Ferrate (Fe(VI): HFeO4- /FeO42-), a potent oxidant, has been investigated as an alternative chemical disinfectant in water treatment due to its reduced production of disinfection by-products. In this study, we assessed the disinfecting ability of potassium ferrate against a variety of microorganisms, including waterborne pathogens, under varying pH and water temperature conditions. We presented CT values, a metric of ferrate concentrations (C) and contact time (T), to quantify microbial inactivation rates. Among the tested microorganisms, human adenovirus was the least resistant to ferrate, followed by waterborne bacteria such as Escherichia coli and Vibrio cholerae, and finally, the protozoan parasite Giardia duodenalis. We further investigated the impact of two pH values (7 and 8) and two temperatures (5 and 25 °C) on microbial inactivation rates, observing that inactivation rates increased with lower pH and higher temperature. In addition to showcasing ferrate\'s capacity to effectively inactivate a range of the tested microorganisms, we offer a ferrate CT table to facilitate the comparison of the effectiveness of various disinfection methods.

Cronobacter sakazakii is a potentially pathogenic bacterium that is resistant to osmotic stress and low aw, and capable of persisting in a desiccated state in powdered infant milks. It is widespread in the environment and present in various products. Despite the low incidence of cases, its high mortality rates of 40 to 80 % amongst neonates make it a microorganism of public health interest. This current study performed a comparative assessment between current reduction methods applied for C. sakazakii in various food matrices, indicating tendencies and relevant parameters for process optimization. A systematic review and meta-analysis were conducted, qualitatively identifying the main methods of inactivation and control, and quantitatively evaluating the effect of treatment factors on the reduction response. Hierarchical clustering dendrograms led to conclusions on the efficiency of each treatment. Review of recent research trend identified a focus on the potential use of alternative treatments, with most studies related to non-thermal methods and dairy products. Using random-effects meta-analysis, a summary effect-size of 4-log was estimated; however, thermal methods and treatments on dairy matrices displayed wider dispersions - of τ2 = 8.1, compared with τ2 = 4.5 for vegetal matrices and τ2 = 4.0 for biofilms. Meta-analytical models indicated that factors such as chemical concentration, energy applied, and treatment time had a more significant impact on reduction than the increase in temperature. Non-thermal treatments, synergically associated with heat, and treatments on dairy matrices were found to be the most efficient.

High pressure processing (HPP) is a non-thermal technology that can ensure microbial safety without compromising food quality. However, the presence of pressure-resistant sub-populations, the revival of sub-lethally injured (SLI) cells, and the resuscitation of viable but non-culturable (VBNC) cells pose challenges for its further development. The combination of HPP with other methods such as moderate temperatures, low pH, and natural antimicrobials (e.g., bacteriocins, lactate, reuterin, endolysin, lactoferrin, lactoperoxidase system, chitosan, essential oils) or other non-thermal processes (e.g., CO2, UV-TiO2 photocatalysis, ultrasound, pulsed electric fields, ultrafiltration) offers feasible alternatives to enhance microbial inactivation, termed as \"HPP plus\" technologies. These combinations can effectively eliminate pressure-resistant sub-populations, reduce SLI or VBNC cell populations, and inhibit their revival or resuscitation. This review provides an updated overview of microbial inactivation by \"HPP plus\" technologies and elucidates possible inactivation mechanisms.

This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets (Oreochromis niloticus) by fogging (15 min) or by immersion (2 s) in a pool of Escherichia coli (NEWP 0022, ATCC 25922, and a field-isolated strain), Staphylococcus aureus (ATCC 25923 and a field-isolated strain), and Salmonella Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control S. Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding E. coli, there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For S. aureus, only immersion in PA showed no significant difference (p < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing S. Typhimurium, E. coli, and S. aureus in tilapia fillets.

Oxidation-reduction potential (ORP) is commonly used as a rapid measurement of the antimicrobial potential of free chlorine during industrial fresh produce washing. The current study tested the hypothesis that ORP can act as a \"single variable\" measurement of bacterial (vegetative and endospores) inactivation effectiveness with free chlorine irrespective of the water pH value. This situation has on occasion been assumed but never confirmed nor disproven. Chlorine-dosed pH 6.5 and 8.5 phosphate buffer solutions were inoculated with Escherichia coli (E. coli), Listeria innocua (L. innocua), or Bacillus subtilis (B. subtilis) endospores. ORP, free chlorine (FC), and log reduction were monitored after 5 s (for E. coli and L. innocua) and up to 30 min (for B. subtilis spores) of disinfection. Logistic and exponential models were developed to describe how bacteria reduction varied as a function of ORP at different pH levels. Validation tests were performed in phosphate buffered pH 6.5 and 8.5 cabbage wash water periodically dosed with FC, cabbage extract and a cocktail of Escherichia coli O157:H7 (E. coli O157:H7) and Listeria monocytogenes (L. monocytogenes). The built logistic and exponential models confirmed that at equal ORP values, the inactivation of the surrogate strains was not consistent across pH 6.5 and pH 8.5, with higher reductions at higher pH. This is the opposite of the well-known free chlorine-controlled bacterial inactivation, where the antibacterial effect is higher at lower pH. The validation test results indicated that in the cabbage wash water, the relationship between disinfection efficiency and ORP was consistent with the oxidant demand free systems. The study suggests that ORP cannot serve as a reliable single variable measurement to predict bacterial disinfection in buffered systems. When using ORP to monitor and control the antibacterial effectiveness of the chlorinated wash water, it is crucial to take into account (and control) the pH.

