127 | Listeria Risks: New Insights | Food Safety Snapshot | Reusing Plastic Food Packaging |

Plus: What's wrong with this picture?

• Listeria risks and controls: new insights;

• Packaging corner: PFAS testing and plastic reuse risks;

• Food safety snapshot: labelling errors and chemical contamination;

• Food Safety News and Resources;

• What’s wrong with this picture? (just for fun)

• Food fraud news, emerging issues and recent incidents

🎧 Listen (now for everyone!) 🎧

Hi,

Welcome to Issue 127, thank you for joining me. And a special huge thank you to new subscribers 👏👏 Anna and Clare 👏👏 for supporting my work and our food safety community.

In this week’s issue, I share nuggets of wisdom from a WTO symposium on illicit food trade, so you don’t have to view the 14-hour 😮 replay yourself (you’re welcome!). Find those insights in the food fraud news section at the bottom of this post.

Also this week, food testing results from the United Kingdom (mycotoxin nutmeg, anyone?), February’s packaging corner and new science-supported insights on Listeria risk-based controls. Plus our first ever competition: win stickers (and bragging rights).

Karen

P.S. If you’re a paying subscriber, don’t forget you can get access to subscriber-only content on the website. There’s a special section for paying subscribers, with extra supplements, downloadable compilations, recorded training sessions and more.

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Listeria Risks and Controls: New Insights

In food safety, risk assessments are performed for foodborne pathogens so that controls and mitigations can be targeted and effective. In the case of Listeria, risk assessments aim to prevent contamination and growth of the bacterium in food production environments and food products.

Reminder: We care about Listeria because it has a very high hospitalisation rate (94%) and a very high mortality rate (20 - 30%) compared to most foodborne pathogens. And it can multiply in food while it is in the refrigerator.

Many qualitative and quantitative risk assessments have been published for Listeria over the years. The most common food addressed in these risk assessments is meat products because meat is a common vector for listeriosis infections.

Sliced ready-to-eat meat is high-risk for Listeria. Image: what Open AI’s bot thinks a delicatessen meat-slicing machine looks like. Made with DALL-E

What if we could look at all the risk assessments together and figure out which controls are best overall when it comes to reducing the risk of foodborne illness from Listeria?

We can! Researchers have examined 23 quantitative risk assessment models for Listeria monocytogenes in meat products to understand the relative effectiveness of controls and extract key information for future Listeria risk assessment models.

Processed meat products become contaminated with L. monocytogenes in two main ways: either (1) the raw materials are initially contaminated and processing methods fail to sufficiently reduce the pathogen's presence, or (2) contact between the finished product and contaminated raw materials or other surfaces results in post-processing contamination.

Cross-contamination can occur during processing by the manufacturer, for example during slicing, or while the product is in the care of the retailer, for example, during deli handling or slicing, or in a consumer’s home.

The risk assessments considered a range of controls including refrigerator storage temperatures, duration of storage, product formulation (acid, fermentation cultures, water activities), growth-inhibitors (nitrites, lactate, diacetate), biopreservatives (lactic acid bacteria cultures), post-process lethality treatments (in-package pasteurisation, irradiation, high-pressure processing) and vacuum-packaging.

After reviewing the risk assessments, researchers concluded that, when viewed as a whole, they converged on two key outcomes:

1. When it comes to food storage conditions and shelf life, shortening the time to consumption (shorter expiry date) was less effective at reducing risk than ensuring that cold storage temperatures were properly controlled.

2. While it is important to have properly controlled storage temperatures and short storage duration in retail outlets and homes, it is far more effective to have lower numbers of L. monocytogenes at the end of processing, including after slicing in a retail setting.

While these outcomes are perhaps not surprising to food safety experts, it is good to hear that these Listeria prevention strategies are robustly supported by the latest science.

In short: 🍏 Risk assessments are performed for foodborne pathogens so that controls and mitigations can be targeted and effective 🍏 Researchers who reviewed 23 quantitative risk assessments for Listeria monocytogenes in meat products concluded that properly controlled refrigerator temperatures led to a greater quantifiable risk reduction than shorter storage durations, and that lower levels of contamination at the end of processing were far more effective than controlling storage temperature or duration 🍏

Source:

Gonzales-Barron, U., Cadavez, V., De Oliveira Mota, J., Guillier, L. and Sanaa, M. (2024). A Critical Review of Risk Assessment Models for Listeria monocytogenes in Meat and Meat Products. Foods, [online] 13(3), p.359. doi: https://doi.org/10.3390/foods13030359.

