Use of biopolymer based food packaging films in determining food freshness

In this thesis study, it was aimed to develop and characterise environmentally friendly, biopolymer-based smart food packaging films that can be used as an alternative for determining food freshness. By mixing carboxy methyl cellulose (CMC) (2%, v/v) and polyvinyl alcohol (PVA) (8%, v/v) polymer solutions at a 1:1 ratio in the presence of glycerol (30% of the total biopolymer weight) CMC:PVA active control films were prepared by casting technique. pH sensitive anthocyanins were used as pH indicator material to determine the food freshness of biopolymer films. Industrial aronia fruit juice pulp was used as an anthocyanin source to reuse the environmental waste and aronia pulp powder extracts (APTE) were obtained by optimising the ultrasonic extraction method conditions. Since the stability of anthocyanins decreases due to external factors such as light and temperature, more stable microencapsulated aronia powder extracts (MAPTE) were synthesised by forming molecular inclusion complexes with βcyclodextrins. Encapsulation efficiency was found as 51% by spectroscopic method and 52% by chromatographic method. FTIR, UV-Vis spectroscopy, DSC analysis and SEM images proved the formation of capsules. The time and temperature dependent changes of APTE and xix MAPTE