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The global carbon dioxide in the atmosphere is predicted to rise due to fossil fuel emissions during the next century. Carbon dioxide is soluble in water and partially dissociates into bicarbonate and carbonate, releasing protons that decrease the pH. This change in pH is expected to play a critical role in some earth systems, such as the hydrosphere, where ocean acidification affects the survival of marine organisms. This study used aqueous solutions consisting of water with sodium bicarbonate, Miller's lysogeny broth, Roswell Park Memorial Institute 1640 medium, and Dulbecco's Modified Eagle Medium to develop a colourimetric method for the quantification of dissolved carbon dioxide. Various environmental testing conditions were studied using a fluorescent microplate spectrophotometer. The temperature varied between 27 and 42 °C, and the carbon dioxide levels ranged from 0.20 to 10% v/v in the air. The data showed that the amount of dissolved carbon dioxide decreased by 50% in broth solutions, while the reduction in water samples was approximately 18% when the temperature rose from 27 to 42 °C. Furthermore, the composition of the solutions impacted the amount of gas dissolved. The highest amount of dissolved carbon dioxide was observed in the water sample with the lowest salinity, which reached 20,000 ppm CO2 at 27 °C. The lowest amount of dissolved carbon dioxide concentrations was obtained in Miller's lysogeny broth with the highest salinity level, which reached 1200 ppm under the same conditions. The results obtained can be considered a robust estimation method to calculate the amount of dissolved carbon dioxide under different conditions. [ABSTRACT FROM AUTHOR]

A plasma source, sustained by the application of a floating high voltage (±15 kV) to parallel-plate electrodes at 50 Hz, has been achieved in a helium/air mixture at atmospheric pressure (P = 105 Pa) contained in a zip-locked plastic package placed in the electrode gap. Some of the physical and antimicrobial properties of this apparatus were established with a view to ascertain its performance as a prototype for the disinfection of fresh produce. The current-voltage (I-V) and charge-voltage (Q-V) characteristics of the system were measured as a function of gap distance d, in the range (3 × 10³ = Pd = 1.0 × 104 Pa m). The electrical measurements showed this plasma source to exhibit the characteristic behaviour of a dielectric barrier discharge in the filamentary mode and its properties could be accurately interpreted by the two-capacitance in series model. The power consumed by the discharge and the reduced field strength were found to decrease quadratically from 12.0 W to 4.5 W and linearly from 140 Td to 50 Td, respectively, in the range studied. Emission spectra of the discharge were recorded on a relative intensity scale and the dominant spectral features could be assigned to strong vibrational bands in the 2+ and 1- systems of N2 and N2+, respectively, with other weak signatures from the NO and OH radicals and the N+, He and O atomic species. Absolute spectral intensities were also recorded and interpreted by comparison with the non-equilibrium synthetic spectra generated by the computer code SPECAIR. At an inter-electrode gap of 0.04 m, this comparison yielded typical values for the electron, vibrational and translational (gas) temperatures of (4980 ± 100) K, (2700 ± 200) K and (300 ± 100) K, respectively and an electron density of 1.0 × 1017 m-3. A Boltzmann plot also provided a value of (3200 ± 200 K) for the vibrational temperature. The antimicrobial efficacy was assessed by studying the resistance of both Escherichia coli K12 its isogenic mutants in soxR, soxS, oxyR, rpoS and dnaK selected to identify possible cellular responses and targets related with 5 min exposure to the active gas in proximity of, but not directly in, the path of the discharge filaments. Both the parent strain and mutants populations were significantly reduced by more than 1.5 log cycles in these conditions, showing the potential of the system. Post-treatment storage studies showed that some transcription regulators and specific genes related to oxidative stress play an important role in the E. coli repair mechanism and that plasma exposure affects specific cell regulator systems. [ABSTRACT FROM AUTHOR]

To investigate the effect of the oxidative stress of ozone on the microbial inactivation, cell membrane integrity and permeability and morphology changes of Escherichia coli. Escherichia coli BW 25113 and its isogenic mutants in soxR, soxS, oxyR, rpoS and dnaK genes were treated with ozone at a concentration of 6 μg ml for a period up to 240 s. A significant effect of ozone exposure on microbial inactivation was observed. After ozonation, minor effects on the cell membrane integrity and permeability were observed, while scanning electron microscopy analysis showed slightly altered cell surface structure. The results of this study suggest that cell lysis was not the major mechanism of microbial inactivation. The deletion of oxidative stress-related genes resulted in increased susceptibility of E. coli cells to ozone treatment, implying that they play an important role for protection against the radicals produced by ozone. However, DnaK that has previously been shown to protect against oxidative stress did not protect against ozone treatment in this study. Furthermore, RpoS was important for the survival against ozone. This study provides important information about the role of oxidative stress in the responses of E. coli during ozonation. [ABSTRACT FROM AUTHOR]