The efficacy of an in-package microbial inactivation method, combining H2O2 and atmospheric dielectric barrier discharge cold plasma (ADCP) treatments (H2O2-ADCP), in reducing contamination of Brassica oleracea (cabbage) slices was investigated. Cabbage slices were placed in a polyethylene terephthalate container with a H2O2-soaked polypropylene pad attached to the inside of the lid, followed by subjecting the closed container to ADCP treatment. The H2O2-ADCP treatment inactivated Escherichia coli O157:H7 and Listeria monocytogenes, resulting in reductions of 1.8 and 2.0 log CFU/g, respectively, which were greater than the sum of the inactivation effects observed with each individual treatment. The combined treatment decreased the count of Bacillus cereus spores and indigenous bacteria by 1.0 log spores/g and 1.3 log CFU/g, respectively. Moreover, the in-package method did not alter the moisture content or texture of cabbage slices. These results demonstrate the potential of H2O2-ADCP as a microbial decontamination method for packaged cabbage slices.

The worldwide market for vegetable and fruit juices stands as a thriving sector with projected revenues reaching to $81.4 billion by 2024 and an anticipated annual growth rate of 5.27% until 2028. Juices offer a convenient means of consuming bioactive compounds and essential nutrients crucial for human health. However, conventional thermal treatments employed in the juice and beverage industry to inactivate spoilage and pathogenic microorganisms, as well as endogenous enzymes, can lead to the degradation of bioactive compounds and vitamins. In response, non-thermal technologies have emerged as promising alternatives to traditional heat processing, with pulsed electric field (PEF) technology standing out as an innovative and sustainable choice. In this context, this comprehensive review investigated the impact of PEF on the microbiological, physicochemical, functional, nutritional, and sensory qualities of vegetable and fruit juices. PEF induces electroporation phenomena in cell membranes, resulting in reversible or irreversible changes. Consequently, a detailed examination of the effects of PEF process variables on juice properties is essential. Monitoring factors such as electric field strength, frequency, pulse width, total treatment time, and specific energy is important to ensure the production of a safe and chemically/kinetically stable product. PEF technology proves effective in microbial and enzymatic inactivation within vegetable and fruit juices, mitigating factors contributing to deterioration while maintaining the physicochemical characteristics of these products. Furthermore, PEF treatment does not compromise the content of substances with functional, nutritional, and sensory properties, such as phenolic compounds and vitamins. When compared to alternative processing methods, such as mild thermal treatments and other non-thermal technologies, PEF treatment consistently demonstrates comparable outcomes in terms of physicochemical attributes, functional properties, nutritional quality, and overall safety.

BACKGROUND: Goat milk is considered a nutritionally superior resource, owing to its advantageous nutritional attributes. Nevertheless, it is susceptible to spoilage and the persistence of pathogens. Electron beam irradiation stands as a promising non-thermal processing technique capable of prolonging shelf life with minimal residue and a high degree of automation.
RESULTS: The effects of electron beam irradiation (2, 3, 5, and 7 kGy) on microorganisms, physicochemical properties, and protein structure of goat milk compared with conventional pasteurized goat milk (PGM) was evaluated. It was found that a 2 kGy electron beam irradiation reduces the total microbial count of goat milk by 6-logs, and the irradiated goat milk protein secondary structure showed a significant decrease in ɑ-helix content. Low irradiation doses led to microaggregation and crosslinking. In contrast, high doses (≥ 5 kGy) slightly disrupted the aggregates and decreased the particle size, disrupting the microscopic surface structure of goat milk, verified by scanning electron microscopy and confocal laser scanning microscopy.
CONCLUSIONS: The irradiation of goat milk with a 2 kGy electron beam may effectively inactivate harmful microorganisms in the milk and maintain/or improve the physicochemical quality and protein structure of goat milk compared to thermal pasteurization. © 2024 Society of Chemical Industry.

In this study, thermosonication (37 KHz, 300 W; 50, 60, and 70 °C) of celery juice was performed to inactivate Escherichia coli and Salmonella Typhi in 6 min. The inactivation of pathogens and the process were modeled using mathematical, thermodynamic, and computational fluid dynamics models. The findings indicated that the distribution of power dissipation density was not uniform across the entire domain, including the beaker area, with a maximum value of 27.8 × 103 W/m3. At lower temperatures, E. coli showed a 9.4 % higher resistance to sonication, while at higher temperatures, S. Typhi had a 5.4 % higher durability than E. coli. Increasing the temperature decreased the maximum inactivation rate of both S. Typhi and E. coli by 15.5 % and 20.5 % respectively, while increasing the thermal level by 20 °C reduced the log time to achieve the maximum inactivation rate by 20.3 % and 34.9 % for S. Typhi and E. coli respectively, highlighting the stronger effect of sonication at higher temperatures. According to the results, the positive magnitudes of ΔG were observed in both E. coli and S. Typhi, indicating a similar range of variations. Additionally, the magnitude of ΔG increased by approximately 5.2 to 5.5 % for both microorganisms which suggested the inactivation process was not spontaneous.

Mycotoxins are common in many agricultural products and may harm both animals and humans. Dietary mycotoxins are reduced via physical, chemical, and thermal decontamination methods. Chemical residues are left behind after physical and chemical treatments that decrease food quality. Since mycotoxins are heat-resistant, heat treatments do not completely eradicate them. Cold plasma therapy increases food safety and shelf life. Cold plasma-generated chemical species may kill bacteria quickly at room temperature while leaving no chemical residues. This research explains how cold plasma combats mold and mycotoxins to guarantee food safety and quality. Fungal cells are damaged and killed by cold plasma species. Mycotoxins are also chemically broken down by the species, making the breakdown products safer. According to a preliminary cold plasma study, plasma may enhance food shelf life and quality. The antifungal and antimycotoxin properties of cold plasma benefit fresh produce, agricultural commodities, nuts, peppers, herbs, dried meat, and fish.