Functional Materials for Active and Intelligent Food Packaging Applications

Food products undergo numerous spoilage processes due to their highly perishable nature. Decreased food quality causes food borne diseases that affect the public health and well-being of the society. Therefore, manufacturers, retailers, consumers and regulatory agencies demand higher quality standards, and the adoption of strategies that enable the real time monitoring/traceability of the food quality throughout the supply chain. Recently the advances in the food packaging led to the development of active, intelligent and smart packaging materials able to improve the food quality, to increase the shelf life and to provide real time information about the condition of the food products. Although in the field numerous studies are continuously reported, there is still the need for the development of biocompatible, cost effective and highly performant systems easily scalable and applicable in everyday life. This thesis is focused on the development of active, and intelligent packaging biocomposite materials by utilizing functional fillers of natural origin, following cost effective, and easily scalable methods. Specifically, the first part of this study is focused on the modification of an already widely used polymer in food packaging, the low-density polyethylene, in order to improve its water vapor barrier properties and to transform it to a functional material with antioxidant properties, expanding thus its use in active packaging. This is succeeded by introducing into the polymer curcumin powder as filler, following the most common method for polyethylene processing used in industry, the melt processing. The developed composite shows excellent water vapor barrier and antioxidant properties making thus possible its use in active packaging for the shelf life increase of food products. In the second part of this study, an intelligent packaging porous indicator is developed by the combination of polyvinyl alcohol, microcrystalline cellulose and anthocyanins extracted from red cabbage. The specific material is able to indicate the food spoilage through a distinct color change that can be perceived by the naked eye and by non-expert users. In the third part of the present study, an smart packaging material is developed based on red cabbage powder and chitosan that combines the properties of both the active and intelligent packaging materials in a single system. The developed bioplastic presents excellent antioxidant activity, biodegradability and rapid color changes to the food’s pH fluctuations during the spoilage process indicating thus its quality deterioration.