Traditionally, ozone processing within the food industry has focused on solid foods by either gaseous treatment or washing with ozonized water. However, with the FDA's approval of ozone as a direct additive to food, the potential for liquid applications has emerged. This study investigates the effect of ozone processing on microbial inactivation ( E. coli ATCC 25922 and NCTC 12900) and quality parameters (color, phenolic content) of cloudy apple juice. Apple juice samples were ozonated at room temperature (20 ± 1.5 °C) with a generated ozone concentration of 0.048 mg O at a constant flow rate of 0.12 L/min and treatment time of 0 to 10 min. E. coli inactivation kinetics in apple juice were described quantitatively by using the Shoulder log-linear and the Weibull model. Ozone treatment of E. coli in apple juice demonstrate that a desired 5 log reduction can be achieved within 5 min. Apple juice color ( L*, a*, and b*) and total phenols were significantly affected by ozone concentration and treatment time. [ABSTRACT FROM AUTHOR]

The large potential of cold atmospheric plasma (CAP) for food decontamination has recently been recognized. Room-temperature gas plasmas can decontaminate foods without causing undesired changes. This innovative technology is a promising alternative for treating fresh produce. However, more fundamental studies are needed before its application in the food industry. The impact of the food structure on CAP decontamination efficacy of Salmonella Typhimurium and Listeria monocytogenes was studied. Cells were grown planktonically or as surface colonies in/onmodel systems. Both microorganismswere grown in lab culturemedia in petri dishes at 20 ?C until cells reached the stationary phase. Before CAP treatment, cellswere deposited in a liquid carrier, on a solid(like) surface or on a filter. A dielectric barrier discharge reactor generated helium-oxygen plasma, which was used to treat samples up to 10 min. Although L. monocytogenes is more resistant to CAP treatment, similar trends in inactivation behavior as for S. Typhimurium are observed, with log reductions in the range [1.0-2.9] for S. Typhimurium and [0.2-2.2] for L. monocytogenes. For both microorganisms, cells grown planktonically are easily inactivated, as compared to surface colonies. More stressing growth conditions, due to cell immobilization, result in more resistant cells during CAP treatment. The main difference between the inactivation support systems is the absence or presence of a shoulder phase. For experiments in the liquid carrier, which exhibit a long shoulder, the plasma components need to diffuse and penetrate through the medium. This explains the higher efficacies of CAP treatment on cells deposited on a solid(like) surface or on a filter. This research demonstrates that the food structure influences the cell inactivation behavior and efficacy of CAP, and indicates that food intrinsic factors need to be accounted when designing plasma treatment. [ABSTRACT FROM AUTHOR]

Cold atmospheric plasma (CAP) is a non-thermal decontamination technology capable of generating groups of antimicrobial agents including; photons, electrons, positively and negatively charged ions, atoms, free radicals and excited or non-excited molecules. CAP treatments (70 kV, 50 Hz) at different times (i.e. 15, 30, 60, 90 s) were applied to a broth system inoculated either with Escherichia coli NCTC 12900, E. coli ME 9062 or E. coli knockout mutants of soxS, rpoS and dnaK genes. Optical emission spectra were performed and the main antimicrobial reactive substances generated by CAP treatments were found to be N2, N2+, NO, Hα and He. After treatments, reduction levels of the studied bacteria were up to 0.5 log CFU/mL, no showing statistical differences. Moreover, the kinetic growth parameters were calculated by applying the 2-fold dilution method. μmax decreased in all bacteria when the time of CAP treatment increased. E. coli dnaK was the most sensitive mutant to plasma, showing no recovery after CAP of 60 and 90 s. In addition, CAP challenge test treatments were applied on butter head lettuce inoculated with E. coli NCTC 12900 with CAP treatments of 60 and 90 s reducing bacteria levels by more than 1.5 log CFU/cm2. [ABSTRACT FROM AUTHOR]

