Risks for public health related to the presence of chlorate in food

Antimicrobial Effectiveness of Clove Oil in Decontamination of Ready-to-Eat Spinach (Spinacia oleracea L.)

Due to an increased demand for natural food additives, clove oil was assessed as a natural alternative to chemical disinfectants in produce washing. This study assessed the antimicrobial activity of 5 and 10% (v/v) clove oil-amended wash liquid (CO) using a zone of inhibition (ZIB) test and determined the time required to completely inactivate pathogenic bacteria using bacterial death curve analysis. A washing experiment was used to evaluate CO's ability to inhibit bacterial growth on inoculated RTE spinach and in the wash water. The findings showed that Shigella flexneri, Salmonella Typhimurium, and Salmonella enterica recovery were completely inhibited within 5 min. Escherichia coli and Staphylococcus aureus recovery were completely inhibited at 10 and 30 min, respectively. The ZIB test showed that 5% CO had the highest inhibitory effect on both Salmonella strains and E. coli with approximately 10 mm ZIB diameter. Additionally, 5% CO completely inactivated all bacterial strains on spinach samples and in the wash water except for S. aureus. A total of 80 mg/L peracetic acid (PAA) resulted in >2log CFU/mL recovery on experimental washed samples. These findings suggest that 5% CO was highly effective in inhibiting microbial growth on RTE spinach, potentially contributing to sustainable food safety and shelf-life extension strategies.

Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVH). Part 5 (Frozen FVH process water management plan)

Water used in post-harvest handling and processing operations is an important risk factor for microbiological cross-contamination of fruits, vegetables and herbs (FVH). Industrial data indicated that the frozen FVH sector is characterised by operational cycles between 8 and 120 h, variable product volumes and no control of the temperature of process water. Intervention strategies were limited to the use of water disinfection treatments such as peroxyacetic acid and hydrogen peroxide. Chlorine-based disinfectants were not used, and water replenishment was not observed within studied industries. The industrial data, which included 13 scenarios, were used to develop a guidance for a water management plan (WMP) for the frozen FVH sector. A WMP aims to maintain the fit-for-purpose microbiological quality of the process water and consists of: (a) identification of microbial hazards and hazardous events linked to process water; (b) establishment of the relationship between microbiological and physico-chemical parameters; (c) description of preventive measures; (d) description of intervention measures, including their validation, operational monitoring and verification; and (e) record keeping and trend analysis. A predictive model was used to simulate water management outcomes, highlighting the need for water disinfection treatments to maintain the microbiological quality of the process water and the added value of water replenishment. Relying solely on water replenishment (at realistic feasible rates) does not avoid microbial accumulation in the water. Operational monitoring of the physico-chemical parameters ensures that the disinfection systems are operating effectively. Verification includes microbiological analysis of the process water linked to the operational monitoring outcomes of physico-chemical parameters. Food business operators should set up and validate a tailored WMP to identify physico-chemical parameters, as well as microbial indicators and their threshold levels as performance standards for maintaining the fit-for-purpose microbiological quality of the process water during post-harvest handling and processing operations.

Anise essential oil immobilized in chitosan microparticles: a novel bactericidal material for food protection

Foodborne infections in humans are one of the major concerns of the food industries, especially for minimally processed foods (MPF). Thereby, the packaging industry applies free chlorine in the sanitization process, ensuring the elimination of any fecal coliforms or pathogenic microorganisms. However, free chlorine's propensity to react with organic matter, forming toxic compounds such as trihalomethanes and haloacetic acid. Therefore, the present work aimed to synthesize a novel organic biomaterial as an alternative to free chlorine. Chitosan microparticles were produced, with Pimpinella anisum (anise) essential oil immobilized in the biopolymer matrix (MPsQTO). The characterization of this biomaterial was done through GC-MS/MS, FT-IR, and SEM. Antimicrobial assays proved that the MPsQTO presented antibacterial activity for Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, and Bacillus subtilis at 300 µL mL-1 of concentration. The fluorescence microscope also showed the MPsQTO targets the cytoplasmatic membrane, which is responsible for cell death in the first minutes of contact. Studies with the mutant B. subtilis (amy::pspac-ftsZ-gfpmut1) and the Saccharomyces cerevisiae D7 also proved that the biomaterial did not affect the genetic material and did not have any mutagenic/carcinogenic effect on the cells. The sanitization assays with pumpkin MPF proved that the MPsQTO is more effective than free chlorine, increasing the shelf-life of the MPF. Consequently, the novel biomaterial proposed in this work is a promising alternative to traditional chemical sanitizers.

