New IFR study helps to identify food poisoning in raw foods
Published:  15 January, 2016

A report from the Institute of Food Research (IFR) has given new evidence on the background levels of spores of clostridium botulinum (C.botulinum) – a form of food poisoning – in raw foods, that it claimed will assist the food industry in delivering safe chilled foods more sustainably. 

The strain of food poisoning is so severe that even the slightest consumption of contaminated food can lead to extreme illness and potentially even death. As a result of this, the industry uses high-quality raw materials, hygienic manufacturing practices and strict levels of safety criteria when producing food to prevent potential spread. Outbreaks have occurred when these guidelines have not been adhered to in the correct fashion.

Despite this, consumer demands for reduced preservatives, milder heat processing and an extended shelf-life are leading to the industry constantly coming up with new and innovative products, particularly in the minimally processed chilled foods sector. However, this could present some challenges in containing C.botulinum. According to the report, a complete understanding of how these adaptations within the industry could affect the germination and growth of food poisoning bacteria is needed.

Under the Sustainable Shelf Life Extension (SUSSLE) project, IFR, the Chilled Food Association and Unilever Research worked together to develop the sustainability of minimally processed chilled foods. This is achieved by utilising quantitative risk assessment to set an appropriate shelf-life regarding C.botulinum.

The research explored how many spores of the strain of food poisoning there are in raw foods prior to them being processed. C.botulinum spores are present in several differing environments. However, they only become dangerous once they germinate and produce their deadly toxin in food.

Professor Mike Peck, from IFR’s Gut Health and Food Safety Programme, accompanied by his team, developed an optimised protocol which is thought to be a very sensitive enumeration method for detecting spores in food materials, with the ability to detect as little as 10-100 spores per kilogram. Despite this, the actual level of contamination with spores is usually lower than this, with just one spore being enough to germinate and cause illness.

“The evidence shows that, for many raw food materials, typical spore loads are smaller than previously reported,” explained Peck. “This makes a big difference on how we make decisions about food safety and risk assessment.”

The researchers combined information from hundreds of historical studies with experimental and statistical approaches in order to quantify typical spore loads for different food types.

The findings show how to improve active surveillance of foods by demonstrating what resources could best be used in this area. For instance, in regards to meat and fish, additional control experiments involving expected spore loads are considered most effective.