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Published: 7 Jun 2022

World Food Safety Day (7 June 2022) is designed to draw attention and mobilise action to prevent, detect and manage foodborne risks and improve human health.

The Tasmanian Institute of Agriculture’s Food Safety & Innovation Centre provides industry and government with access to cutting-edge research and knowledge of emerging issues related to food safety and shelf life, while supporting the food industry to achieve improved safety and shelf-life of food.

Our researchers are internationally recognised for leadership in modelling the ecology of bacteria in foods, a discipline called ‘predictive microbiology’.

Lyndal Mellefont, lecturer in microbiology, is part of that team. Lyndal started as a University of Tasmania undergraduate, and one of her first jobs was working for the Food Safety & Innovation Centre’s Preparation Room team washing up glassware.

What are some common foodborne risks we are/can be potentially exposed to?

As food microbiologists in TIA, we focus on microorganisms in foods that are either used to produce the food or food ingredients, spoil the food or cause safety issues.

Foodborne risks are not just biological. There are chemical and physical foodborne risks too. You often see food recalls associated with allergens in foods, contamination with plastics or even direct tampering (e.g., 2018 needles in strawberries sabotage in Australia).

In today’s busy society and the ease with which we travel, significant risks arise from eating food that you have not prepared yourself, or that you might consider come from an unsafe source.

Ready-to-eat foods (RTE) that do not require further cooking, such as processed meats, or RTE meals that are mass produced also carry risks of contamination with pathogens from raw ingredients or during food processing.

Food that is undercooked or not held at a sufficiently high temperature - the so-called DANGER ZONE of 4 to 60 °C - can allow the growth of many harmful microorganisms.

Or, as in the case of foods prepared or cleaned with contaminated water, it’s common to be told when travelling to not eat the leafy garnishes or have ice in your drinks if you are in an area of questionable water quality. This is a common way people contract ‘Travellers Diahorrea’ or ‘Bali Belly’.

How is research in this space evolving to meet foodborne risks?

Foodborne risks are studied throughout the whole farm-to-fork, fish-to-dish, moo-to-munch continuum.

Characterising microbial profiles of foods, how naturally present and introduced microflora interact, and the fate of microorganisms throughout food processing and distribution provide insights as to how we can prevent their contamination of the food or, if it is inevitable that they are present, how we prevent their proliferation.

There is significant investment in new processing technologies such as cold plasma which uses ionised gas to inactivate bacteria, parasites and viruses without heating or damaging the food or food processing surfaces.

Research into novel antimicrobials, usually chemicals that can impede or kill microorganisms without changing the organoleptic properties of the food, can be focused on modification, or new combinations of known preservatives or exploring novel compounds such as plant essential oils, particularly herbs and spices.

New food packaging technologies have arisen such as active packaging (which involves incorporation of additives in sachets, films or coating, e.g. nisin which can inhibit some bacteria, packaging films with chitosan that acts as an antifungal) and intelligent packaging (the packaging monitors the condition of the food and provides information in real time, often with a colour indicator to tell you when the food becomes ‘unsafe’).

Can you please highlight some research you and the Food Safety & Innovation team are currently working on that aims to mitigate or reduce these risks?

Recently the CFSI group received funding for an international collaboration assessing the efficacy of a novel, natural antimicrobial for a range of RTE processed meats.

RTE cooked meat products are often associated with listeriosis as some formulations allow the growth of the pathogen Listeria monocytogenes, even if refrigerated, and/or post processing contamination can occur.

While L. monocytogenes can cause a mild illness in healthy people but can have high mortality rates in a susceptible group of people referred to as YOPIs (young, old, pregnant immunocompromised).

Why were you drawn to studying and working in food safety and innovation?

My food safety journey at the University of Tasmania started as an undergraduate and one of my first jobs was working for our Preparation Room team washing up glassware.

This then evolved to assisting researchers and securing a job in a UTAS run microbiology consultancy laboratory called Aquahealth.

In that National Association of Testing Authorities (NATA)-accredited testing laboratory I tested many export-grade food samples, ranging from tinned abalone, to hot and cold-smoked salmon and even fresh crayfish.

That strong foundation in food safety related laboratory skills led to my recruitment to pursue a research higher degree pathway funded by Meat and Livestock Australia.

In the process of obtaining my PhD it became evident that I was under the tutelage of a world-renowned food microbiology group.

It’s amazing to think that some of my work ‘underpins’ (that is a nod to group founder Professor Tom McMeekin, who often used that word!) Australian Government Export Control (Meat and Meat Products) Orders that assure the hygienic adequacy of meat processing in Australian export abattoirs.

What has been the most important scientific development in recent history to help reduce or mitigate foodborne risks to human health?

As I said earlier, there is a lot of new technology out there and there are also new approaches based on a much better scientific understanding of microbial ecology and physiology in foods (e.g., predictive microbiology). However, the utility or accessibility of tools and approaches is not yet universal due to infrastructure requirements and costs etc. Conversely, the wide availability of the internet has enabled much better dissemination of information and decision support tools to industry and the public.

Something that I think has been a double-edged sword as a scientific development is the ‘refrigerator’ (domestic and commercial).

Without a doubt this commonly available device, when run correctly at the recommended temperature of around 4-5 °C, has allowed us to increase the shelf-life and safety of foods and, in turn, reduce the incidence of foodborne disease in comparison to our forebears.

But, at the same time, it has also introduced us to a new range of pathogens which can happily grow at low temperatures (such as Listeria monocytogenes, Campylobacter spp., some types of Escherichia coli and others). But it is commonly reported that most of our domestic refrigerators run much higher than desired, around 7-8 °C, and this means other pathogens can start to grow, e.g., Bacillus cereus which is associated with ‘fried rice’ poisoning. It seems as fast we change our technologies different microorganisms will find a way to exploit them!

TIA is a joint venture of the University of Tasmania and the Tasmanian Government.