Liquid egg products are typically exposed to a defined thermal load to achieve the required safety level, under which their functional properties can be adversely affected. In this study, manothermosonication (MTS) (132 μm, 300 kPa) was investigated as alternative preservation for liquid whole egg (LWE) compared to thermal pasteurisation (60 °C, 3.5 min), assessing results against untreated (fresh) LWE in terms of selected physico-chemical properties. Results showed that MTS resulted in improved LWE foaming properties, increasing foam capacity by a 3.2-fold factor compared to thermal treatment. Emulsion stability was also enhanced after MTS, exhibiting smaller droplet size, and a higher elasticity of gels was obtained. Regarding the protein properties, favourable protein changes (protein unfolding) were identified for MTS through direct (asymmetric flow field flow fractionation) and indirect (surface hydrophobicity and sulfhydryl group content) measurements. In addition, an increase in protein solubility of 11.4 % was observed in MTS compared to thermal treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In the current study, the synthesis of hydroxyapatite-ceria (HAP-CeO 2 ) scaffolds is attempted through a bioinspired chemical approach. The utilized colloidal CeO 2 suspension presents antifungal activity against the Aspergillus flavus and Aspergillus fumigatus species at concentrations higher than 86.1 ppm. Three different series of the composite HAP-CeO 2 suspensions are produced, which are differentiated based on the precursor suspension to which the CeO 2 suspension is added and by whether this addition takes place before or after the formation of the hydroxyapatite phase. Each of the series consists of three suspensions, in which the pure ceria weight reaches 4, 5, and 10% (by mass) of the produced hydroxyapatite, respectively. The characterization showed that the 2S series's specimens present the greater alteration towards their viscoelastic properties. Furthermore, the 2S series's sample with 4% CeO 2 presents the best mechanical response. This is due to the growth of needle-like HAP crystals during lyophilization, which-when oriented perpendicular to the direction of stress application-enhance the resistance of the sample to deformation. The 2S series's scaffolds had an average pore size equal to 100 μm and minimum open porosity 89.5% while simultaneously presented the lowest dissolution rate in phosphate buffered saline.

Cereal grains serve as the cornerstone of global nutrition, providing a significant portion of humanity's caloric requirements. However, the presence of fungal genera, such Fusarium , Penicillium , Aspergillus , and Alternaria , known for their mycotoxin-producing abilities, presents a significant threat to human health due to the adverse effects of these toxins. The primary objective of this study was to identify the predominant fungal contaminants in cereal grains utilized in breadmaking, as well as in flour and bread. Moreover, a systematic review, including meta-analysis, was conducted on the occurrence and levels of mycotoxins in wheat flour from the years 2013 to 2023. The genera most frequently reported were Fusarium , followed by Penicillium , Aspergillus , and Alternaria . Among the published reports, the majority focused on the analysis of Deoxynivalenol (DON), which garnered twice as many reports compared to those focusing on Aflatoxins, Zearalenone, and Ochratoxin A. The concentration of these toxins, in most cases determined by HPLC-MS/MS or HPLC coupled with a fluorescence detector (FLD), was occasionally observed to exceed the maximum limits established by national and/or international authorities. The prevalence of mycotoxins in flour samples from the European Union (EU) and China, as well as in foods intended for infants, exhibited a significant reduction compared to other commercial flours assessed by a meta-analysis investigation.

Ultrasound (US) technology is recognized as one of the emerging technologies that arise from the current trends for improving nutritional and organoleptic properties while providing food safety. However, when applying the US alone, higher power and longer treatment times than conventional thermal treatments are needed to achieve a comparable level of microbial inactivation. This results in risks, damaging food products' composition, structure, or sensory properties, and can lead to higher processing costs. Therefore, the US has often been investigated in combination with other approaches, like heating at mild temperatures and/or treatments at elevated pressure, use of antimicrobial substances, or other emerging technologies (e.g., high-pressure processing, pulsed electric fields, nonthermal plasma, or microwaves). A combination of US with different approaches has been reported to be less energy and time consuming. This manuscript aims to provide a broad review of the microbial inactivation efficacy of US technology in different food matrices and model systems. In particular, emphasis is given to the US in combination with the two most industrially viable physical processes, that is, heating at mild temperatures and/or treatments at elevated pressure, resulting in techniques known as thermosonication, manosonication, and manothermosonication. The available literature is reviewed, and critically discussed, and potential research gaps are identified. Additionally, discussions on the US's inactivation mechanisms and lethal effects are included. Finally, mathematical modeling approaches of microbial inactivation kinetics due to US-based processing technologies are also outlined. Overall, this review focuses only on the uses of the US and its combinations with other processes relevant to microbial food decontamination., (© 2023 The Authors. Comprehensive Reviews in Food Science and Food Safety published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

Iron-based biodegradable metal bone graft substitutes are in their infancy but promise to fill bone defects that arise after incidents such as trauma and revision arthroplasty surgery. Before clinical use however, a better understanding of their in vivo biodegradability, potential cytotoxicity and biocompatibility is required. In addition, these implants must ideally be able to resist infection, a complication of any implant surgery. In this study there was significant in vitro cytotoxicity caused by pure Fe, FeMn, FeMn1Ag and FeMn5Ag on both human foetal osteoblast (hFOB) and mouse pre-osteoblast (MC3T3-E1) cell lines. In vivo experiments on the other hand showed no signs of ill-effect on GAERS rats with the implanted FeMn, FeMn1Ag and FeMn5Ag pins being removed largely uncorroded. All Fe-alloys showed anti-bacterial performance but most markedly so in the Ag-containing alloys, there is significant bacterial resistance in vitro ., Competing Interests: The authors declare that they have no competing interests., (© 2023 The Authors.)

