Protozoan parasites can survive under ambient and refrigerated storage conditions when associated with a range of substrates. Consequently, various treatments have been used to inactivate protozoan parasites (Giardia, Cryptosporidium, and Cyclospora) in food, water, and environmental systems. Physical treatments that affect survival or removal of protozoan parasites include freezing, heating, filtration, sedimentation, UV light, irradiation, high pressure, and ultrasound. Ozone is a more effective chemical disinfectant than chlorine or chlorine dioxide for inactivation of protozoan parasites in water systems. However, sequential inactivation treatments can optimize existing treatments through synergistic effects. Careful selection of methods to evaluate inactivation treatments is needed because many studies that have employed vital dye stains and in vitro excystation have produced underestimations of the effectiveness of these treatments.

Electrolyzed oxidizing water (EOW) can be considered in the agrofood industry as a new antimicrobial agent with disinfectant, detoxifying, and shelf-life improvement properties. EOW is produced by electrolysis of water, with no added chemicals, except for sodium chloride. The antifungal and detoxifying mechanisms of EOW depend mainly on: pH, oxidation-reduction potential (ORP), and available chlorine concentration (ACC). EOW offers many advantages over other conventional chemical methods, including less adverse chemical residues, safe-handling, secure, energy-saving, cost-effective, and environmentally-friendly. As a result, EOW could be used for the development of safer and more socially acceptable methods for fungi decontamination and mycotoxin detoxification. This review contains an overview of EOW effectiveness to decontaminate non-toxigenic and mycotoxigenic fungi, its safety and efficacy for mycotoxin detoxification, the proposed mechanism of action of EOW on fungal cells, and the chemical mechanism of action of EOW on mycotoxins. Finally, conclusions and future research necessities are also outlined.

Chlorine is a widely used disinfectant and oxidant used for an array of municipal and industrial applications, including potable water, swimming pools, and cleaning of membranes. The most popular method to verify the concentration of free chlorine is the colorimetric method based on DPD (N, N-diethyl-p-phenylenediamine), which is fast and reasonably cheap, but DPD and its product are potentially toxic. Therefore, a novel, environmentally friendly colorimetric method for the quantification of residual chlorine based on the food additive pyridoxamine (4-(aminomethyl)-5-(hydroxymethyl)-2-methylpyridin-3-ol) was investigated. Pyridoxamine is a B6 vitamin with an absorption maximum at 324 nm and fluorescence emission at 396 nm. Pyridoxamine reacts rapidly and selectively with free chlorine, resulting in a linear decrease both in absorbance and in emission, giving therefore calibration curves with a negative slope. The pyridoxamine method was successfully applied for the quantification of free chlorine from 0.2 to 250 mg/L. Using 1 cm cuvettes, the limit of quantification was 0.12 mg Cl₂/L. The pyridoxamine and the DPD methods were applied to actual environmental samples, and the deviation between results was between 4% and 9%. While pyridoxamine does not react with chloramine, quantification of monochloramine was possible when iodide was added, but the reaction is unfavourably slow.

This study was conducted to seek optimum concentration and treatment time of fermented rice water (Rizen) to disinfect food-borne bacteria in kitchen towel. 2.65 log∧10 cfu/g of E. coli was reduced when double or triple diluted fermented rice water was treated during 2 hours. In case of concentrated fermented rice water, crude and double diluted solutions showed complete sterilization after 2 and 5 hours, respectively. On the other hand, triple, quadruple, quintuple diluted solutions needed 24 hours for complete sterilization.

Salmonella can survive for extended periods of time in low-moisture environments posing a challenge for modern food production. This dangerous pathogen must be controlled throughout the production chain with a minimal risk of dissemination. Limited information is currently available describing the behavior and characteristics of this important zoonotic foodborne bacterium in low-moisture food production environments and in food. In our study, the phenotypes related to low-moisture survival of 46 Salmonella isolates were examined. Most of the isolates in the collection could form biofilms under defined laboratory conditions, with 57% being positive for curli fimbriae production and 75% of the collection positive for cellulose production, which are both linked with stronger biofilm formation. Biocides in the factory environment to manage hygiene were found to be most effective against planktonic cells but less so when the same bacteria were surface dried or present as a biofilm. Cellulose-producing isolates were better survivors when exposed to a biocide compared with cellulose-negative isolates. Examination of Salmonella growth of these 18 serotypes in NaCl, KCl, and glycerol found that glycerol was the least inhibitory of these three humectants. We identified a significant correlation between the ability to survive in glycerol and the ability to survive in KCl and biofilm formation, which may be important for food safety and the protection of public health.

