Category Archives: Technology

Research – Effects of Thermally-Assisted and High-Pressure Processing on Background Microbiota and the Listeria monocytogenes Load of a Minimally Processed Commodity

Posted on September 16, 2024 by | Leave a comment

MDPI

Abstract

The current study investigated the impact of treatments with elevated hydrostatic pressure (500 MPa) for inactivation of Listeria monocytogenes on smoked rainbow trout (Oncorhynchus mykiss) at high and low inoculation levels. The temperature values of the trials were set at 4.4 and 60.0 °C, adjusted with a circulating water bath connected to a stainless steel jacket surrounding the pressure processing chamber. Before pressure processing, the counts (selective counts of PALCAM, mean ± SD) of L. monocytogenes were 6.45 ± 0.1 log CFU/g and were reduced (p < 0.05) to 3.72 ± 0.3, and <1.48 ± 0.8 log CFU/g after 10 min of treatment at 4.4 and 60.0 °C, respectively. Treatments of low inoculation level samples were similarly efficacious and resulted in a reduction (p < 0.05) of the pathogen to 1.62 ± 0.3 and <0.82 ± 0.0 log CFU/g for treatments at 4.4 and 60.0 °C, respectively. At 4.4 °C, linear D-value and non-linear kmax1 were 8.68 and 0.50, and 5.81 and 2.41 for high-inoculation and low-inoculation samples, respectively. Application of hydrostatic pressure at 500 MPa at cold and elevated temperatures was efficacious for up to 5.03 log CFU/g reduction of L. monocytogenes, illustrating the potential for further adaptation of this technology.

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Posted in Food Microbiology Research, Food Technology, High Pressure, Listeria, Listeria monocytogenes, Research, Technology

Research – Salmonella Inactivation Model by UV-C Light Treatment in Chicken Breast

Posted on September 2, 2024 by | Leave a comment

MDPI

Abstract

This study aims to evaluate the effectiveness of inactivating Salmonella enteritidis in fresh chicken breast by irradiation using a combination of short-wave UV (0, 3, 6, 9, 12, and 15 J/cm2) and a natural antimicrobial such as caffeine (0, 5, 10, 15, and 20 nM/g) at 14 °C as alternative proposals to conventional techniques to reduce pathogens in food. The effect of temperature was studied in an initial phase (2 to 22 °C). The most suitable models were double Weibull in 60% of cases, with an adjustment of R2 0.9903–0.9553, and Weibull + tail in 46.67%, with an adjustment of R2 of 0.9998–0.9981. The most effective combination for the reduction in Salmonella was 12 J/cm2 of UV light and 15 nM/g of caffeine, with a reduction of 6 CFU/g and an inactivation rate of 0.72. The synergistic effect was observed by increasing caffeine and UV light. Furthermore, the physico-chemical characteristics of the food matrix were not affected by the combination of both technologies. Therefore, these results suggest that this combination can be used in the food industry to effectively inactivate Salmonella enteritidis without deteriorating product quality.

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Posted in Food Microbiology Research, Food Technology, Research, Salmonella, Technology, UV Microbiology, UV-C

Research – Innovative Hurdle Strategies for Listeria Control on Food-Contact Surfaces: A Peroxyacetic Acid–Steam Approach

Posted on August 23, 2024 by | Leave a comment

MDPI

Abstract

The persistence of Listeria monocytogenes biofilms on equipment surfaces poses a significant risk of cross-contamination, necessitating effective surface decontamination strategies. This study assessed the effectiveness of hurdle treatments combining peroxyacetic acid (PAA) and saturated steam against 7-day-old L. innocua (a non-pathogenic surrogate for L. monocytogenes) biofilms on stainless steel (SS), polyester (PET), and rubber surfaces. Results demonstrated >6 log10 CFU/coupon L. innocua reductions on SS and PET surfaces after PAA (40 ppm, 1 min) followed by steam treatment (100 °C, 6 s). On rubber surfaces, PAA (80 ppm, 1 min) followed by steam treatment (100 °C, 6 s) resulted in ~5 log10 CFU/coupon L. innocua reduction. The presence of apple juice soil reduced the efficacy of hurdle treatments, with PAA (40 ppm, 1 min) and steam exposure (6 s) resulting in 5.6, 5.8, and 4.2 log10 CFU/coupon reductions of L. innocua on SS, PET, and rubber, respectively. The efficacy of this antimicrobial combination was further reduced by surface defects, especially in the presence of organic matter. Nevertheless, the treatment still achieved >5 log10 CFU/coupon reductions of L. innocua on worn SS and PET soiled with apple juice and ~4.5 log10 CFU/coupon reduction on worn, soiled rubber surfaces. These findings highlight that PAA treatments followed by a brief steam exposure are effective strategies for controlling Listeria on food-contact surfaces.