The growth behavior of Listeria monocytogenes low population (1-4 cells/sample) on fresh-cut mango, melon, papaya and fruit mix stored at 4, 8, 12 and 16 °C was evaluated over 10 days. Mango showed the lowest counts for L. monocytogenes during 10 days regardless of storage temperature (<1.7 log cfu.g -1 ). Melon supported high bacterial growth over 10 days, reaching 5 log cfu.g -1 at 16 °C. Both the fruit and storage temperature influenced the Listeria low population growth potential (δ). Cumulative frequency distribution of L. monocytogenes showed that after 10 days, 100% of fresh-cut fruits and fruit mix stored at 4 °C remained ≤2 log cfu.g -1 , while at 12 and 16 °C 100% of melon, papaya and fruit mix samples exceeded this limit. At 8 °C, 100% of mango and fruit mix samples remained below this limit after 10 days, whereas 100% of melon and papaya reached it after 7 days. Results indicate 4 °C as the ideal to store safely fresh-cut mango, melon, papaya and fruit mix for 10 days. Besides, 8 °C can also be an option, but not for melon and papaya. Findings highlight the ability of L. monocytogenes to survive and grow in fresh-cut fruits even at a very low initial population levels., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Abstract: Nanotechnology has developed into one of the most groundbreaking scientific fields in the last few decades because it exploits the enhanced reactivity of materials at the atomic scale. The current classification of nanoparticles (NPs) used in foods is outlined in relation to the production and physicochemical characteristics. This review aims to concisely present the most popular and widely used inorganic and organic NPs in food industries. Considering that the toxicity of NPs is often associated with chemical reactivity, a series of in vitro toxicity studies are also summarized, integrating information on the type of NP studies and reported specifications, type of cells used, exposure conditions, and assessed end points. The important role of the digestive system in the absorption and distribution of nanoformulated foods within the body and how this affects the resultant cytotoxicity. Examples of how NPs and their accumulation within different organs are presented in relation to the consumption of specific foods. Finally, the role of developing human health risk assessments to characterize both the potential impact of the hazard and the likelihood or level of human exposure is outlined. Uncertainties exist around risk and exposure assessments of NPs due to limited information on several aspects, including toxicity, behavior, and bioaccumulation. Overall, this review presents current trends and needs for future assessments in toxicity evaluation to ensure the safe application of NPs in the food industry., (Copyright ©, International Association for Food Protection.)

Aims: Alicyclobacillus acidoterrestris is a sporulating, acidophilic bacterial species which spoils acidic beverages such as fruit juices. This work aims to quantify the heat resistance of A. acidoterrestris spores and their recovery potential as a function of heating and recovery media pH., Methods and Results: The heat treatments were carried out with the strain of A. acidoterrestris Ad 746 in Bacillus acidoterrestris thermophilic medium. The pH of the heating medium from pH 7 to pH 2 nonsignificantly reduced the heat resistance. However, the pH levels of the recovery media strongly affected the apparent heat resistance of this strain. The maximum heat resistance was found when the pH was 4·70 and decreased when the pH decreased to pH 2·8, close to the minimum growth pH and when the recovery medium pH increased to pH 5·3., Conclusion: The heating medium pH has a slight effect on the spore heat resistances of this acidophilic species. However, the pH of the recovery media strongly affected the apparent heat resistance of this strain., Significance and Impact of the Study: The obtained parameters quantifying the heat resistance of A. acidoterrestris spores are tools to optimize the heat treatments and to control its development., (© 2020 The Society for Applied Microbiology.)

