Category Archives: Research

Microbial safety and quality of various types of cooked chilled foods

Posted on October 24, 2012 by | Leave a comment

Science Direct

Refrigerated Processed Foods of Extended Durability (REPFEDs) are a diverse group of food products. Their production process consists of a variable sequence of different processing steps leading to various types of REPFEDs being introduced to the market. To assure microbial safety, the food industry relies on a combination of mild heat treatment (i.e. pasteurization), appropriate product formulation (i.e. pH, water activity, modified atmosphere packaging, preservatives), cold storage and shelf life limitation. In this paper a classification of REPFED food types is presented and their microbiological safety is evaluated. REPFEDs were classified according (i) to the production process and (ii) to the expected consumer’s reheating practices. To evaluate the microbiological safety, historical data on the microbial contamination of REPFEDS were collected from five companies, 706 analyses on the day of production (T0) and 2912 analyses at the end of shelf life (TEoS). Results demonstrated that the microbial safety of the products is overall satisfactory. The number of samples exceeding the acceptable levels for Bacillus cereus/sulfite reducing Clostridia (T0: 103 CFU/g, TEoS: 105 CFU/g) was 4.07%/1.94% at T0 and 2.04%/0.69% at TEoS. None of the samples exceeded the acceptable levels for Listeria monocytogenes (T0: Absent in 25 g, TEoS: max 102 CFU/g). In addition the temperature of 38 products was monitored during reheating according to instructions of the manufacturer. The pasteurization values obtained during reheating are very heterogeneous, and only 7 products obtained a P70 of 2 min throughout the entire product. To assess the effect of reheating on L. monocytogenes a challenge test (including reheating) of paella with L. monocytogenes was performed. This demonstrated that L. monocytogenes can grow up to 0.63 log CFU/g in 6 days at 4 °C and that reheating the paella according to the instructions on the label does not guarantee absence of L. monocytogenes. These findings demonstrate the microbial food safety of the tested REPFEDs is satisfactory, and that producers should not rely on the reheating at consumer level to eliminate L. monocytogenes.

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Posted in Bacillus, Bacillus cereus, Bacteria, Clostridium botulinum, Clostridium difficile, Clostridium perfringens, Eurofins Laboratories, Food Hygiene, Food Safety, Food Testing, Listeria, Listeria monocytogenes, Microbiology, Pathogen, Research

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FDA Presentation on Food Safety for Moms (Mums) To Be.

Posted on October 22, 2012 by | Leave a comment

FDA 

 

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Posted in Bacteria, Food Poisoning, Food Safety, Microbiology, Research

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FSA – Bugs Like it Hot Poster

Posted on October 22, 2012 by | Leave a comment

FSA

May be useful as a poster at Work, Schools or Factory as it is always good to keep the educational posters refreshed.

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Posted in Bacteria, Food Safety, Research

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EFSA Fact Sheets –

Posted on October 22, 2012 by | Leave a comment

Antimicrobial Resistance

Campylobacter

Foodborne Zoonoses

Salmonella

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Posted in Bacteria, Campylobacter, EFSA, Eurofins Laboratories, Microbiology, Research, Salmonella

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Hospital Food – Clostridium difficile?

Posted on October 22, 2012 by | Leave a comment

WEBMD

A new report suggests that hospital food is frequently contaminated with the dangerous diarrhea bug Clostridium difficile (C. diff).

Houston researchers found that about one-fourth of nearly 100 hospital food samples they tested were positive for C. diff. Among the worst culprits: turkey, chicken, and egg products, vegetables and fruits, and desserts. Almost all were cooked.

It’s only one hospital. And no cases of human infection were linked to the food.

But together with past research, the findings suggest that contaminated food may be an important route of spread of C. diff in hospitals, says researcher Hoonmo Koo, MD, an infectious diseases specialist at Baylor College of Medicine in Houston, Texas.

Moreover, the temperatures at which hospital foods are cooked may be too low to kill the bug, he says.

An infectious diseases expert not involved with the research says the major C. diff strains that contaminate food are different from the ones responsible for human disease.

C. diff has been recovered from pigs, cows, and chickens, and the bug has been found in retail meat and salad greens. A few studies have found that the C. diff strains found in animals are the same ones causing human disease, but others have found the opposite.

A 2008 CDC study concluded that “although they share similar clinical features, evidence suggests that the predominant strains causing C. diff [disease] in humans and different animal species are distinct.”

Overall, though, surprisingly few studies have examined the possible link between C. diff disease in food, animals, and humans, according to both the CDC and Koo.

So the researchers tested about 2 tablespoons of each food item served over 80 days at a university hospital in Houston. The number that tested positive for C. diff:

  • Four of eight (50%) turkey samples
  • Four of 12 seafoods (33%)
  • Two of 17 beef servings (12%)
  • One of eight pork servings (13%)
  • Six of 14 chicken and egg products (43%)
  • Six of 27 vegetables and fruits (22%)
  • None of two grains
  • Three of five desserts (60%)

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Posted in Bacteria, Clostridium difficile, Food Safety, Food Testing, Microbiology, Pathogen, Research

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Risk reduction assessment of waterborne Salmonella and Vibrio by a chlorine contact disinfectant point-of-use device

