Category Archives: Research

Research – Removal of Ochratoxin A from Grape Juice by Clarification: A Response Surface Methodology Study

Posted on May 21, 2022 by | Leave a comment

MDPI

This study achieved maximum removal of ochratoxin A (OTA) during the grape juice clarification process with minimal reduction in antioxidant compounds (phenolic acid, flavonoids, and antioxidant capacity by FRAP) by the RSM method. Independent variables included three types of clarifiers—gelatin, bentonite, and diatomite (diatomaceous earth)—at a concentration level of 0.25–0.75% and clarification time of 1–3 h. OTA was measured by high-performance liquid chromatography with fluorescence detection. Clarifying agent concentration and clarification time affected the reduction amount of OTA and antioxidant compounds in grape juice. There was a direct linear correlation between the reduction amounts of OTA and antioxidant compounds and capacity with the concentration of bentonite, gelatin, and diatomite, and the clarification time. The reduction amount of OTA and antioxidant capacity followed the linear mode. However, the decreased phenolic acid and flavonoid values followed the quadratic model. The study results showed that if the concentrations of bentonite, gelatin, and diatomite and clarification time were 0.45, 0.62, 0.25%, and 1 h, respectively, the maximum amount of OTA reduction (41.67%) occurred. Furthermore, the phenolic acid, flavonoid, and antioxidant activity decrease amounts were at their lowest levels, i.e., 23.86, 7.20, and 17.27%, respectively. View Full-Text

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, Food Toxin, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Mold Toxin, Mould Toxin, Mycotoxin, Ochratoxin, OTA, Research, Technology, Toxin

Research – Influence of Metal Concentration and Plumbing Materials on Legionella Contamination

Posted on May 21, 2022 by | Leave a comment

MDPI

Legionella colonization of water supply pipes is a significant public health problem. The objective of this work was to evaluate Legionella colonization in hotel hot water systems and to investigate the relationship between metal concentrations, piping materials (galvanized iron pipes and plastic pipes), and Legionella proliferation. Concentrations of calcium and magnesium ions and the presence of Legionella pneumophila were determined in a total of 108 water samples from the hot water systems of four hotels in Split-Dalmatia County over a 12-month period, and additional data on piping materials were collected. L. pneumophila was isolated in 23.1% of all samples—in 28.8% (15/52) of water samples from galvanized iron pipes and in 17.8% (10/56) of samples from plastic pipes. L. pneumophila serogroups 2–14 were isolated from all samples. This study found higher prevalence of L. pneumophila at higher concentrations of Ca and Mg ions (except for Mg and plastic pipes). The metal parts of the water supply may be important factors in Legionella contamination due to the possibility of lime scale or roughness of the pipes. Higher Ca and Mg ion concentrations increased the risk of Legionella colonization. View Full-Text

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Posted in Contaminated water, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Legionella, Legionella anisa, Legionella rubilucens, Legionnaires’ disease, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Water, water microbiology, Water Safety

USA – FDA Issues Final Guidance for Seeds Used for Sprouting

Posted on May 18, 2022 by | Leave a comment

FDA

Constituent Update

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May 13, 2022

Today the U.S. Food and Drug Administration (FDA) issued a final guidance titled “Reducing Microbial Food Safety Hazards in the Production of Seed for Sprouting: Guidance for Industry.” This guidance outlines FDA’s serious concerns over foodborne illness outbreaks associated with the consumption of raw and lightly-cooked sprouts and provides firms with recommended steps to prevent adulteration throughout the production chain of seed for sprouting.

Between 1996 and 2020, there were 52 reported outbreaks of foodborne illness associated with contaminated sprouts, resulting in more than 2,700 cases of illness. Although contamination can occur at any point along the sprout supply chain, seed has historically been, and continues to be, identified as the likely source of contamination in many of these outbreaks. The Produce Safety Rule (PSR) includes sprout-specific requirements for sprout growers. However, we do not consider seed for sprouting to be covered produce under the PSR and, therefore, the growing, conditioning, and distribution of seed for sprouting is not subject to PSR requirements. Although seed used for sprouting is not covered by the PSR, the FDA does consider seed used for sprouting to be food.

