Due to changes in increased public awareness about environment and health, strict packaging regulations and guidelines, a lot of effort has been put into development of innovative food packaging materials to achieve resistance against pathogens, to reduce unnecessary waste and spoilage, to reduce the use of chemical preservatives and to improve the nutritional and sensorial properties of food. Unfortunately, not many solutions proved to be adequate in terms of costs, environment and health.
Polypropylene and polyethylene commonly used for foils and films show permeability for gases like oxygen, little to no measurable antimicrobial activity and antioxidant activity at around 2 to 4%. As a consequence, these materials are treated with different solutions to enable desired characteristics like antioxidant and antimicrobial activity.
Researchers from a Slovenian institute and university with extensive experience in the field of food science and surface engineering have developed a method and initial design of corresponding apparatus for production of antioxidant and antimicrobial material.
The procedure starts with a substrate, usually made of polymeric materials like polyethylene (PE) or polypropylene (PP). PE or PP foil is treated to saturate the surface with polar functional groups, without changing its other properties. Wettability of the layer is improved at the same time, and that helps with the next step, where the chitosan layer is applied. The role of this layer is to provide a barrier for oxygen diffusion and antibacterial activity. Additionally, it helps the following layer, called active layer, to be adhered firmly and effectively on the previous one.
The third and final layer in general consists of antioxidant material (e.g. pomegranate extract) and chitosan nanoparticles that form a network. The chitosan in the active layer is intentionally used in form of nanoparticles due to particularly enhanced antibacterial properties when in this form. Along with the chitosan layers, the active layer also acts as additional oxygen permeation barrier.
Along with the method, adequate apparatus for producing packaging material was designed and it has several treatment units through which the material passes.
The research institute and university are looking for companies and other industrial partners for a license agreement to use this technology. Partners should specialize in production of flexible plastic food packaging materials with emphasis on foils and films. The research institute and university will provide the necessary information and other specifications, required for efficient and proper implementation of the method and apparatus in a production process, while partner will be able to use this technology in their production processes.