The device Violetta, which uses UV radiation for cleaning, was ordered by Stockmann and built by engineering researchers from Tallinn University of Technology. The device clears a client's reusable food box of bacteria, ensuring safe and operative cleanliness in eight seconds. UV light stops bacteria from multiplying and ensures the sterility of the box. This method is typically used to sterilize medical devices.

TalTech's engineering researcher Toivo Tähemaa, the creator of the device, affirmed: "Disposable food boxes have been a big problem for a green mindset. Product developers have always enjoyed problems, and solving them is an exciting challenge! The use of similar devices is common in medicine but using Violetta in retail is new. Violetta brings medical cleanliness to food takeaway."

Violetta began as a proposal by Stockmann's clients to package food into their own boxes to help the environment, decrease the use of disposable packaging, and enjoy delicious, high-quality, and healthy food.

Stockmann's sales director Mairika Juhandi said that the way of using the device is unique: "Food boxes are not known to be cleaned this way anywhere in the world. TalTech's scientists considered Stockmann's wishes for the size of the boxes and the effectiveness of the device while creating Violetta. The safety and convenience of the device for customer service workers were also taken into account."

Martinš Sarkans, a senior researcher of TalTech's Department of Mechanical and Industrial Engineering, added: "Violetta's control electronics have been chosen in a way that guarantees ease of use. For example, the duration of the cleaning process can be easily reprogrammed if needed."

Retail specialists from Stockmann and TalTech's mechanical engineers and food scientists worked closely together to develop the device – this way, they found the optimal cleaning strength and the time during which the bacteria in the box is destroyed.

Inga Sarand, associate professor of TalTech's Division of Food Technology, did experiments to check the effectiveness of the device. She explained: "We planted a growth culture and bacteria in food boxes and then processed half of them in the UV cleaning device. After a 24-hour incubation, no bacteria were found in the boxes cleaned in Violetta."

The solution, which was developed based on feedback from Stockmann clients in a unique collaboration with TalTech and is one-of-a-kind in Estonia, is important in decreasing the use of disposable packaging, promoting recycling, and a sustainable lifestyle.

Tallinn University of Technology (TalTech) is the flagship in engineering and IT science and education in Estonia, providing higher education at all levels in engineering and technology, information technology, economics, science, and maritime. The uniqueness of Estonia's only technical university lies in the synergy of fields that helps to birth new ideas.

Stockmann AS is a part of the Finnish retail group Stockmann Group. The fashion chain Lindex and real estate division Stockmann Real Estate also belong alongside the retail branch Stockmann Retail. Stockmann was founded in 1861 in Finland and came to Estonia for the first time in 1993. The department store in Tallinn in Liivalaia street was opened in April of 1996, and a wide selection of high-quality brands of fashion, beauty, and home goods and groceries have been represented there since.