Tomatoes are one of the most widely consumed vegetables, being the second most important vegetable crop worldwide – with a total production in 2013 of 14.9 million tonnes in Europe. They are of particular importance because of health promoting compounds including vitamins A, C, E, lycopene, β-carotene and other bioactive nutrients. Due to their high moisture content, tomatoes deteriorate rapidly after they are picked up. During the fresh-cut elaboration process, a series of operations like mechanical cutting, washing and disinfection, are carried out, and as a result of this, a large number of physiological phenomena may occur – such as biochemical changes and microbiological spoilage – which may result in degradation of colour, texture, and flavour. Dehydration is one of the methods used in the food industry to prevent such conditions and extend the shelf life of tomatoes. Drying removes the water that bacteria, yeasts and molds need to grow, while retaining the organoleptic and nutritional properties of tomatoes. The drying process is commonly used in combination with other techniques such as washing with chlorine – for the removal or inactivation of pathogens – and packing in oil – as preservation method. However, these techniques have a few disadvantages. Chlorine has a limited effect in killing bacteria and is associated with the formation of by-products, such as trihalomethanes, which are potential carcinogens. On the other hand, preserving in oil imply extra costs. These products are heavier – due to the addition of oil – therefore more expensive to transport and handle.
In order to address these issues, our project SHOCKO3 aims at introducing ozone in the processing line and eliminating the use of oil to preserve food. Research and recent commercial applications have verified that ozone can replace traditional sanitizing agents, like chlorine, and provide other benefits. Ozone is considered one of the most powerful oxidizing agents used to increase safety of fruits and vegetables, and to increase shelf life. Furthermore, ozone is a safe and environment-friendly technique, more effective than chlorine, without formation of harmful by-products.