Highly concentrated sugar solutions are known to be effective antimicrobial agents. However, it is unknown whether this effect is solely the result of the collective osmotic effect imparted by a mixture of sugars or whether the type of carbohydrate used also has an individual chemical effect on bacterial responses, that is, inhibition/growth. In view of this, in this work, the antimicrobial properties of four sugars, namely, glucose, fructose, sucrose and maltose against three common food pathogens; Staphylococcus aureus, Escherichia coli and Salmonella enterica, were investigated using a turbidimetric approach. The results obtained indicate that the type of sugar used has a significant effect on the extent of bacterial inhibition which is not solely dependent on the water activity of the individual sugar solution. In addition, while it was shown that high sugar concentrations inhibit bacterial growth, very low concentrations show the opposite effect, that is, they stimulate bacterial growth, indicating that there is a threshold concentration upon which sugars cease to act as antimicrobial agents and become media instead. SIGNIFICANCE AND IMPACT OF THE STUDY: In this work, an analysis on the antimicrobial properties of glucose, fructose, sucrose and maltose in solution was conducted using a turbidimetric approach. Our findings indicate that while, as expected, all of these sugars exhibit significant antimicrobial effects at high concentrations, at low concentrations they appear to act as substrates for the bacteria which results in enhanced microbial growth instead of inhibition. In addition, the results obtained also suggest that the resultant osmotic stress imparted by the sugar solutions is not the only factor which determines their antimicrobial activity and that other chemical factors may be playing a significant role., (© 2020 The Society for Applied Microbiology.)

The identification and quantification of phenolic compounds and flavonoids in various natural food products is typically conducted using HPLC analysis. Their analysis is particularly complex since most natural food products contain a large number of different phenolic compounds, many of which have similar chemical characteristics such as polarity, which makes complete separation of all eluents extremely difficult. In this work we present and validate a method for the quantitative determination of the concentration of two compounds with similar retention times, i.e. they show overlapping peaks in a mixed solution. Two pairs of phenolic compounds were investigated: caffeic and vanillic acids and ferulic and p -coumaric acids. This technique takes advantage of the different absorbances of the two phenolic compounds in the eluent at various wavelengths and can be used for the quantitative determination of the concentration of these compounds even if they are not separated in the HPLC column. The presented method could be used to interpret the results of HPLC analysis of food products which possess a vast spectrum of phenolic compounds and flavonoids., Competing Interests: CONFLICTS OF INTEREST: The authors declare no conflict of interest.

This study assessed the influence of rpoS, dps and ompR genes on the tolerance response of Salmonella Enteritidis 86 (SE86) to homologous and heterologous stressing agents after exposure to essential oils (EOs) from Origanum vulgare L. (oregano; OVEO) and Rosmarinus officinalis L. (rosemary; ROEO) and their major constituents (ICs), carvacrol (CAR) and 1,8-cineole (CIN), respectively, by modelling the log reduction over time. Minimum inhibitory concentration values of OVEO (1.25 μL/mL), CAR (0.62 μL/mL), ROEO (20 μL/mL) and CIN (10 μL/mL) against SE86 were always one-fold higher than those against ∆dps, ∆rpoS and ∆ompR mutants. Exposure to the same concentration of OVEO, CAR, ROEO or CIN caused higher reductions (up to 2.5 log CFU/mL) in ∆dps, ∆rpoS and ∆ompR mutants than in SE86 in chicken broth. In assays with homologous stressing agents, ompR, dps and rpoS influenced the tolerance to OEs or ICs. After adaptation to OVEO, CAR, ROEO and CIN, osmotolerance and acid tolerance of SE86 were influenced by rpoS gene, while thermotolerance of SE86 was influenced by ompR. Tolerance of SE86 to sodium hypochlorite after adaptation to OEs or ICs was influenced by rpoS and dps. These findings quantitatively describe for the first time the influence of rpoS, dps and ompR genes on the tolerance of Salmonella Enteritidis to OVEO, CAR, ROEO and CIN., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Coupling microbial dynamics with the complete dynamics of the packaging gases is still a challenge. In this work the microbial growth kinetic parameters for Pseudomonas and Lactic Acid Bacteria (LAB) in MAP are identified based on accurate estimation of diffusivity of gases and parameter scaled sensitivity approaches. The microbial dynamics are also compared with those estimated based on partial pressure measurement. Scaled sensitivity coefficient analysis using dissolved gases as variable inputs, shows that in most cases the only coefficients large enough for estimation were those for CO 2max-diss , and for μ max . The current data showed that dissolved gases led significant differences on the microbial parameter of CO 2max values when compared with the headspace gases. On the other hand, the (so-called) dissolved specific growth rate follows a clear trend down for both microorganisms in relation to the increase of the initial headspace CO 2 . Finally, current results indicate a possible correlation between CO 2max-diss , CO 2max-headspace , and μ max as functions of CO 2init ., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose: Dental prosthetic and orthodontic appliances are transported from the clinic to the laboratory for additions and repairs. These appliances, containing microbes from the oral flora, are a high risk for cross-contamination. The aim of this study was to evaluate the effect of chemical and ultrasound disinfection against two in vitro biofilms and an in vivo formed biofilm grown on unprepared and polished polymethyl methacrylate (PMMA) surfaces., Materials and Methods: Rough and polished self-curing PMMA surfaces were infected with strains of both Candida albicans and Streptococcus oralis. After incubation, the samples were treated with different disinfection methods, including ultrasound treatment for both 15 and 30 seconds, and immersion in glutaraldehyde and alcohol-based chemical disinfectants (MD520 and Minuten, respectively). The disinfecting efficacy was assessed by colony forming units (CFU) analysis and by scanning electron microscopy (SEM). Furthermore the adequacy of bacterial elimination of application of 30-second ultrasound and MD520 was assessed on PMMA retrieved from ten volunteers by CFU analyses. ANOVA with p = 0.05 followed by the Tukey post hoc test and the Student t-test was used to analyze the data., Results: The ultrasound treatment for 30 seconds, MD520, and Minuten were the most effective disinfectant methods as they reduced the microbial counts compared to the control (p < 0.05) as shown in the in vitro analyses. S. oralis adhered more to rough acrylic resin surfaces (p < 0.05). Ultrasound treatment was the most effective way to reduce microbial counts on PMMA exposed to oral flora (p = 0.043)., Conclusion: Ultrasound treatment for 30 seconds was effective against C. albicans, S. oralis, and the oral flora as shown by testing microbial growth on agar plates and SEM., (© 2016 by the American College of Prosthodontists.)

