EUROPE – The European Food Safety Authority (EFSA) has in a scientific opinion concluded that high-pressure processing (HPP) of food is effective at destroying harmful microorganisms and poses no more food safety concerns than other treatments.

EFSA experts assessed the safety and efficacy of HPP of food and, more specifically, whether it can be used to control Listeria monocytogenes in ready-to-eat (RTE) foods and as an alternative to thermal pasteurization of raw milk.

HPP is a non-thermal food preservation technique that kills microorganisms that can cause diseases or spoil food. It uses intense pressure (300–600MPa) for a certain time and has minimal effects on taste, texture, appearance, or nutritional values.

The pressure is transmitted through water, which completely surrounds the packaged food. As the pressure is equally distributed, there is no obvious crushing effect.

HPP is suitable for foods that have a high-water content and can be used at different steps of the food chain, usually on pre-packed products.

It is particularly useful for raw foods, when retention of fresh characteristics is important, such as milk, fruit juices, and smoothies but also to products that have already been processed, such as sliced cooked meat products and RTE meals.

In the latter case, it reduces the contamination originating from the manufacturing environment, for example during slicing and manipulation of the products.

This processing method reduces levels of Listeria monocytogenes in RTE meat products, at specific time-pressure combinations defined in the scientific opinion.

In general, the longer the duration and intensity of the pressure, the more reduction is achieved. This is an important finding since L. monocytogenes contamination of RTE foods is a public health concern in the EU.

The food industry commonly applies pressures of between 400 and 600 megapascals (MPa) for microbial inactivation, with common holding times ranging from 1.5 minutes to 6 minutes.

HPP also proved to be effective at reducing the levels of other pathogens, such as Salmonella and E. coli.

Experts identified the time-pressure combinations that can be considered to have the same effect as thermal pasteurization for raw milk. However, these vary depending on the pathogen considered.

HPP is not specifically regulated at EU level and EFSA’s advice will inform the possible decisions of risk managers in this field.

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