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Posted in Biofilm, Food Microbiology Research, Food Technology, Hurdle Technology, Listeria, Listeria innocua, Listeria monocytogenes, Research, Technology

Research – Persistence of Salmonella and Campylobacter on Whole Chicken Carcasses under the Different Chlorine Concentrations Used in the Chill Tank of Processing Plants in Sri Lanka

Posted on August 22, 2024 by | Leave a comment

MDPI

Abstract

The persistence of non-typhoidal Salmonella and Campylobacter in chicken meat is a considerable public health risk and a future challenge. This study aimed to determine the prevalence of Salmonella and Campylobacter in poultry processing lines where different chlorine concentrations were used in the chill tank. The samples were collected from four types of processing plants in Sri Lanka, considering the chlorine concentration used in the chill tank, which ranged from 2 ppm to 50 ppm. Salmonella and Campylobacter were isolated from whole carcass washings, neck skin, and cecal samples. Subsequently, an antimicrobial susceptibility test was performed for the isolates. The results revealed the overall prevalence of Salmonella and Campylobacter was 78.25% and 63.5%, respectively. Positive percentages of Salmonella and Campylobacter were high in the carcasses compared to the neck skin and ceca. The Campylobacter counts on the whole carcasses were significantly low (p < 0.001), at higher chlorine concentrations ranging from 20 to 30 ppm and 40 to 50 ppm. The pathogen prevalence in the whole carcasses was 84.7% Campylobacter coli, 39.1% Campylobacter jejuni, 71.1% Salmonella Typhimurium, and 28.8% Salmonella Infantis. The highest resistance was observed for tetracycline (63.8%) in Salmonella, while it was for gentamicin (87.8%) in Campylobacter. The prevalence percentage of multidrug-resistant Campylobacter was 51.2%, while it was 2.12% for Salmonella. The persistence of multidrug-resistant Salmonella and Campylobacter on the post-chill carcasses was highlighted in the present study as a significant public health threat that has to be addressed urgently.

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Posted in Antibacterial, Campylobacter, Food Microbiology Research, Food Technology, Research, Salmonella, Technology

Research – Comparative Study of the Antibacterial Effects of S-Nitroso-N-acetylcysteine and Sodium Nitrite against Escherichia coli and Their Application in Beef Sausages

Posted on August 3, 2024 by | Leave a comment

MDPI

Abstract

This study investigated the antibacterial effects of S-nitroso-N-acetylcysteine (SNAC) and sodium nitrite (NaNO2) against Escherichia coli and their application in beef sausages. Both SNAC and NaNO2 demonstrated pH-responsive antibacterial activity, with SNAC showing greater efficacy than NaNO2 (p < 0.05) at the same pH (3, 5, and 7). The reactive oxygen species (ROS) and reactive nitrogen species (RNS) induced in E. coli by SNAC were significantly higher than those induced by NaNO2 (p < 0.05), and both ROS and RNS values increased as the pH decreased. In addition, a lower pH led to more pores on the E. coli cell surface and increased membrane permeability, resulting in a more pronounced inhibitory effect. When applied to a beef sausage, SNAC-treated sausages had significantly lower total colony counts and carbonyl content compared to NaNO2-treated ones (p < 0.05). Consequently, SNAC shows great potential as a replacement for NaNO2 in meat products.

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Posted in Antimicrobials, E.coli, Food Microbiology Research, Food Technology, Research, Technology

Research – Impact of Biotic and Abiotic Factors on Listeria monocytogenes, Salmonella enterica, and Enterohemorrhagic Escherichia coli in Agricultural Soil Extracts

Posted on July 27, 2024 by | Leave a comment

MDPI

Abstract

Outbreaks of Enterohemorrhagic Escherichia coli (EHEC), Salmonella enterica, and Listeria monocytogenes linked to fresh produce consumption pose significant food safety concerns. These pathogens can contaminate pre-harvest produce through various routes, including contaminated water. Soil physicochemical properties and flooding can influence pathogen survival in soils. We investigated survival of EHEC, S. enterica, and L. monocytogenes in soil extracts designed to represent soils with stagnant water. We hypothesized pathogen survival would be influenced by soil extract nutrient levels and the presence of native microbes. A chemical analysis revealed higher levels of total nitrogen, phosphorus, and carbon in high-nutrient soil extracts compared to low-nutrient extracts. Pathogen survival was enhanced in high-nutrient, sterile soil extracts, while the presence of native microbes reduced pathogen numbers. A microbiome analysis showed greater diversity in low-nutrient soil extracts, with distinct microbial compositions between extract types. Our findings highlight the importance of soil nutrient composition and microbial dynamics in influencing pathogen behavior. Given key soil parameters, a long short-term memory model (LSTM) effectively predicted pathogen survival. Integrating these factors can aid in developing predictive models for pathogen persistence in agricultural systems. Overall, our study contributes to understanding the complex interplay in agricultural ecosystems, facilitating informed decision-making for crop production and food safety enhancement.