Aims: Foods and drinks are major contributors (17%) to the greenhouse gas (GHG) emissions caused by private consumption in Europe. The carbon footprint (CF) of a certain product expresses the total GHG emissions over its whole life cycle, and its calculation for foodstuff is a necessary first step to reduce their contribution to global warming. The calculation of the CF of Maltese food products is especially relevant for two reasons: the economic characteristics of the island, whose food sector is highly dependent on imports, implying longer transport distances; and the Maltese electricity production mix, based almost exclusively on oil combustion., Methods and Results: The CF of ten multi-fruit juices marketed in Malta has been determined, covering all the processes from the agricultural stage to the distribution of the final products. As a functional unit (FU), a 250 ml bottle of packaged product arriving at the retailer has been considered. The Maltese orange juice, the only final product in which only local ingredients are used, presents the lowest CF (0.50 kgCO 2 /FU), while the remaining ones range from 0.67 kgCO 2 /FU to 0.80 kgCO 2 /FU. The major contributor to all the CFs is juice processing at the Maltese plant (0.42 kgCO 2 /FU), mainly due to the use of electricity (78%)., Conclusions: The influence of both the electricity mix and the Maltese supply chain in the CF of the final products has been demonstrated. Alternatives to reduce the impacts of the final products have been proposed and evaluated that could lower the average CF of the juices by 32%., Significance and Impact of the Study: The calculation of the CF of Maltese juices represents an innovative case study due to the characteristics of the island, and it is expected to act as a first step to lower their environmental impacts., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Ultrasound creates cavitation phenomena, resulting in the formation of several free radicals, namely OH˙ and H˙, due to the breakdown of the H 2 O molecule. These radicals affect the cellular integrity of the bacteria, causing the inactivation of several processes, and thus it is important to unravel the mechanism of action of this technology. This research looks into the application and mechanism of action of ultrasound technology as a means of disinfection by acoustic cavitation. Sterile water and synthetic waste water were inoculated with different mutants of Escherichia coli K12 strains containing deletions in genes affecting specific functional properties of E. coli. These were: dnak soxR, soxS, oxyR, rpoS, gadA/gadB, gadC and yneL. Escherichia coli K-12 ΔoxyR appeared to be more resistant to the treatment together with gadW, gadX, gabT and gabD, whereas the mutant K-12 ΔdnaK was more sensitive with c. 2·5 log (CFU per ml) reduction in comparison to their isogenic wild-type E. coli K-12. This indicates that the dnaK gene participates in general stress response and more specifically to hyperosmotic stress. The other E. coli deleted genes tested (soxS, rpoS, gadB, gadC, yneL) did not appear to be involved in protection of microbial cells against ultrasound., Significance and Impact of the Study: This study looks at the mechanism of action of ultrasound technology for the disinfection of wastewater. Different mutants with deleted genes were used to study the respective sensitivity or resistance to this treatment. This is essential to characterize changes at the molecular level, which might be occurring during treatment, resulting in bacterial adaptation., (© 2017 The Society for Applied Microbiology.)

