Use of infrared and UV investigated to inactivate microorganisms on meat

The inactivation of microorganisms by infrared and ultraviolet radiation will be investigated to find optimal process parameters which enable microbial reduction without significant changes to the product and material properties.

Surface sterilization of packaged meat and sausage products by IR or UV radiation should increase the microbiological safety and shelf-life as subsequent microbial contamination through the packaging can be ruled out.

There are no suitable approaches for post packaging disinfection of sensitive meat and meat products with the exception of antimicrobial active packaging.

Meat susceptibility ​

Meat and sausage products are susceptible to spoiling by microbiological organisms, said Fraunhofer.

A short shelf-life means more than 24% of meat products made in Europe are lost at some stage along the value creation chain, according to Gustavsson et al​, with the majority occurring in shops and after purchase by consumers.

The AiF (German Federation of Industrial Research Associations) funded project involves the German Institute for Food Technology (DIL) and began in October.

It is managed by the Industry Association for Food Technology and Packaging (IVLV) and runs until October 2018.

The goal is the design of a continuously running disinfection plant based on UV- or Infrared irradiation as well as demonstration of its suitability to disinfect the surface of packed meat and meat products without causing adverse effects on food quality.

Industrial partners from along the supply chain of meat products (producers, packaging manufacturers, machine builders) are involved to ensure practical relevance of the research.

IR or UV acceptance​

The work will involve construction of pilot plants based on infrared and UV sources (pulsed light, low pressure UV lamps) for a continuous treatment of packaged meat products to allow a high throughput in a short time and selection of packaging material with suitable transmission properties.

Infrared radiation to food is approved in the EU and treatment with pulsed light and UV radiation is backed in the US by the FDA.

Non-ionizing radiation is approved in Europe but not Germany, where the treatment of food (with some exceptions) is forbidden according to the German Food and Feed Code.

“Generally, food irradiation is refused by the publicity and especially the consumer. Compared to ionizing radiation (gamma or electron beam), UV radiation exhibits a much lower penetration depth, wherefore it is solely suitable for surface treatments,” ​said Fraunhofer.

Unlike various chemical preservatives, there are no issues regarding potential residues.

“Nevertheless, the impact of the IR and UV on the product needs to be assessed and the retentions of quality as well as safety have to be ensured. ​

“For example, the treatment of milk with UV light was confirmed to be safe according to EFSA under the intended conditions of use as specified by the applicant.”​

UV sources are commonly used for water and air disinfection and a range of products are commercially available and it is a similar situation for IR-heating equipment.

The consortium will do challenge tests to determine the best settings for inactivation of microorganisms on the surface of selected meat products.

Impact of the treatment on the product quality (e.g. colour, fat/protein oxidation), shelf life and material properties (e.g. migration measurement) and industrial field tests to assess industrial feasibility will also be performed.

The pilot plant throughput is planned to be around 50-100 kg/h and exposure time will vary according to the respective technology.

For pulsed light, only a few seconds will be necessary while a longer treatment time of around 5-30 seconds is expected for UV-C as well as infrared heating.