We will conduct five technical studies that will result in new solutions to the challenges in the food industry.
- We will develop a system that can produce at least 2 liters of plasma-activated water per minute, and test the water on vegetables, potatoes, fruit, eggs and chicken to document quality and durability.
- We will add the pathogen Listeria monocytogenes to packaged meat and investigate whether UV light exposure will inactivate the bacteria.
- We will treat vegetables and dairy products with microwaves combined with pressure, and compare them with traditional heat treatment in an autoclave.
- Supercritical CO2 under high pressure will be used on eggs and dairy products to find the effects on allergens.
- We will calculate the costs saved when drying foods subjected to pulsed electric fields and ultrasound, and document the quality.
Novel technologies are central to the project. We have selected six innovative processing technologies (IPTs) to process food in a more sustainable way, which will result in healthier and safer foods.
Inactivating bacteria using cold plasma is still at the development stage in the laboratory. Plasma is a gas ionized with electricity. The charged particles in plasma can destroy the cell membranes and DNA in bacteria so that the shelf-life of berries and vegetables is increased by up to five days. By rinsing fresh foods in water with cold plasma their shelf-life can be prolonged by one to two weeks. We expect to gain enough knowledge for the method to be used in the food industry.
Another method of inactivating bacteria on the surface of foods is UV light (UV-C). This has already been applied to bread products, but for packaged food, the technology is still being developed in the laboratory. We expect to increase the shelf-life of fresh foods with 5-6 days for packaged food.
Ultrasound is commonly used for cleaning laboratory equipment, and has also been tested on industrially produces foods, providing an increased shelf-life of 9 to 16 days. Ultrasound is an IPT that is particularly suitable in combination with heat treatment, because of rapid heat intrusion.
Pulsed Electric Fields
Pulsed Electric Fields (PEF) enables gentle cell opening of plant cells in fruits and vegetables and of microbial cells. In this project, the destruction of microbial cells will be investigated for milk, chicken, fruits and vegetables as well as the food quality. For potatoes, a PEF pre-treatment is expected to result in improved cutting, faster frying time and higher capacity. It also comes with savings in energy and water consumption. In liquids such as juices or milk, the PEF technique inactivates bacteria at lower temperatures than traditional pasteurisation which improves quality. The PEF technology is established in the food industry from about 2012 and there is a need for development of new applications and optimization of the existing products.
Using microwaves is a well-known method for rapid heating of food in the thousands of homes, but not so much used in the food industry. It is still expensive to produce microwave tunnels that provide stable temperatures in the food without it getting too hot in some parts and too cold in other parts of the food. Work is still underway to solve this, since the use of microwaves can save a lot of time and energy compared with other methods of heating food.
High pressure processing
A highly innovative method, well-known method in the food industry is high pressure processing (HPP). For instance, juice retains the same quality as if it was newly pressed for four to six weeks after being exposed to high pressure. It is common to use up to 6000 Bar. Not only are pathogen bacteria destroyed, but allergens can also be removed, and the documentation is important. Because of the extreme forces induced by such high pressur,e the pressure vessel and piping have to be very robust and, thus, expensive. To measure e.g. temperature inside the products during processing without compromising packaging integrity, is also very complicated.
In iNOBox we will document the effects of these technologies on selected foods and processes in the food industry.