Sanitization of hydroponic farming facilities in Singapore: what, why, and how

This study performed microbial analysis of nutrient film technique (NFT) hydroponic systems on three indoor farms in Singapore (the "what"). To justify the necessity of sanitizing hydroponic systems, strong biofilm-forming bacteria were isolated from the facility and investigated for their influence on Salmonella colonization on polyvinyl chloride (PVC) coupons in hydroponic nutrient solutions (the "why"). Finally, sanitization solutions were evaluated with both laboratory-scale and field-scale tests (the "how"). As a result, the microbiome composition in NFT systems was found to be highly farm specific. The strong biofilm formers Corynebacterium tuberculostearicum C2 and Pseudoxanthomonas mexicana C3 were found to facilitate the attachment and colonization of Salmonella on PVC coupons. When forming dual-species biofilms, the presence of C2 and C3 also significantly promoted the growth of Salmonella (P < 0.05). Compared with hydrogen peroxide (H2O2) and sodium percarbonate (SPC), sodium hypochlorite (NaOCl) exhibited superior efficacy in biofilm removal. At 50 ppm, NaOCl reduced the Salmonella Typhimurium, C2, and C3 counts to <1 log CFU/cm2 within 12 h, whereas neither 3% H2O2 nor 1% SPC achieved this effect. In operational hydroponic systems, the concentration of NaOCl needed to achieve biofilm elimination increased to 500 ppm, likely due to the presence of organic matter accumulated during crop cultivation and the greater persistence of naturally formed multispecies biofilms. Sanitization using 500 ppm NaOCl for 12 h did not impede subsequent plant growth, but chlorination byproduct chlorate was detected at high levels in the hydroponic solution and in plants in the sanitized systems without rinsing.

IMPORTANCE

This study's significance lies first in its elucidation of the necessity of sanitizing hydroponic farming systems. The microbiome in hydroponic systems, although mostly nonpathogenic, might serve as a hotbed for pathogen colonization and thus pose a risk for food safety. We thus explored sanitization solutions with both laboratory-scale and field-scale tests. Of the three tested sanitizers, NaOCl was the most effective and economical option, whereas one must note the vital importance of rinsing the hydroponic systems after sanitization with NaOCl.

[Depressive symptoms in a sample of women with subclinical hypothyroidism and their relationship to chlorates in tap water]

INTRODUCTION

depressive symptoms may develop in subclinical hypothyroidism and their presence usually facilitates recognition and the establishment of replacement treatment; however, recent studies have found no association between the two. Be-sides, thyroid function can be affected by endocrine disruptors and some of them, such as chlorates, can be found in the water we drink.

OBJECTIVES

to know if the type of water consumed may influence the development of depressive symptoms in patients with subclinical hypothyroidism.

METHODS

96 women with subclinical hypothyroidism, without thyroid treatment, par-ticipated from a health area in Spain. We studied, among other variables, the presence of depressive symptoms, type of water consumption (tap, bottled or spring) and the level of chlorates in the tap water.

RESULTS

41.7 % (40) of women presented depressive symptoms and these were related to the consumption of tap water (p = 0.001), resulting in a reliable predictor (OR, 27.79; p = 0.007). Chlorate level in the tap water was 250 µg/L, a value within the maximum limit allowed by law.

CONCLUSIONS

chronic exposure to chlorates in water, in women with subclinical hypo-thyroidism, at levels authorized by law, could favor the inhibition of iodine transport and the appearance of depressive symptoms. It would be interesting to test this hy-pothesis as well as its possible effect on other population profiles.

Dietary exposure assessment of perchlorate and chlorate in infant formulas marketed in Shanghai, China

Perchlorate and chlorate are ubiquitous pollutants that can adversely affect the thyroid function in humans. This study assessed the potential health risks associated with the dietary exposure of infants and young children to perchlorate and chlorate present in infant formulas available in Shanghai. The assessment was based on risk monitoring data from 150 samples of infant formulas in Shanghai between 2020 and 2022, along with the dietary consumption data of infants and young children. The detection rates of perchlorate and chlorate in infant formulas were 46.0% and 98.7%, with mean contents of 9.98 μg/kg and 112.01 μg/kg, and the maximum values of 151.00 μg/kg and 1475.00 μg/kg, respectively. The mean and 95th percentile (P 95) values of daily perchlorate exposure of 0-36-month-old infant and young children via infant formulas were 0.07 and 0.17 μg/kg body weight (bw) per day, respectively, which were lower than the tolerable daily intake (TDI) of perchlorate (0.3 μg/kg bw per day). The mean and P 95 values of chlorate exposure via infant formulas in 0-36-month-old infants and young children were 0.83 and 1.89 μg/kg bw per day, which were lower than the TDI of chlorate (3 μg/kg bw per day). The P 95 exposure of different age groups (0-6 months, 7-12 months and 13-36 months) of infants and young children to perchlorate and chlorate in infant formulas was below the TDI. Therefore, the risk associated with the exposure of 0-36-month-old infants and young children to perchlorate and chlorate from infant formulas in Shanghai is considered acceptable. Prioritizing environmental pollution control efforts to reduce the levels of perchlorate and chlorate in food products is important to safeguard the health of the infants and children under the One Health concept.