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Posted in EHEC, Food Microbiology Research, Food Pathogen, Food Technology, Listeria, Listeria monocytogenes, Pathogen, pathogenic, Research, Salmonella, STEC, STEC E.coli, Technology

Research – IAEA helps Cuba with Ciguatoxin problem

Posted on July 21, 2024 by | Leave a comment

Food Safety News

Scientists are helping researchers in Cuba find dangerous toxins in marine algae that can lead to outbreaks from contaminated seafood.

The International Atomic Energy Agency (IAEA) has been building capacity for monitoring ciguatera using nuclear and isotopic techniques to identify seafood biotoxins.

Ciguatoxins are a class of algal toxins. They enter the food chain by consuming Ciguatoxin-containing algae by fish and shellfish and accumulating in larger predatory fish.

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Posted in Algal Blooms, Algal Toxin, Ciguatera, Ciguatera Poisoning, Food Microbiology Research, Food Technology, Research, Technology

Research – Recent Advances in Non-Contact Food Decontamination Technologies for Removing Mycotoxins and Fungal Contaminants

Posted on July 20, 2024 by | Leave a comment

MDPI

Abstract

Agricultural food commodities are highly susceptible to contamination by fungi and mycotoxins, which cause great economic losses and threaten public health. New technologies such as gamma ray irradiation, ultraviolet radiation, electron beam irradiation, microwave irradiation, pulsed light, pulsed electric fields, plasma, ozone, etc. can solve the problem of fungal and mycotoxin contamination which cannot be effectively solved by traditional food processing methods. This paper summarizes recent advancements in emerging food decontamination technologies used to control various fungi and their associated toxin contamination in food. It discusses the problems and challenges faced by the various methods currently used to control mycotoxins, looks forward to the new trends in the development of mycotoxin degradation methods in the future food industry, and proposes new research directions.

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Posted in antifungal, Cold Atmospheric Plasma, Cold Plasma, Food Microbiology Research, Food Technology, fungi, mold, Mold Toxin, Mold/ MouldAscospores, Mould/Mold, Mycotoxin, Ozone, Research, Technology, UV Microbiology

Research – Avoiding Food Poisoning: How a Tiny Chip Can Make Your Food Safer Than Ever

Posted on June 29, 2024 by | Leave a comment

Scitech Daily

A new microfluidic chip developed by researchers enables quick, effective detection of multiple foodborne pathogens simultaneously, improving food safety and preventing contaminated products from entering the market.

Every so often, a food product is recalled because of some sort of contamination. For consumers of such products, a recall can trigger doubt in the safety and reliability of what they eat and drink. In many cases, a recall will come too late to keep some people from getting ill.

In spite of the food industry’s efforts to fight pathogens, products are still contaminated and people still get sick. Much of the problem stems from the tools available to screen for harmful pathogens, which are often not effective enough at protecting the public.

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Posted in Food Microbiology Research, Food Pathogen, Food Technology, Pathogen, pathogenic, Research, Technology

Research – Cold plasma processing for food safety

Posted on June 8, 2024 by | Leave a comment

Food Safety News

 Cold plasma is an emerging food processing technology which has been shown to effectively inactivate pathogenic bacteria, viruses, parasites, and fungi. The process uses high-voltage electricity to ionize air and/or defined gas blends to create a mixture of ions, free electrons, ozone, radical species, and other reactive products. This energetic plasma, which operates near room temperature, has been tested with fruits, vegetables, nuts, meats, cheeses, poultry, seeds, powders, and other foods.

Once created at the high voltage electrodes, the cold plasma is applied to foods and food contact surfaces. Forced air can blow the cold plasma over products and surfaces, as with plasma jet systems. This allows for the varying treatment distances of irregularly shaped foods. The commodity may also be moved in and out of the plasma field, as with dielectric barrier (DBD) systems. In either case, reactive chemical species in the cold plasma break the cellular structures, DNA, and proteins of pathogens on foods, inactivating them. Efficacy is dependent on treatment intensity and duration. Combining cold plasma with chemical sanitizers, high intensity light, or other food safety interventions can provide enhanced, synergistic pathogen inactivation. Short treatments with cold plasma can induce sublethal injury in pathogens, rendering them more susceptible to another sanitizing processes.

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Posted in Cold Atmospheric Plasma, Cold Plasma, Food Microbiology Research, Food Pathogen, Food Technology, Hurdle Technology, Pathogen, pathogenic, Research, Technology