MICROBIAL RISK ASSESSMENT
The two RTOs, CNTA and Teagasc, focused on the inactivation of spore-forming spoilage organisms: G. stearothermophilus, B. amyloliquefaciens, C. sporogenes, B. coagulans, B. licheniformis B. cereus. Technical University of Munich (TUM) studied the behaviour of C. botulinum. A clear synergistic effect of high pressure and temperature was shown for spores. The time needed for a 5D reduction could be reduced from 3 to 20 times compared to thermal treatment alone, depending on the microorganisms. The come-up time is an important factor to be considered in spore inactivation.
The results of this part of the study have allowed the definition of combinations of pressure / Temperature / time (P/T/t) that allows to achieve the desired inactivation level for the 3 target types of products and storage conditions.
DEVELOPMENT AND SCALE-UP OF EQUIPMENTS AND TOOLS
In this WP the design, development and construction of a full-scale HPT processing system, including auxiliary units was carried out. The HPT vessel included a patented system that allow to maintain the desired temperature inside the vessel avoiding to heat it. An innovative basket and an automatic manipulation stainless steel basket system were also developed.
In parallel a temperature sensor was developed that can be used during the HPT process. The sensor is made of a pressure resistant casing and a traditional wireless temperature sensor with which the temperature can be logged. A mathematical model was developed to adjust for the measured temperature delay caused by the casing.
VALIDATION AND DEMONSTRATION
Tests with a simulation tool were performed by TOP checking a wide variety of food ingredients exposed to 4 different simulated sterilisation methods. Almost all results show that the quality of HPT processed food is indeed better than that of their retorted counterparts although is not equally beneficial for all food applications.
Tests were performed in 10 ready to eat meals by CNTA. The results obtained demonstrated that the more intense HPT treatment tested allow to achieve stability independent of storage temperature in all the tested products. In addition, the HPT treatment allow to obtain products with better sensorial quality compared to traditional thermal process. However, not all the products show the same benefit. Finally, tests using HIPSTER HPT system were carried out that allow to validate the working principles of the developed system.
A review of the legal requirements was performed by TEAGASC for the application of HPT in Europe. Also the role of the Food Business Operator in implementing the technology was researched. In addition, TOP BV performed a Critical Control Point study. From this study, 6 Critical Control Points were identified.
Regarding the sustainability of the HPT technology, ACTALIA has assessed and compared the potential environmental performance of the HPT technology with a thermal and a freezing treatment using the LCA methodology. When compared HPT processing with thermal pasteurization/sterilization in a retort, no apparent benefit for the HPT technology was found. In frozen supply chain context, the environmental burden is mainly shared between food production and cold storage. Replacing a freezing treatment by a HPT one would allow to store and ship meals at chill temperature and consequently, to reduce significantly energy consumption related to these activities.
DISSEMINATION AND EXPLOITATION
The main dissemination activities performed were: open access scientific publications (1), contributions to scientific events (6), workshops for food industries (2), videos (10), press release (15) and non-scientific publication (23).
These activities have allowed to bring closer the potential of this technology to the food industries, bringing opportunities for the industrial implementation. The dissemination activities of this scientific knowledge have increase the trust, of the stakeholders involved, in the HPT technology.
The exploitation activities have been:
- select the most impacting output of the project,
- propose the exploitation strategy for the results with potential for direct industrial or commercial application,
- manage the IPR policy. 2 patents have been developed within the project.