Quantification of Chlorate and Perchlorate in a Broad Range of Food Commodities, Including Baby Food, Nutritional Formulas, and Ingredients by LC-MS/MS: First Action AOAC 2022.06

BACKGROUND

Chlorate is an effective herbicide, but also a byproduct of chlorinating agents used to disinfect water, which is one of the reasons why it is regularly found in food. Perchlorate is a ubiquitous contaminant, which is naturally occurring in the environment but also released from anthropogenic sources such as the industrial use of certain natural fertilizers. Chlorate affects the hematological system, and perchlorate the thyroid.

OBJECTIVE

Implement and validate a simple and robust analytical method for the accurate determination of chlorate and perchlorate in baby food, infant and adult formulas, and ingredients thereof, which is suited for its application in routine environments where a broad variety of food commodities must be analyzed simultaneously.

METHOD

Typically, analytes are extracted with a mixture of water, acidified methanol, and dichloromethane. Optionally, for dairy products and byproducts, extraction can be performed with water, acidified methanol, and EDTA, followed by two steps of cleanup (freezing out and dispersive solid-phase extraction with C18 in acetonitrile). Quantitative determination is carried out by isotopic dilution liquid chromatography tandem mass spectrometry (LC-MS/MS).

RESULTS

The method was single-laboratory validated in five Nestlé Quality Assurance Centers (NQACs) in a comprehensive range of representative matrixes of different categories such as baby foods, infant/adult formulas, and ingredients, with results generally in agreement with the acceptance criteria of the Standard Method Performance Requirement (SMPR®) 2021.001 defined by AOAC INTERNATIONAL, in terms of representative matrixes validated, LOQs, trueness, and precision.The data generated during validation show that the method proposed is simple, accurate and robust enough to be implemented and applied in routine environments.

CONCLUSION

The data generated during validation show that the method proposed is simple, accurate and robust enough to be implemented and applied in routine environments.

HIGHLIGHTS

The AOAC Expert Review Panel approved the present method as AOAC Official First Action 2022.06.

Towards sustainable Cleaning-in-Place (CIP) in dairy processing: Exploring enzyme-based approaches to cleaning in the Cheese industry

Cleaning-in-place (CIP) is the most commonly used cleaning and sanitation system for processing lines, equipment, and storage facilities such as milk silos in the global dairy processing industry. CIP employs thermal treatments and nonbiodegradable chemicals (acids and alkalis), requiring appropriate neutralization before disposal, resulting in sustainability challenges. In addition, biofilms are a major source of contamination and spoilage in dairy industries, and it is believed that current chemical CIP protocols do not entirely destroy biofilms. Use of enzymes as effective agents for CIP and as a more sustainable alternative to chemicals and thermal treatments is gaining interest. Enzymes offer several advantages when used for CIP, such as reduced water usage (less rinsing), lower operating temperatures resulting in energy savings, shorter cleaning times, and lower costs for wastewater treatment. Additionally, they are typically derived from natural sources, are easy to neutralize, and do not produce hazardous waste products. However, even with such advantages, enzymes for CIP within the dairy processing industry remain focused mainly on membrane cleaning. Greater adoption of enzyme-based CIP for cheese industries is projected pending a greater knowledge relating to cost, control of the process (inactivation kinetics), reusability of enzyme solutions, and the potential for residual activity, including possible effects on the subsequent product batches. Such studies are essential for the cheese industry to move toward more energy-efficient and sustainable cleaning solutions.

