How can we improve the sustainability of products on supermarket shelves while maintaining food quality? Wageningen Food & Biobased Research helps the industry to answer this question by developing and applying mild preservation techniques such as high pressure processing.
High pressure processing is one of the techniques that have already found their way onto the market. This is an alternative method for preserving products that are traditionally pasteurised or sterilised, such as cold meats, fruit juices & drinks, and ready-made meals. The new technique inactivates micro-organisms by exposing them to a pressure of up to a thousand MPa. Under these high pressures macromolecules are altered. Small molecules associated with flavours, colours and vitamins are not influenced. Therefore many food products can be treated without loss of fresh characteristics.
Wageningen Food & Biobased Research has more than 15 years of experience in high pressure processing, including microbiology, product research, process impact, technology development and consumer acceptance. Our main applications are:
- High pressure pasteurisation: reducing the number of (vegetative) micro-organisms and inactivate enzymes involved in product spoilage whilst retaining the fresh characteristics.
- High pressure sterilisation: inactivation of enzymes and micro-organisms including spores, resulting in an ambient stable product.
- High pressure product modification: creates new opportunities for product modification such as starch gelatinisation, denaturation of proteins to prepare gels, preparation of pectin gels (jams, texture modification of vegetables) and tenderisation of meat and fish.
High pressure sterilisation
When high pressures are combined with high temperature, it is possible to inactivate spores in food products and therefore sterilisation of products is achieved. This process is done at temperatures in the same range as conventional retort processing. The high pressures are used for rapid temperature increase and decrease, resulting in a high pressure processing time of 3-5 minutes. The total temperature impact on the product is therefore much smaller compared to conventional retort sterilisation resulting in a better product quality. Wageningen Food & Biobased Research proved that spores can be inactivated, product quality is improved and built pilot equipment up to 80 litres/h.
For both high pressure pasteurisation and sterilisation it is important to evaluate the microbial safety of the product after treatment. Not only spoilage micro-organisms are important, but also the inactivation of pathogens that could potentially be present in the process. Wageningen Food & Biobased Research has the facilities to evaluate the effect of high pressure at different P, T and t conditions on inactivation of vegetative cells and spores, including pathogens. For high pressure sterilisation we performed in depth research on the inactivation kinetics of spores under high pressure-high temperature conditions showing that this technology can be used for sterilisation of food products.
In Europe 37 partners worked together on the development of novel technologies, including high pressure treatments. Wageningen Food & Biobased Research coordinated this project that also included an Industrial Advisory Platform to stimulate the cooperation with industry and to disseminate the project results to potential users of the technologies. In NovelQ research was done on mechanisms of high pressure conditions on microorganisms, texture, enzymes and food components. In addition packaging material was developed that can be used for high pressure sterilisation treatments. Results are described in the final report of the project and over 150 scientific publications.