciones por otros coronavirus. Solo se identificó el registro de un único estudio catalogado como observacional que hasta ahora no tiene resultados. CONCLUSIONES: A la fecha, no existe evidencia científica que apoye el uso del dióxido de cloro o derivados del cloro para prevenir o tratar la COVID-19.

Photodynamic therapy for cutaneous hemangiosarcoma in dogs.

Cutaneous hemangiosarcoma is a malignant neoplasia that frequently occurs in dogs. The most effective treatment requires wide surgical excision of the tumor. To avoid mutilating surgeries, photodynamic therapy (PDT) could serve as an alternative treatment. This study aimed to treat cutaneous hemangiosarcomas in dogs using PDT with aluminium-chloride-phthalocyanine nanoemulsion (AlClPc-nano) as photosensitizer. Eight dogs with histopathological diagnosis of naturally occurring cutaneous hemangiosarcoma were treated. Animals were given intra and peritumoral injections of AlClPc-nano (13.3 µM). After 15 min, the masses were LED irradiated at a wavelength of 658-662 nm (80 mW potency) for 25 min (120 J/cm2 fluency). The number of sessions was based on lesion observations, with PDT sessions repeated every 7 days until the mass was no longer macroscopically visible. On that occasion, an excisional biopsy of the area was taken for histopathology analysis. Blood was collected from each animal before each PDT session and excisional biopsy for hematological analysis (blood counts; liver and kidney function). The number of PDT sessions varied from 2 to 4, depending on the size of the initial mass. Seven of the eight cases demonstrated complete remission of neoplasia. Microscopic analysis of the excisional biopsies showed necrosis and hemorrhage only, with no cancer cells, except in one case. During the treatment, inflammation and necrosis were macroscopically observed in the treated areas. The dogs did not show any alteration in blood parameters that could be related to the PDT. In conclusion, PDT with AlClPc-nano is a safe and effective treatment for cutaneous hemangiosarcoma in dogs.

Evaluation of intervention measures at different stages of the production chain in Argentinian exporting abattoirs.

Antimicrobial treatments could help to decrease the transmission of microorganisms to beef carcasses and abattoir environments. The aim of this study was to evaluate the effectiveness of interventions in reducing Shiga toxin genes (stx1 and stx2) presence in a commercial abattoir. Intervention measures included the application of electrolytically generated hypochlorous acid to steer pens (experiment 1), chlorinated water, electrolytically generated hypochlorous acid, and isoclor to steer pens (experiment 2), electrolytically generated hypochlorous acid to knocking pens (experiment 3), and aqueous ozone and electrolytically generated hypochlorous acid onto beef carcasses (experiment 4). Detection of stx in samples was performed with BAX® System Real-Time PCR Assay. Our results showed that treatment with pressurized electrolytically generated hypochlorous acid and isoclor were effective to reduce stx presence from hides on steer pens. Although there is no single strategy to ensure the reduction of stx presence in a commercial abattoir, the combined application of several antimicrobial interventions would be ideal.

Evaluation of Hot Water, Gaseous Chlorine Dioxide, and Chlorine Treatments in Combination with an Edible Coating for Enhancing Safety, Quality, and Shelf Life of Fresh-Cut Cantaloupes.