Isolation and identification of chlorate-reducing Hafnia sp. from milk

Chlorate has become a concern in the food and beverage sector, related to chlorine sanitizers in industrial food production and water treatment. It is of particular concern to regulatory bodies due to the negative health effects of chlorate exposure. This study investigated the fate of chlorate in raw milk and isolated bacterial strains of interest responsible for chlorate breakdown. Unpasteurized milk was demonstrated to have a chlorate-reducing capacity, breaking down enriched chlorate to undetectable levels in 11 days. Further enrichment and isolation using conditions specific to chlorate-reducing bacteria successfully isolated three distinct strains of Hafnia paralvei. Chlorate-reducing bacteria were observed to grow in a chlorate-enriched medium with lactate as an electron donor. All isolated strains were demonstrated to reduce chlorate in liquid medium; however, the exact mechanism of chlorate degradation was not definitively identified in this study.

Chlorate Levels in Dairy Products Produced and Consumed in Ireland

In recent years, chlorate has become a residue of concern internationally, due to the risk that it poses to thyroid gland function. However, little is known about its occurrence in dairy products of Irish origin. To address this, a study was conducted in which samples of milk (n = 317), cream (n = 199), butter (n = 178), cheese (n = 144) and yoghurt (n = 440) were collected from grocery stores in the Republic of Ireland. Sampling was conducted across spring, summer, autumn and winter of 2021. Samples from multiple manufacturers of each respective dairy product were procured and analysed for chlorate using UPLC-MS/MS. Chlorate was detected in milk, cream, natural, blueberry, strawberry and raspberry yoghurts. Mean chlorate levels detected in these products were 0.0088, 0.0057, 0.055, 0.067, 0.077 and 0.095 mg kg^-1, respectively. Chlorate was undetected in butter and cheese (<0.01 mg kg^-1). All products sampled, except yoghurt, were found to be compliant with the EU limit for chlorate in milk (0.10 mg kg^-1). Some manufacturers produced product with greater incidence and levels of chlorate. Chlorate levels from samples tested at different times of the year did not differ significantly, with the exception of strawberry and raspberry yoghurts which had higher chlorate levels in the winter period.

Risk assessment related to the presence of benzalkonium chloride (BAC), didecyldimethyl ammonium chloride (DDAC) and chlorates in fish and fish products

In compliance with Article 31 of Regulation (EC) No 178/2002, EFSA received a mandate from the European Commission to prepare a statement on the risk assessment related to the presence of benzalkonium chloride (mixture of alkylbenzyldimethylammonium chlorides with alkyl chain lengths of C8, C10, C12, C14, C16 and C18) (BAC), didecyldimethylammonium chloride (mixture of alkyl-quaternary ammonium salts with alkyl chain lengths of C8, C10 and C12) (DDAC) and chlorates in fish and fish products. Within EFSA's annual chemical data collection, EFSA collected monitoring data for the residues of BAC, DDAC and chlorates from EU Member States, Iceland and Norway performed a statistical evaluation, providing estimated residue values for each substance in/on fish and fish products, at the percentile appropriate for the number of the available samples. Based on the information collected, EFSA performed an acute and chronic exposure assessment for EU consumers for BAC, DDAC and chlorates at the lower-bound, medium-bound and upper-bound scenarios resulting from the consumption of fish and fish products. EFSA did not identify potential consumer health risks associated to residues of the substances found in fish and fish products.

Kinetic Role of Reactive Intermediates in Controlling the Formation of Chlorine Dioxide in the Hypochlorous Acid-Chlorite Ion Reaction

An advanced experimental protocol is reported for studying the kinetics and mechanism of the complex redox reaction between chlorite ion and hypochlorous acid under acidic condition. The formation of ClO₂ is followed directly by the classical two-component stopped-flow method. In sequential stopped-flow experiments, the target reaction is chemically quenched using NaI solution and the concentration of each reactant and product is monitored as a function of time by utilizing the principles of kinetic discrimination. Thus, in contrast to earlier studies, not only the formation of one of the products but the decay of the reactants was also directly followed. This approach provides a firm basis for postulating a detailed mechanism for the interpretation of the experimental results under a variety of conditions. The intimate details of the reaction are explored by simultaneously fitting 78 kinetic traces, i.e., the concentration vs. time profiles of ClO₂^-, HOCl, and ClO₂, to an 11-step kinetic model. The most important reaction steps were identified, and it was shown that two reactive intermediates have a pivotal role in the mechanism. While chlorate ion predominantly forms via the reaction of Cl₂O, chlorine dioxide is exclusively produced in reaction steps involving Cl₂O₂. This study leads to clear conclusions on how to control the stoichiometry of the reaction and achieve optimum conditions to produce chlorine dioxide and to reduce the formation of the toxic chlorate ion in practical applications.

