Sonication-assisted protein isolation from apricot kernel press cake, combined with cyclotrichium niveum essential oil to produce and characterize an edible bioactive film

In this thesis study, protein isolate was obtained from Malatya apricot (Prunus armeniaca L.) kernel press cake by ultrasound-assisted extraction (US), and the usability of the obtained protein isolate in edible active film production was investigated. As a result of optimization using the Box–Behnken response surface methodology, protein yield and solubility were determined as 38,26±0,28% and 90,25±0,63%, respectively. US treatment improved the essential amino acid content and functional properties of the protein isolate. Protein subunits in the 17–20 kDa range were identified in the protein isolate obtained by US treatment. DSC results showed that US treatment preserved the thermal stability of the protein isolates. Cyclotrichium niveum essential oil exhibited antimicrobial activity against various pathogens. A composite film solution prepared using protein isolate and C. niveum essential oil was optimized, and the antioxidant activity and printability score of the optimum formulation were determined as 37,16±0,69% and 9,75± 0,07, respectively. Characterization of the films produced by casting and 3D food printing methods under optimum conditions revealed that 3D-printed films had lower thickness and opacity values. Additionally, SEM and FTIR analyses demonstrated the homogeneous distribution of the essential oil within the protein matrix. During storage studies conducted on Kashar cheese coated with the optimized film formulations, mold and yeast growth was suppressed in PI/EO-F-coated samples, and overall quality properties were better preserved, especially at low storage temperatures. According to shelf-life model results, PI/EO-F-coated cheese samples delayed TMAB growth and consequently extended shelf life, particularly at 15°C. It was concluded that edible active films containing apricot kernel protein isolate and C. niveum essential oil have the potential to extend the shelf life of cheese.