‌Learn more:

Get the Facts about Listeria | FDA

BRCGS Ask the Experts (ep 8): Listeria Management (webinar)

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Packaging Corner

Food safety and quality challenges from reusing plastic packaging

The reuse of plastic packaging is different to the recycling of plastic packaging. Reuse means the regeneration of packaging that has already been used, through washing and sanitising the containers. Industrial reuse processes are usually performed by washing at 55–65 °C and rinsing at 70–85 °C with caustic detergents. Higher temperatures are better for microbial decontamination but plastics have an upper temperature limit for hot washing, depending on the material.

Single-use and reuse models for plastic packaging: main steps involved and related issues. Source: Licciardello (2024)

With sustainability experts calling on wider reuse of plastic packaging, a new paper explores the risks arising from the reuse of plastic food packaging, including the hygiene and sensory aspects, as well as risks arising from the migration of chemical additives into foods and the generation of microplastics through reuse.

The paper (open access):

Licciardello, F. (2024). Unexpected possible consequences of plastic packaging reuse. Current Opinion in Food Science, [online] 56, p.101131. doi: https://doi.org/10.1016/j.cofs.2024.101131.

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New PFAS detection method

Researchers claim to have developed a fast and sensitive detection method for PFAS in food packaging, water and “social samples”.  The method uses paper spray mass spectrometry (PS-MS) and has a claimed detection limit of 1 part per trillion (ppt).

Learn more: Method developed to detect PFAS (newfoodmagazine.com)

🍏 More on this topic: PFAS in Food and Packaging – An Emerging Food Safety Issue (Issue 73) 🍏

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Food Safety Snapshot: Labelling Errors and Chemical Contaminants (UK)

In October 2022, the Food Standards Agency (FSA) of the United Kingdom sampled 28 different commodities from national supermarkets, independent retailers and online sellers in England, Wales and Northern Ireland.  A total of 1,215 samples were tested for contamination, undeclared allergens, authenticity and labelling errors.

Nineteen percent of samples (n = 1,215) were unsatisfactory, with packaged breads being the worst-performing product type.  Smaller outlets performed worse than national supermarkets.

Sixteen percent of samples tested for allergens (n = ?) contained undeclared allergens. Yup, that’s more than one in seven foods which are potentially deadly to allergic consumers!

For undeclared allergens, spices and ‘prepacked foods for direct sale’ were the worst food types, with almost one-third of African spices containing undeclared peanut proteins. More than one-third of prepacked foods for direct sale contained allergens that were not correctly declared on the pack.

Other notable food safety results were around the presence of mycotoxins. Nine percent of nutmeg, turmeric and oregano samples (n = 89) contained mycotoxins at levels above regulatory limits, with ground nutmeg the most common offender.  One sample of dried oregano had high levels of lead.

Authenticity-related non-compliances were discovered in meat products, oregano, olive oil, basmati rice and sliced turkey. These are described in this week’s food fraud news.

FSA survey assesses food product compliance | Food Safety News

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Food Safety News and Resources

Our food safety news and resources roundups are always free and never boring.

This week’s most unusual outbreak: Infants affected by Bacillus cereus toxin in packaged porridge/oatmeal products

Click the preview box below to access it.

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Photo Competition (Just for Fun)

Keeping with the Listeria and sliced meat theme from this week’s main story, I found this picture online, but couldn’t use it in the main story because of the food safety non-conformities it depicts.

For a chance to win The Rotten Apple stickers, reply to this email with a list of all the non-conformities in the picture (assuming this photograph was taken in a supermarket/grocery store deli), and include a humorous caption too if you wish (optional).

Image: Freepik

Prizes will be awarded for:

• the most non-conformities spotted, and

• the most creative caption.

Winners announced next week.

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Below for paying subscribers: Food fraud news and incident reports

📌 Food Fraud News 📌

In this week’s food fraud news:

📌 Oregano (and other foods) fraud in the UK;

📌 Update from the Codex working group on food fraud;

📌Future trends in food fraud (Prof John Spink via a WTO symposium);

📌“Massive” fraud alleged in mineral water;

📌Guidance: DNA extraction methods;

📌Food crime guidance for small businesses;

📌 Fraud in butter, steroids in catfish, condiments made from waste, oil made with offal and more.

Fraud discovered in FSA survey (United Kingdom)

Authenticity tests were included in a survey which tested 1,215 samples of food in the United Kingdom (UK) in 2022. Oregano, olive oil and other foods had test results that indicated probable fraud. For dried oregano, the percentage of non-compliant samples was