Preparation and Synergy of Supported Ru0 and Pd0 for Rapid Chlorate Reduction at pH 7

Chlorate (ClO₃^-) is a common water pollutant due to its gigantic scale of production, wide applications in agriculture and industry, and formation as a toxic byproduct in various water treatment processes. This work reports on the facile preparation, mechanistic elucidation, and kinetic evaluation of a bimetallic catalyst for highly active ClO₃^- reduction into Cl^-. Under 1 atm H₂ and 20 °C, Pd^II and Ru^III were sequentially adsorbed and reduced on a powdered activated carbon support, affording Ru⁰-Pd⁰/C from scratch within only 20 min. The Pd⁰ particles significantly accelerated the reductive immobilization of Ru^III as >55% dispersed Ru⁰ outside Pd⁰. At pH 7, Ru-Pd/C shows a substantially higher activity of ClO₃^- reduction (initial turnover frequency >13.9 min^-1 on Ru⁰; rate constant at 4050 L h^-1 g_metal^-1) than reported catalysts (e.g., Rh/C, Ir/C, Mo-Pd/C) and the monometallic Ru/C. In particular, Ru-Pd/C accomplished the reduction of concentrated 100 mM ClO₃^- (turnover number > 11,970), whereas Ru/C was quickly deactivated. In the bimetallic synergy, Ru⁰ rapidly reduces ClO₃^- while Pd⁰ scavenges the Ru-passivating ClO₂^- and restores Ru⁰. This work demonstrates a simple and effective design for heterogeneous catalysts tailored for emerging water treatment needs.

Analysis of Chlorate in Chemical Leavening Agents Used for Bakery Products by Liquid Chromatography-Mass Spectrometry

Chlorate is a food contaminant that is mainly attributed to the use of chlorinated water and disinfectants. The present study investigated if chlorate could also occur as a process contaminant in chemical leavening agents for baking products. Thus, a sensitive and rapid ultrahigh-performance liquid chromatography-tandem mass spectrometry method was developed and validated. Chlorate was quantified using an isotopically labeled internal standard after complete degassing of carbonate-based products. The limit of detection/limit of quantification was 0.02 and 0.1 mg/kg, respectively, with recovery rates between 97.0 and 101.2% (concentration levels: 0.3, 1.4, or 5.0 mg/kg). Samples of baking powder, sodium bicarbonate, ammonium bicarbonate, and potassium carbonate were analyzed. Chlorate was detected in all samples of baking powder in concentrations of 0.23-1.87 mg/kg. Potassium carbonate contained the highest chlorate levels, with a maximum of 60.9 mg/kg. These results indicate that baking powder and, particularly, potassium carbonate can be relevant sources of chlorate in food.

Evaluation of calcium hydroxide, calcium hypochlorite, peracetic acid, and potassium bicarbonate as citrus fruit sanitizers

Xanthomonas citri (X. citri) is a quarentenary plant pathogen and the causal agent of the citrus canker. X. citri forms biofilms and remains fixed on the surface of plant tissues, especially on leaves and fruits. Considering this, all the citrus fruits have to be sanitized before they can be commercialized. NaOCl is the main sanitizer used to decontaminate fruits in the world. Due to its toxicity, treatment with NaOCl is no longer accepted by some Europe Union countries. Therefore, the aim of this work was to evaluate potassium bicarbonate (KHCO₃), calcium hydroxide (Ca(OH)₂), calcium hypochlorite (Ca(OCl)₂) and peracetic acid (CH₃CO₃H) as alternatives to NaOCl for the sanitization of citrus fruit. By monitoring cell respiration and bacterial growth, we determined that peracetic acid and calcium hypochlorite exhibit bactericidal action against X. citri. Time-response growth curves and membrane integrity analyses showed that peracetic acid and calcium hypochlorite target the bacterial cytoplasmatic membrane, which is probably responsible for cell death in the first minutes of contact. The simulation of the sanitization process of citrus fruit in packinghouses showed that only peracetic acid exhibited a performance comparable to NaOCl. Among the tested compounds, peracetic acid constitutes an efficient and safer alternative to NaOCl.

Fresh-Cut Vegetables Processing: Environmental Sustainability and Food Safety Issues in a Comprehensive Perspective

The fresh-cut industry supplies the food market with healthy fresh fruit and vegetables and, in that way, may contribute to improve the nutritional status of the general population. On the other hand, over the last few years increasing concerns have been raised regarding the environmental impact of the fresh-cut industry, human health risks from exposure to disinfection by-products found in fresh-cut products and chlorine-based disinfection treatments during produce processing. This review provides a comprehensive view of the main interlinked aspects related to food safety and environmental impact of processing of fresh-cut vegetables. Advantages and downsides of the mainstream disinfection strategy, based on the use of chlorine-related disinfecting agents, along with some alternative treatments close to a wide commercial application, are discussed. Limitation in the application of these strategies to processing of organic fresh-cut produce are also highlighted, examining the specific environmental and food safety problems in the organic sector. Areas where lack of available information hinders at present a clear understanding of priorities of research and action are pointed out. Innovative conceptual tools are proposed to address these multiple and interlinking issues and to overcome limitations of currently available technologies. A comprehensive and multidisciplinary approach is suggested to move toward a more safe and environmentally sustainable production of fresh-cut products.