Bacillus sporothermodurans produces highly heat-resistant endospores, that can survive under ultra-high temperature. High heat-resistant sporeforming bacteria are one of the main causes for spoilage and safety of low-acid foods. They can be used as indicators or surrogates to establish the minimum requirements for heat processes, but it is necessary to understand their thermal inactivation kinetics. The aim of the present work was to study the inactivation kinetics under both static and dynamic conditions in a vegetable soup. Ordinary least squares one-step regression and sequential procedures were applied for estimating these parameters. Results showed that multiple dynamic heating profiles, when analyzed simultaneously, can be used to accurately estimate the kinetic parameters while significantly reducing estimation errors and data collection., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Purpose: The aim of this study was to assess the antimicrobial activity of chemical disinfectants on alginate and silicone impression materials. The effect of chemical disinfectants on the dimensional stability of the impression materials was also assessed., Materials and Methods: For the microbiologic assessment, impressions of the maxillary arch were taken from 14 participants, 7 using alginate and 7 using an addition silicone. The impressions were divided into three sections. Each section was subjected to spraying with MD 520 or Minuten or no disinfection (control), respectively. Antimicrobial action of the chemical disinfectants was assessed by measuring microbial counts in trypticase soy agar (TSA) media and expressing the results in colony-forming units/cm2. The surface area of the dental impressions was calculated by scanning a stone cast using computer-aided design/computer-assisted manufacture and analyzing the data using a custom computer program. The dimensional stability of the impression materials after immersion in disinfectants was assessed by measuring the linear displacement of horizontally restrained materials using a traveling microscope. The percent change in length over 3 hours was thus determined., Results: Alginate exhibited a higher microbial count than silicone. MD 520 eliminated all microbes as opposed to Minuten. The bacterial growth after Minuten disinfection was almost twice as much for alginate than for addition silicone impressions. The chemical disinfectants affected the alginate dimensional stability. Minuten reduced the shrinkage sustained by alginate during the first hour of storage., Conclusions: Alginate harbors three times more microorganisms than silicone impression material. Chemical disinfection by glutaraldehyde-based disinfectant was effective in eliminating all microbial forms for both alginate and silicone without modifying the dimensional stability. Alcohol-based disinfectants, however, reduced the alginate shrinkage during the first 90 minutes of setting. The current studies also propose another method to report the surface area based on accurate estimation by 3D image analysis.

Objectives: The aim of this study was to investigate any changes to the microstructure and surface properties of selected dental materials after sterilization carried out prior to subjecting them to antimicrobial testing. Initial microbial contamination on the material, as well as other possible sources of contamination were also assessed., Methods: The materials investigated included dentine replacement materials Chemfil Superior(®), Ionoseal(®), Dyract Extra(®) and SDR(®). The materials were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The test materials were sterilized using alcohol, steam, ultraviolet light (UV) and ethylene oxide and any changes to these materials were then assessed by SEM, microhardness testing and Fourier transform infrared (FT-IR) spectroscopy. Material microbial levels before treatments were assessed by plate counting technique and turbidity tests. Possible contamination through dispensers was assessed by analysing the CFU/sample., Results: Ethylene oxide affected the microstructure of the Chemfil, Ionoseal and Dyract, resulting in flattening of the SiO stretching vibrations and deposition of chlorine and calcium respectively in Chemfil and Dyract. Varied contamination was demonstrated on all materials when incubated in anaerobic conditions., Conclusions: The different sterilization techniques affected the microstructure of the materials under investigation. Samples of materials produced in sterile conditions could also be contaminated with bacteria, either from the material itself or through the dispensing apparatus., Clinical Significance: Results of antimicrobial studies cannot be extrapolated clinically as the material sterilization treatment results in changes to material chemistry and microstructure, which could in turn affect the materials' antimicrobial activity., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Hyperspectral chemical imaging (HSI) is a broad term encompassing spatially resolved spectral data obtained through a variety of modalities (e.g. Raman scattering, Fourier transform infrared microscopy, fluorescence and near-infrared chemical imaging). It goes beyond the capabilities of conventional imaging and spectroscopy by obtaining spatially resolved spectra from objects at spatial resolutions varying from the level of single cells up to macroscopic objects (e.g. foods). In tandem with recent developments in instrumentation and sampling protocols, applications of HSI in microbiology have increased rapidly. This article gives a brief overview of the fundamentals of HSI and a comprehensive review of applications of HSI in microbiology over the past 10 years. Technical challenges and future perspectives for these techniques are also discussed., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This research investigated the efficacy of gaseous ozone on the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in apple juice of a range of pH levels, using an ozone bubble column. The pH levels investigated were 3.0, 3.5, 4.0, 4.5 and 5.0. Apple juice inoculated with E. coli strains (10(6)CFU/mL) was treated with ozone gas at a flow rate of 0.12L/min and ozone concentration of 0.048 mg/min/mL for up to 18 min. Results show that inactivation kinetics of E. coli by ozone were affected by pH of the juice. The ozone treatment duration required for achieving a 5-log reduction was faster (4 min) at the lowest pH than at the highest pH (18 min) studied. The relationship between time required to achieve 5log reduction (t(5d)) and pH for both strains was described mathematically by two exponential equations. Ozone treatment appears to be an effective process for reducing bacteria in apple juice and the required applied treatment for producing a safe apple juice is dependant on its acidity level., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Many of the documented outbreaks of Cronobacter sakazakii have been linked to infant formula. The aims of this work are to monitor the inactivation kinetics of C.sakazakii NCTC 08155 and ATCC 11467 and to determine quantitatively the effectiveness of ultrasonic treatments as an alternative to heat processing of reconstituted infant milk formula before feeding of infants at highest risk. Inactivation studies of C. sakazakii inoculated in reconstituted infant formula were performed at the combined conditions of temperature, i.e., 25 degrees C, 35 degrees C, 50 degrees C and amplitude, i.e., 24.4, 30.5, 42.7, 54.9, 61 microm and the kinetics were described by a range of inactivation models. The dependency of the specific inactivation rate with respect to the product of temperature and amplitude was described by a modified Bigelow type model. Ultrasound combined with temperature was efficient to reduce significantly the microbial levels of C. sakazakii. C. sakazakii strain NCTC 08155 was at the same range of temperature and amplitude resistance as strain ATCC 11467. Application of ultrasound is an alternative process for the production of safe reconstituted infant formula. This study contributes on the quantitative assessment of the resistance of C. sakazakii., (Copyright 2010 Elsevier B.V. All rights reserved.)