The final guidance recommends that everyone in the sprout seed supply chain become as informed as reasonably possible about the food safety practices, processes, and procedures followed by the firm(s) from which they source their seed, where the seed will go after it leaves their firm, and whether their seed is reasonably likely to be used to produce sprouts for human consumption. The final guidance acknowledges that the practices and conditions appropriate for producing seed for sprouting likely will necessitate a higher level of food safety precautions compared to practices and conditions for producing seed that will be used for other purposes.

Consistent with the draft guidance published in June 2019, this final guidance recommends that seed for sprouting be grown using Good Agricultural Practices or in conformance with international standards such as the Codex Alimentarius International Code of Hygienic Practice for Fresh Fruits and VegetablesExternal Link Disclaimer. In addition, this guidance clarifies that testing should not be used in place of GAPs or Codex standards.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Safety, Food Safety Alert, Food Safety Management, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Water Safety

Research – An Exploration of Listeria monocytogenes, Its Influence on the UK Food Industry and Future Public Health Strategies

Posted on May 18, 2022 by | Leave a comment

MDPI

Listeria monocytogenes is a Gram-positive intracellular pathogen that can cause listeriosis, an invasive disease affecting pregnant women, neonates, the elderly, and immunocompromised individuals. Principally foodborne, the pathogen is transmitted typically through contaminated foods. As a result, food manufacturers exert considerable efforts to eliminate L. monocytogenes from foodstuffs and the environment through food processing and disinfection. However, L. monocytogenes demonstrates a range of environmental stress tolerances, resulting in persistent colonies that act as reservoirs for the reintroduction of L. monocytogenes to food contact surfaces and food. Novel technologies for the rapid detection of L. monocytogenes and disinfection of food manufacturing industries have been developed to overcome these obstacles to minimise the risk of outbreaks and sporadic cases of listeriosis. This review is aimed at exploring L. monocytogenes in the UK, providing a summary of outbreaks, current routine microbiological testing and the increasing awareness of biocide tolerances. Recommendations for future research in the UK are made, pertaining to expanding the understanding of L. monocytogenes dissemination in the UK food industry and the continuation of novel technological developments for disinfection of food and the food manufacturing environment View Full-Text

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – Penn State microbiologists receive USDA grant to study biofilms guarding Listeria

Posted on May 15, 2022 by | Leave a comment

Food Safety News

The U.S. Department of Agriculture has awarded a $605,000 grant to microbiologists in Penn State’s College of Agricultural Sciences to study how microbial biofilms protect Listeria monocytogenes.

“Microorganisms enclosed in a biofilm produce slimy substances that protect them from the antimicrobial activity of sanitizing chemicals by slowing down their penetration into the core of a biofilm,” Jasna Kovac, Lester Earl and Veronica Casida Career Development Professor of Food Safety and Assistant Professor of Food Science said.

“Biofilm formation can therefore result in reduced efficacy of antimicrobial sanitizers used to inactivate Listeria. This project will investigate the interactions between microorganisms found in fruit-packing environments and Listeria monocytogenes.”

Along with Kovac, Luke LaBorde, professor of Food Science, will use the funding from USDA’s National Institute of Food and Agriculture to conduct research on the interactions between microorganisms found in fruit-packing environments and Listeria monocytogenes.

According to LaBorde, because the role of the food-processing environment microbiota on Listeria monocytogenes survival within a biofilm under sanitizer pressure is poorly understood, the researchers will evaluate the ability of the most relevant environmental microbiota found in produce-packing environments to form single- and multi-species biofilms with Listeria monocytogenes.

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Posted in Biofilm, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – IAFNS presents new research on pathogens and low-moisture foods

Posted on May 15, 2022 by | Leave a comment

Food Safety News

New research on hazards in low-moisture foods fills critical knowledge gaps and identifies cutting-edge decontamination tools. The Institute for the Advancement of Food and Nutrition Sciences hopes the study will empower food safety professionals to reduce risks in the foods and prevent foodborne illness outbreaks.