Pesticide active substances that do not require a review of the existing maximum residue levels under Article 12 of Regulation (EC) No 396/2005

Regulation (EC) No 396/2005 establishes the rules governing the setting and the review of pesticide maximum residue levels (MRLs) at European level. According to Article 12(1) of Regulation (EC) No 396/2005, EFSA shall provide within 12 months from the date of the inclusion or non‐inclusion of an active substance in Annex I to Directive 91/414/EEC a reasoned opinion on the review of the existing MRLs for that active substance. Article 12(2) of that Regulation stipulates that EFSA shall provide by 1 September 2009 a reasoned opinion on the review of the existing MRLs for all active substances included in Annex I to Directive 91/414/EEC before 2 September 2008. Among the active substances that need to be reviewed under Article 12(1) or Article 12(2) of Regulation (EC) No 396/2005, EFSA identified 6 active substances for which a review of MRLs is no longer considered necessary. EFSA prepared a statement explaining the reasons why a review of MRLs for these substances became obsolete. The relevant question numbers are considered addressed by this statement.

Impact of Electrolyzed Water on the Microbial Spoilage Profile of Piedmontese Steak Tartare

A low initial contamination level of the meat surface is the sine qua non to extend the subsequent shelf life of ground beef for as long as possible. Therefore, the short- and long-term effects of a pregrinding treatment with electrolyzed water (EW) on the microbiological and physicochemical features of Piedmontese steak tartare were here assessed on site, by following two production runs through storage under vacuum packaging conditions at 4°C. The immersion of muscle meat in EW solution at 100 ppm of free active chlorine for 90 s produced an initial surface decontamination with no side effects or compositional modifications, except for an external color change that was subsequently masked by the grinding step. However, the initially measured decontamination was no longer detectable in ground beef, perhaps due to a quick recovery by bacteria during the grinding step from the transient oxidative stress induced by the EW. We observed different RNA-based metataxonomic profiles and metabolomic biomarkers (volatile organic compounds [VOCs], free amino acids [FAA], and biogenic amines [BA]) between production runs. Interestingly, the potentially active microbiota of the meat from each production run, investigated through operational taxonomic unit (OTU)-, oligotyping-, and amplicon sequence variant (ASV)-based bioinformatic pipelines, differed as soon as the early stages of storage, whereas microbial counts and biomarker dynamics were significantly distinguishable only after the expiration date. Higher diversity, richness, and abundance of Streptococcus organisms were identified as the main indicators of the faster spoilage observed in one of the two production runs, while Lactococcus piscium development was the main marker of shelf life end in both production runs. IMPORTANCE Treatment with EW prior to grinding did not result in an effective intervention to prolong the shelf life of Piedmontese steak tartare. Our RNA-based approach clearly highlighted a microbiota that changed markedly between production runs but little during the first shelf life stages. Under these conditions, an early metataxonomic profiling might provide the best prediction of the microbiological fate of each batch of the product.

Sunlight-Driven Chlorate Formation during Produce Irrigation with Chlorine- or Chloramine-Disinfected Water

The increasing use of chlorine- or chloramine-containing irrigation waters to minimize foodborne pathogens is raising concerns about the formation and uptake of disinfection byproducts into irrigated produce. Chlorate has received particular attention in the European Union. While previous research demonstrated the formation of chlorate from dark disproportionation reactions of free chlorine and uptake of chlorate into produce from roots, this study evaluated chlorate formation from solar irradiation of chlorine- and chloramine-containing irrigation droplets and uptake through produce surfaces. Sunlight photolysis of 50 μM (3.6 mg/L as Cl₂) chlorine significantly enhanced the formation of chlorate, with a 7.2% molar yield relative to chlorine. Chlorate formation was much less significant in sunlit chloramine solutions. In chlorinated solutions containing 270 μg/L bromide, sunlight also induced the conversion of bromide to 280 μg/L bromate. Droplet evaporation and the resulting increase in chlorine concentrations approximately doubled sunlight-induced chlorate formation relative to that in the bulk solutions in which evaporation is negligible. When vegetables (broccoli, cabbage, chicory, lettuce, and spinach) were sprayed with chlorine-containing irrigation water in a sunlit field, sunlight promoted chlorate formation and uptake through vegetable surfaces to concentrations above maximum residue levels in the European Union. Spraying with chloramine-containing waters in the dark minimized chlorate formation and uptake into the vegetables.