In this study dynamic microbial inactivation experiments are exploited for performing parameter identification of a non-linear microbial model. For that purpose microbial inactivation data are produced and a differential equation exhibiting a shoulder and a loglinear phase is employed. The derived parameter estimates from this method were used to perform predictions on an independent experimental set at fluctuating temperature. Joint confidence regions and asymptotic confidence intervals of the estimated parameters were compared with previous studies originating from parameter identification under isothermal conditions. The developed approach can provide more reliable estimates for realistic conditions compared to the usual or standard two step approach.

This contribution focuses on the presentation of GInaFiT (Geeraerd and Van Impe Inactivation Model Fitting Tool), a freeware Add-in for Microsoft Excel aiming at bridging the gap between people developing predictive modelling approaches and end-users in the food industry not familiar with or not disposing over advanced non-linear regression analysis tools. More precisely, the tool is useful for testing nine different types of microbial survival models on user-specific experimental data relating the evolution of the microbial population with time. As such, the authors believe to cover all known survivor curve shapes for vegetative bacterial cells. The nine model types are: (i) classical log-linear curves, (ii) curves displaying a so-called shoulder before a log-linear decrease is apparent, (iii) curves displaying a so-called tail after a log-linear decrease, (iv) survival curves displaying both shoulder and tailing behaviour, (v) concave curves, (vi) convex curves, (vii) convex/concave curves followed by tailing, (viii) biphasic inactivation kinetics, and (ix) biphasic inactivation kinetics preceded by a shoulder. Next to the obtained parameter values, the following statistical measures are automatically reported: standard errors of the parameter values, the Sum of Squared Errors, the Mean Sum of Squared Errors and its Root, the R(2) and the adjusted R(2). The tool can help the end-user to communicate the performance of food preservation processes in terms of the number of log cycles of reduction rather than the classical D-value and is downloadable via the KULeuven/BioTeC-homepage at the topic "Downloads" (Version 1.4, Release date April 2005).

This research deals with the development of a novel secondary modelling procedure within the framework of predictive microbiology. The procedure consists of three steps: (i) careful formulation of the available microbiological information, both from literature and from the experimental case study at hand, (ii) translation of these requirements in mathematical terms under the form of partial derivatives throughout the complete interpolation region of the experimental design, and (iii) determination of parameter values with suitable optimisation techniques for a flexible black box modelling approach, e.g., a polynomial model or an artificial neural network model. As a vehicle for this procedure, the description of the maximum specific growth rate of Lactobacillus sakei in modified BHI-broth as influenced by suboptimal temperature, water activity, sodium lactate and dissolved carbon dioxide concentration is under study. The procedure results in a constrained polynomial model with excellent descriptive and interpolating features in comparison with an extended Ratkowsky-type model and classical polynomial model, by combining specific properties of both model types. The developed procedure is illustrated on the description of the lag phase as well. It is stressed how the confrontation with experimental data is very important to appreciate the descriptive and interpolating capacities of new or existing models, which is nowadays not always carefully performed. Alternatively, the first two steps of the novel procedure can be used as a tool to demonstrate clearly (possible) interpolative shortcomings of an existing model with straightforward spreadsheet calculations.