Because the persistence of pathogens and viruses in ingredients and ready-to-eat foods has wide-ranging impacts on our food supply, the Institute for the Advancement of Food and Nutrition Sciences (IAFNS) is supporting a body of research on this topic. The studies focus on low-moisture foods such as nuts, dried fruits, cereal products and chocolate. These foods are often ingrediates in other foods, so they can potentially amplify outbreaks and recalls over a wide variety of products, according to researchers.

These studies were performed as part of a multi-center research collaboration between the University of Guelph, Health Canada and North Carolina State University. This collaboration enabled the investigators’ diverse perspectives and expertise to strengthen this line of research.

According to Jeff Farber of the University of Guelph, “the increased awareness of the importance of low-moisture foods (LMF) as a possible vehicle for foodborne illness has already led to better approaches toward prevention and control and will continue to do so in the future.”

Read More at the link above.

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Posted in Decontamination Microbial, Food Illness, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Foodborne Illness, Illness, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – Recent Developments in Botulinum Neurotoxins Detection

Posted on May 15, 2022 by | Leave a comment

MDPI

kswfoodworld

Botulinum neurotoxins (BoNTs) are produced as protein complexes by bacteria of the genus Clostridium that are Gram-positive, anaerobic and spore forming (Clostridium botulinum, C. butyricum, C. baratii and C. argentinense spp.). BoNTs show a high immunological and genetic diversity. Therefore, fast, precise, and more reliable detection methods are still required to monitor outbreaks and ensure surveillance of botulism. The botulinum toxin field also comprises therapeutic uses, basic research studies and biodefense issues. This review presents currently available detection methods, and new methods offering the potential of enhanced precision and reproducibility. While the immunological methods offer a range of benefits, such as rapid analysis time, reproducibility and high sensitivity, their implementation is subject to the availability of suitable tools and reagents, such as specific antibodies. Currently, the mass spectrometry approach is the most sensitive in vitro method for a rapid detection of active or inactive forms of BoNTs. However, these methods require inter-laboratory validation before they can be more widely implemented in reference laboratories. In addition, these surrogate in vitro models also require full validation before they can be used as replacement bioassays of potency. Cell-based assays using neuronal cells in culture recapitulate all functional steps of toxin activity, but are still at various stages of development; they are not yet sufficiently robust, due to high batch-to-batch cell variability. Cell-based assays have a strong potential to replace the mouse bioassay (MBA) in terms of BoNT potency determination in pharmaceutical formulations; they can also help to identify suitable inhibitors while reducing the number of animals used. However, the development of safe countermeasures still requires the use of in vivo studies to complement in vitro immunological or cell-based approaches. View Full-Text

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Posted in Bacterial Toxin, Clostridium, Clostridium botulinum, Food Microbiology Research, Food Microbiology Testing, Food Toxin, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Toxin

Research – Inactivation of Foodborne Pathogens on Inshell Walnuts by UV-C Radiation

Posted on May 15, 2022 by | Leave a comment

Journal of Food Protection

Inshell walnuts could be contaminated with pathogens through direct contact or cross-contamination during harvesting and postharvest hulling, drying, or storage. This study aimed to assess the efficacy of ultraviolet–C (UV–C) radiation in inactivating foodborne pathogens on inshell walnut surfaces. Intact inshell walnut surfaces were inoculated separately with Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes , and Staphylococcus aureus , and then subjected to UV–C radiation at doses of 29.4, 147.0, 294.0, 588.0, and 882.0 mJ/cm 2 . UV–C radiation inactivated the inoculated pathogens in a dose-dependent manner, and a tailing effect was observed for the inactivation of pathogens. UV–C radiation at 29.4 mJ/cm 2 and 882.0 mJ/cm 2 reduced the populations of  S . Enteritidis PT 30, S . Typhimurium, E. coli O157:H7, L. monocytogenes , and S. aureus on inshell walnut surfaces by 0.82–1.25 and 1.76–2.41 log CFU/walnut, respectively. Scanning electron photomicrographs showed pathogenic bacterial cells in the cracks and crevices of the inshell walnut surface, and the shielding of microorganisms by the cracks and crevices may have contributed to the tailing effect observed during UV–C inactivation. No significant changes ( p  > 0.05) were found in walnut lipid oxidation following UV–C radiation at doses up to 882.0 mJ/cm 2 . Together, the results indicate that UV–C radiation could be a potential technology for reducing the populations of various foodborne pathogens on inshell walnut surfaces while maintaining the quality of walnuts.