Raw Milk Microbiota Modifications as Affected by Chlorine Usage for Cleaning Procedures: The Trentingrana PDO Case

Milk microbiota represents a key point in raw milk cheese production and contributes to the development of typical flavor and texture for each type of cheese. The aim of the present study was to evaluate the influence of chlorine products usage for cleaning and sanitizing the milking equipment on (i) raw milk microbiota; (ii) the deriving whey-starter microbiota; and (iii) Trentingrana Protected Designation of Origin (PDO) cheese microbiota and volatilome. Milk samples from three farms affiliated to a Trentingrana PDO cheese factory were collected three times per week during a 6-weeks period in which a sodium hypochlorite detergent (period C) was used and during a subsequent 6-weeks period of non-chlorine detergent usage (period NC). Samples were subjected to microbiological [Standard Plate Count; coliforms; coagulase-positive staphylococci; and lactic acid bacteria (LAB)] and metagenomic analysis (amplification of V3-V4 regions of 16S rRNA gene performed on Illumina MiSeq platform). In addition, cheese volatilome was determined by SPME-GC-MS. In the transition from period C to period NC, higher SPC and LAB counts in milk were recorded. Milk metagenomic analysis showed a peculiar distinctive microbiota composition for the three farms during the whole experimental period. Moreover, differences were highlighted comparing C and NC periods in each farm. A difference in microbial population related to chlorine usage in bulk milk and vat samples was evidenced. Moreover, chlorine utilization at farm level was found to affect the whey-starter population: the usually predominant Lactobacillus helveticus was significantly reduced during NC period, whereas Lactobacillus delbrueckii had the exact opposite trend. Alpha- and beta-diversity revealed a separation between the two treatment periods with a higher presence of L. helveticus, L. delbrueckii, and Streptococcus thermophilus in cheese samples after NC detergent period. Cheese volatilome analysis showed a slight decrease in lipolysis during C period in the inner part of the cheese wheel. Although preliminary, these results suggest a profound influence on milk and cheese microbiota, as well as on raw milk cheese production and quality, due to the use of chlorine. However, further studies will be needed to better understand the complex relationship between chlorine and microbiota along all the cheese production steps.

Distribution and Chemical Fate of [36Cl]Chlorine Dioxide Gas on Avocados, Eggs, Onions, and Sweet Potatoes

Fate and distribution studies were conducted with [³⁶Cl]-chlorine dioxide in avocados, eggs, onions, and sweet potatoes. Experiments utilized sealed, darkened chambers, 5 mg of ³⁶ClO₂ (g), and two-hour exposure periods. Total radioactive residues were quantitated in gas purges, tank rinses, reaction chambers, and on fractions specific to each food. Deposition of the radioactive residue was mostly a surface phenomenon; transfer of radioactivity into albumen occurred in egg, but radioactivity did not penetrate the onion tunic and only small amounts of activity were present in avocado flesh. Potato skin contained essentially all the potato radiochlorine. Regardless of the food product, nearly all radioactive residue was present in edible tissues as chloride ions; the chlorite ion was present only in egg-rinse water. Small amounts (10% or less) of radioactivity were present as chlorate ions, which would be a useful marker compound for chlorine dioxide sanitation.

Preservative Effect of Novel Combined Treatment with Electrolyzed Active Water and Lysozyme Enzyme to Increase the Storage Life of Vacuum-Packaged Carp

In the present study, common carp (Cyprinus carpio), a highly valuable worldwide commercial fish species, was used as a model. One sample group of fresh, skin-on carp fillets was placed in a bath of acidic electrolyzed oxidizing (AEO) water containing a solution of 100 mg/kg chloride ion concentration for 5 minutes. Another sample group was treated with acidic electrolyzed water and 0.5% lysozyme enzyme solution. Another set of samples were washed after the AEO water treatment. Within the study, a storage test was performed to examine the effect of the new combined treatment on the samples’ shelf-life and quality while kept at 2°C. During the storage period, chemical (chlorate) and microbiological (TVC, mesophilic anaerobic plate count, and Enterobacteriaceae count) tests and sensory evaluation were conducted. The combination of AEO water and lysozyme enzyme showed additional bactericidal efficacy on the surface of the carp fillets, which has never been reported before. Both the AEO water and the combined treatment effectively increased the shelf life of the samples, causing 2.4–3.1 log CFU/g difference compared to the control by the end of the 7-day storage. The measured residual chlorate content exceeded the legal threshold, but washing the samples resulted in values below the theoretical threshold limit. The applied preservation methods did not have an adverse effect on the organoleptic properties of the samples.