To determine the efficacy of electrolysed oxidizing (EO) water in inactivating Vibrio parahaemolyticus on kitchen cutting boards and food contact surfaces. Cutting boards (bamboo, wood and plastic) and food contact surfaces (stainless steel and glazed ceramic tile) were inoculated with V. parahaemolyticus. Viable cells of V. parahaemolyticus were detected on all cutting boards and food contact surfaces after 10 and 30 min, respectively, at room temperatures. Soaking inoculated food contact surfaces and cutting boards in distilled water for 1 and 3 min, respectively, resulted in various reductions of V. parahaemolyticus, but failed to remove the organism completely from surfaces. However, the treatment of EO water [pH 2·7, chlorine 40 ppm, oxidation-reduction potential 1151 mV] for 30, 45, and 60 s, completely inactivated V. parahaemolyticus on stainless steel, ceramic tile, and plastic cutting boards, respectively. EO water could be used as a disinfecting agent for inactivating V. parahaemolyticus on plastic and wood cutting boards and food contact surfaces. Rinsing the food contact surfaces with EO water or soaking cutting boards in EO water for up to 5 min could be a simple strategy to reduce cross-contamination of V. parahaemolyticus during food preparation.

Alkaline electrolyzed water (REW) is known for its cleaning action. The aim of this work was to assess REW effectiveness in reducing microbial load on surfaces intended for contact with food. Stainlesssteel surfaces were experimentally contaminated, bacterial inactivation was tested before and after treatment with REW. Treatment with REW was operated spraying it on the contaminated plates until drying. Tests were conducted for Salmonella spp., Listeria spp., Staphylococcus aureus and Escherichia coli. The treatment revealed different degrees of sanitizing activity of REW on different bacterial species, with higher efficacy on E. coli and Salmonella spp. than S. aureus, Listeria spp.. Statistical analysis revealed a significant microbial load reduction (p<0.01) after treatment with REW, suggesting that it has a good disinfectant activity which, along with its easy and safe use, makes it a good alternative to many other more widely used disinfectants.

Recently, reports have been published on the occurrence of chlorate mainly in fruits and vegetables. Chlorate is a by-product of chlorinating agents used to disinfect water, and can be expected to be found in varying concentrations in drinking water. Data on potable water taken at 39 sampling points across Europe showed chlorate to range from < 0.003 to 0.803 mg l –¹ with a mean of 0.145 mg l –¹. Chlorate, however, can also be used as a pesticide, but authorisation was withdrawn in the European Union (EU), resulting in a default maximum residue limit (MRL) for foods of 0.01 mg kg –¹. This default MRL has now led to significant problems in the EU, where routinely disinfected water, used in the preparation of food products such as vegetables or fruits, leaves chlorate residues in excess of the default MRL, and in strict legal terms renders the food unmarketable. Due to the paucity of data on the chlorate content of prepared foods in general, we collated chlorate data on more than 3400 samples of mainly prepared foods, including dairy products, meats, fruits, vegetables and different food ingredients/additives. In total, 50.5% of the food samples contained chlorate above 0.01 mg kg –¹, albeit not due to the use of chlorate as a pesticide but mainly due to the occurrence of chlorate as an unavoidable disinfectant by-product. A further entry point of chlorate into foods may be via additives/ingredients that may contain chlorate as a by-product of the manufacturing process (e.g. electrolysis). Of the positive samples in this study, 22.4% revealed chlorate above 0.1 mg kg –¹. In the absence of EU levels for chlorate in water, any future EU regulations must consider the already available WHO guideline value of 0.7 mg l –¹ in potable water, and the continued importance of the usage of oxyhalides for disinfection purposes.

Cet article est la synthese thematique d'une enquete menee en 1996 aupres de professionnels (industriels, fabricants et chercheurs) du nettoyage et de la desinfection dans les industries alimentaires sur le theme de la reduction de la consommation d'eau et de la production d'effluents polluonts, liee a ces operations. Dans cette optique, les produits chimiques recommandes sont les produits combines (detergent + desinfectant) encore trop peu utilises. L'utilisation de produits sous forme mousse ou gel permet aussi de reduire les quantites d'eau necessaires. Il semble interessant de generaliser les nettoyages prealables a sec (raclage, brossage avec aspiration, pousse a l'air comprime, etc...) permettant d'economiser de l'eau et des produits detergents, voire de recuperer de la matiere premiere. A l'inverse, les jets haute pression, tres repandus, sont a proscrire. Des efforts restent a faire (du point vue technique comme du point de vue de la mesure de leur efficacite) pour mettre au point et valider des methodes de desinfection plus "seches" (chimiques sans rincage, physiques a l'aide d'ultraviolets, d'ultra-sons ou de laser impulsionnel,...). Il apparait clairement que le nettoyage et la desinfection de surfaces non en contact avec les aliments demandent aussi une meilleure gestion de l'eau, et des etudes sur la necessite de certains rincages et desinfections sont fortement souhaitables. Enfin, des outils technologiques tels des capteurs pour le tri des flux ou des techniques separatives permettront de rationnaliser les consommations, de recycler l'eau et les produits (en particulier dans les systemes de nettoyage en place) et de reduire les rejets provoques par les operations de nettoyage et de desinfection