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Posted in Decontamination Microbial, E.coli O157, E.coli O157:H7, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Technology, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Pathogen, pathogenic, Research, Salmonella, Staphylococcus aureus, Technology, UV Microbiology, UV-C

Research – Dutch survey finds a quarter of people wash chicken, despite expert advice

Posted on May 14, 2022 by | Leave a comment

Food Safety News

A survey in the Netherlands has found more than a quarter of people wash raw chicken, which public health officials say increases the chances of spreading bacteria.

Results come from two surveys by the Netherlands Nutrition Centre (Voedingscentrum) with the Dutch population about safe food handling.

The first survey in May 2021 with 2,000 participants asked Dutch consumers about general food safety handling in the domestic kitchen. One of the questions was if they washed their chicken.

A second survey in November 2021 with 1,000 respondents was focused on safe handling of chicken. People were asked if they washed their chicken and more details about why and how. Both surveys revealed that more than 25 percent of consumers washed their chicken often or almost always.

Bacteria on chicken can cause food poisoning. Usually it is because of Campylobacter or Salmonella.

Washing raw poultry is not recommended, because of concerns about contaminating other foods and surfaces and increasing the risk of foodborne illness.

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Posted in Campylobacter, campylobacter coli, Campylobacter jejuni, Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Retailer Campylobacter Survey, Salmonella, Salmonella in Chicken

Research – Attachment and survival of Salmonella enterica and Listeria monocytogenes on tomatoes (Solanum lycopersicum) as affected by relative humidity, temperature and time of storage 

Posted on May 14, 2022 by | Leave a comment

Journal of Food Protection

Tomatoes (Solanum lycopersicum) are one of the most consumed fruits worldwide. The fruit can become contaminated with Salmonella and Listeria monocytogenes at different stages of the production and supply chain, and these pathogens may survive under different storage conditions. The effect of relative humidity, temperature and time of storage on the attachment and survival characteristics of both pathogens on the surface of tomatoes was investigated. Fresh whole Roma tomatoes were inoculated with a cocktail of Salmonella or L. monocytogenes and stored at 5, 12, 25, 30, or 35 ºC for 10 days. Every day during storage, relative humidity and temperature were measured and tomatoes were removed to enumerate cells of these pathogens that were loosely attached (LA, cells detached from the tomato surface by simple rinse) and strongly attached (SA, cells that required sonication to detach. Enumeration was achieved by spread-plate method. Surviving populations of LA and SA cells were obtained and the attachment strength (SR) was calculated to express the proportion of SA cells on the tomato surface. The LA initial counts of Salmonella and L. monocytogenes on the surface of the fruit after inoculation were 6.6 and 6.5 log CFU/tomato, and for SA were 5.1 and 5.6 log CFU/tomato, respectively. For both pathogens, the LA counts were higher (p < 0.05) than the SA counts. Also, the LA and SA counts varied significantly as a function of temperature, relative humidity and time of storage. The S R for Salmonella was affected by the time but not the temperature of storage, while the S R for L. monocytogenes was affected by the temperature, relative humidity and time of storage (p < 0.05). Understanding the attachment and survival of Salmonella and L. monocytogenes on tomatoes stored at different temperature conditions may be useful in determining ways to prevent/reduce the establishment of pathogens and designing improved decontamination methods for tomatoes.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Technology