Towards a dietary-exposome assessment of chemicals in food: An update on the chronic health risks for the European consumer

An informed opinion to a hugely important question, whether the food on the Europeans' plate is safe to eat, is provided. Today, the Europeans face food-borne health risks from non-communicable diseases induced by excess body weight, outbreaks caused by pathogens, antimicrobial resistance and exposures to chemical contaminants. In this review, these risks are first put in an order of importance. Then, not only potentially injurious dietary chemicals are discussed but also beneficial factors of the food. This review can be regarded as an attempt towards a dietary-exposome evaluation of the chemicals, the average European adult consumers could chronically expose to during their life-times. Risk ranking reveals that currently the European adults are chronically exposed to a mixture of potentially genotoxic-carcinogenic contaminants, particularly food process contaminants, at the potential risk levels. Furthermore, several of the contaminants whose dietary exposures pose risks appear to be carcinogens operating with a genotoxic mode of action targeting the liver. This suggests that combined health risks from the exposure to a mixture of the chemical contaminants poses a greater potential risk than the risks assessed for single compounds. Over 100 European-level risk assessments are examined. Finally, the importance of a diversified and balanced diet is emphasized.

Distribution, Identification, and Quantification of Residues after Treatment of Ready-To-Eat Salami with 36Cl-Labeled or Nonlabeled Chlorine Dioxide Gas

When ready-to-eat salami was treated in a closed system with ³⁶Cl-labeled ClO₂ (5.5 mg/100 g of salami), essentially all radioactivity was deposited onto the salami. Administered ³⁶ClO₂ was converted to ³⁶Cl-chloride ion (>97%), trace levels of chlorate (<2%), and detectable levels of chlorite. In residue studies conducted with nonlabeled ClO₂, sodium perchlorate residues (LOQ, 4 ng/g) were not formed when reactions were protected from light. Sodium chlorate residues were present in control (39.2 ± 4.8 ng/g) and chlorine dioxide treated (128 ± 31.2 ng/g) salami. If sanitation occurred under conditions of illumination, detectable levels (3.7 ± 1.5 ng/g) of perchlorate were formed along with greater quantities of sodium chlorate (183.6 ± 75.4 ng/g). Collectively, these data suggest that ClO₂ is chemically reduced by salami and that slow-release formulations might be appropriate for applications involving the sanitation of ready-to-eat meat products.

Assessing the potential impact on the thyroid axis of environmentally relevant food constituents/contaminants in humans

Occurrence and mode of action of potentially relevant goitrogens in human nutrition and their mode of action (MOA) are reviewed, with special focus on the anionic iodine uptake inhibitors perchlorate (PER), thiocyanate (SCN) and nitrate (NO3). Epidemiological studies suggest persistent halogenated organic contaminants and phthalates as well as certain antimicrobials to deserve increased attention. This also applies to natural goitrogens, including polyphenols and glucosinolates, food constituents with limited data density concerning human exposure. Glucosinolates present in animal feed are presumed to contribute to SCN transfer into milk and milk products. PER, SCN and NO3 are well-investigated environmental goitrogens in terms of MOA and relative potency. There is compelling evidence from biomarker monitoring that the exposure to the goitrogens SCN and NO3 via human nutrition exceeds that of PER by orders of magnitude. The day-to-day variation in dietary intake of these substances (and of iodide) is concluded to entail corresponding variations in thyroidal iodide uptake, not considered as adverse to health or toxicologically relevant. Such normal variability of nutritional goitrogen uptake provides an obvious explanation for the variability in radioactive iodine uptake (RAIU) measurements observed in healthy individuals. Based on available data, a 20 % change in the thyroidal uptake of iodide is derived as threshold value for a biologically meaningful change induced by perchlorate and other goitrogens with the same MOA. We propose this value to be used as the critical effect size or benchmark response in benchmark dose analysis of human RAIU data. The resulting BMDL20 is 0.0165 mg/kg bw/day or 16.5 μg/kg bw/day. Applying a factor of 4, to allow for inter-human differences in toxicokinetics, leads to a TDI for perchlorate of 4 μg/kg bw/day.