Posted on October 21, 2012 by | Leave a comment

PubMed

Unsafe drinking water continues to burden developing countries despite improvements in clean water delivery and sanitation, in response to Millennium Development Goal 7. Salmonella serotype Typhi and Vibrio cholerae bacteria can contaminate drinking water, causing waterborne typhoid fever and cholera, respectively. Household water treatment (HWT) systems are widely promoted to consumers in developing countries but it is difficult to establish their benefits to the population for specific disease reduction. This research uses a laboratory assessment of halogenated chlorine beads treating contaminated water to inform a quantitative microbial risk assessment (QMRA) of S. Typhi and V. cholerae disease in a developing country community of 1000 people. Laboratory challenges using seeded well water resulted in log(10) reductions of 5.44 (±0.98 standard error (SE)) and 6.07 (±0.09 SE) for Salmonella serotype Typhimurium and V. cholerae, respectively. In well water with 10% sewage and seeded bacteria, the log(10) reductions were 6.06 (±0.62 SE) and 7.78 (±0.11 SE) for S. Typhimurium and V. cholerae, respectively. When one infected individual was contributing to the water contamination through fecal material leaking into the water source, the risk of disease associated with drinking untreated water was high according to a Monte Carlo analysis: a median of 0.20 (interquartile range [IQR] 0.017-0.54) for typhoid fever and a median of 0.11 (IQR 0.039-0.20) for cholera. If water was treated, risk greatly decreased, to a median of 4.1×10(-7) (IQR 1.6×10(-8) to 1.1×10(-5)) for typhoid fever and a median of 3.5×10(-9) (IQR 8.0×10(-10) to 1.3×10(-8)) for cholera. Insights on risk management policies and strategies for public health workers were gained using a simple QMRA scenario informed by laboratory assessment of HWT.

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Posted in Bacteria, Food Safety, Food Testing, Microbiology, Research, Salmonella, Vibrio, Vibrio cholera, Vibrio parahaemolyticus, Vibrio vulnificans, Virus, Water

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Inhibitory Effect of Carob on Listeria monocytogenes

Posted on October 18, 2012 by | Leave a comment

Journal of Agriculture and Food Chemistry

In recent years, there has been great development in the search for new natural compounds for food preservation aimed at a partial or total replacement of currently popular antimicrobial chemicals. Carob (Ceratonia siliqua) offers a natural promising alternative for food safety and bioconservation. In this work, the methanolic extract of carob leaves (MECL) was tested for the ability to inhibit the growth of a range of microorganisms. MECL inhibited the growth of Listeria monocytogenes at 28.12 μg/mL by the broth microdilution method. The effect of this bacteriostatic concentration on the growth of this bacterium revealed a pattern of inhibition characterized by (a) a resumed growth phase, which showed a lower rate of growth if compared with controls; and (b) first a lag and then a stationary phase at a lower bacterium concentration. The study of the chemical composition of MECL by high-performance liquid chromatography and liquid chromatography/mass spectrometry showed the presence of gallic acid, (−)-epigallocatechin-3-gallate, myricitrin, isoquercitin, catechin, chlorogenic acid, and malic acid. L. monocytogenes growth inhibition was recorded for myricitrin and gallic acid at 450 μg/mL and for (−)-epigallocatechin-3-gallate and isoquercitin, respectively, at 225 and 112.5 μg/mL. Taking into account that proline is a ligand of proline dehydrogenase (PDH), the use of this compound leads us to hypothesize the mode of action of MECL constituents.

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Posted in Bacteria, Eurofins Laboratories, Food Safety, Food Safety Alert, Food Testing, Microbiology, Pathogen, Research

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FSA – Food Handlers Fitness to Work Advice

Posted on October 18, 2012 by | Leave a comment

FSA

Food handlers who work while infected with certain bacteria or viruses can spread infection to other people through food they work with. This guidance helps managers and staff to prevent the spread of infection by advising which illnesses and symptoms staff should report and what managers should do in response.

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Posted in Bacteria, Food Hygiene, Food Illness, Food Poisoning, Food Safety, Food Testing, Illness, Microbiology, Pathogen, Research

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HPA – eBugs Website- New site for Learning About Microbiology

Posted on October 16, 2012 by | Leave a comment

eBugs : For all Microbiology not just Food

 

 

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Posted in Bacteria, HPA, Microbiology, Research

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Controlling Microbiology of Meat with Active Packaging Research

Posted on October 2, 2012 by | Leave a comment

Science Direct

Abstract

Antimicrobial packaging appears to be a promising application of active food packaging technology. This project was undertaken to evaluate the effectiveness of selected antimicrobial packaging structures in improving the microbial quality of a ready-to-eat (RTE) meat product. Cooked ham samples (25 g) inoculated with a five-strain mixture of Listeria monocytogenes (2 or 4 log CFU g−1) were packaged into three different antimicrobial packaging structures, respectively, and samples in the non-antimicrobial packaging structure served as controls. The samples were stored at 4, 10, or 22 °C, and populations of total aerobic bacteria, Enterobacteriaceae, and inoculated L. monocytogenes were determined twice a week over a 4 w storage period. Packaging structures with an O2 scavenger or a CO2 generator were more effective than the structure with an allyl isothiocyanate (AIT) generator. Listeria populations in the packaging structure with the O2 scavenger were 1.80–2.65, 3.69–4.76, and 4.62–4.67 log CFU g−1 lower than the controls at 4, 10, or 22 °C. Samples in the packaging structure with the CO2 generator were 1.11–1.63, 4.30–4.45, and 4.01–4.44 log CFU g−1 lower than the controls at 4, 10, or 22 °C. Significant inhibitions on total aerobic bacteria and Enterobacteriaceae counts were also observed in packaging structures with the CO2 generator and O2 scavenger. However, packaging structures with the AIT generator only significantly inhibited L. monocytogenes, total aerobic bacteria, and Enterobacteriaceae in some samples, mainly those stored at 22 °C. These results suggest that some of the evaluated packaging structures can effectively control bacterial populations, particularly Listeria populations on RTE meat products.

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Posted in Bacteria, Enterobacteriaceae, Food Hygiene, Food Testing, Listeria, Listeria monocytogenes, Microbiology, Pathogen, Research

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