Fresh-cut cantaloupes have been implicated in numerous foodborne outbreaks of salmonellosis. Commercial aqueous wash treatments are limited in their ability to inactivate Salmonella enterica. Our objective was to evaluate the efficacy of hot water, gaseous chlorine dioxide, and chlorine on enhancing microbial safety and sensory qualities of fresh-cut cantaloupes. Cantaloupes were inoculated with an S. enterica cocktail (serovars Michigan, Mbandaka, and Poona) and treated with chlorine (200 ppm of free chlorine) for 40 min, 5 mg/L gaseous chlorine dioxide for 4.5 h, and hot water (76.1°C) for 3 min. Fresh-cut cantaloupes were prepared from treated whole cantaloupes and divided into two sets; one set of samples was treated with NatureSeal to evaluate its effect on shelf life and sensory quality and the second set (control) was packed without further treatment. Fresh-cut samples were stored at 4°C for up to 21 days. For the sensory quality parameters analyzed (color, water loss, and texture), the samples treated with NatureSeal had significantly better quality ( P < 0.05) than did the control samples. All treatments significantly reduced ( P < 0.05) the pathogen populations on the rind of the whole melons and on the fresh-cut samples prepared from the treated melons. All fresh-cut samples prepared from melons treated with hot water were negative for Salmonella throughout the storage period except for the samples treated with hot water and NatureSeal and evaluated on day 7. The fresh-cut samples prepared from melons treated with chlorine dioxide and chlorine were negative for Salmonella after 21 days of storage. These results provide a framework to producers of fresh-cut cantaloupes for the potential use of hot water as an intervention treatment in combination with NatureSeal for enhancing the microbiological safety and quality of this commodity.

Ultrasound improves chemical reduction of natural contaminant microbiota and Salmonella enterica subsp. enterica on strawberries.

New sanitization methods have been evaluated to improve food safety and food quality and to replace chlorine compounds. However, these new methods can lead to physicochemical and sensory changes in fruits and vegetables. The present study evaluated the effects of acetic acid, peracetic acid, and sodium dodecylbenzenesulfonate isolated or combined with 5min of ultrasound treatment (40kHz, 500W) on strawberry quality over 9days of storage at 8°C. The strawberry natural contaminant microbiota (molds and yeasts, mesophilic aerobic and lactic acid bacteria), physicochemical quality (pH, total titratable acidity, total soluble solids, vitamin C, and color), sensory quality (triangle test) and inactivation of Salmonella enterica subsp. enterica intentionally inoculated onto strawberries were analyzed. Ultrasound increased the effect of all chemical compounds in the reduction of aerobic mesophilic, molds and yeasts. The best treatment for those groups of microorganisms was ultrasound combined with peracetic acid (US+PA) that reduced 1.8 and 2.0logcfu/g during 9days of storage. Bactericidal effect of peracetic acid was also improved by ultrasound inactivation of S. enterica, reaching a decimal reduction of 2.1logcfu/g. Moreover, synergistic effects were observed in contaminant natural microbiota inactivation for all tested compounds during storage, without any major physicochemical or sensory alteration to the strawberries. Therefore, ultrasound treatment can improve the effect of sanitizers that are substitutes of chlorine compounds without altering the quality of strawberries during storage. Acetic acid (PubChem CID: 176); Peracetic acid (PubChem CID: 6585); Sodium dodecylbenzenesulfonate (PubChem CID: 18372154).

A comparison of the bleaching effectiveness of chlorine dioxide and hydrogen peroxide on dental composite.

This study was carried out to verify if composites could be bleached using chlorine dioxide as compared with hydrogen peroxide. 3M ESPE Filtek Z350 Universal Restorative discs were prepared (n=40), with dimensions 5 mm diameter x 2 mm thickness. The discs were divided into 4 groups of 10 discs each. Color assessment was performed by CIEDE2000. The discs were stained with coffee, tea, wine and distilled water (control) solutions for 14 days, 5 hours daily. Color assessment was repeated on stained discs and followed by bleaching of 5 discs from each group using chlorine dioxide and hydrogen peroxide in-office systems. Finally, a last color assessment was performed and compared statistically. DE2000 after bleaching was very close to baseline for both the bleaching agents, although chlorine dioxide showed better results than hydrogen peroxide. After staining, there was a clinically significant discoloration (∆E2000≥3.43) for the tea, coffee and wine groups, and discoloration (∆E2000) was seen more in the wine group as compared to tea and coffee. Overall, the control group (distilled water) had the least color change in the three intervals. After bleaching, the color in all specimens returned close to the baseline. The color differences between bleaching and baseline were less than 3.43 for all groups. The obtained results show that chlorine dioxide is slightly superior to hydrogen peroxide in the bleaching of composites, while maintaining the shade of the composite close to the baseline.