Potato starch/sodium alginate composite film containing lycopene microcapsules for extending blueberry shelf life

Abstract

This study developed a novel biodegradable film using potato starch (PS) and sodium alginate (SA) as the substrate, incorporating lycopene microcapsules (LM) produced via the spray drying method as the functional component. The physiochemical properties of the film and its effectiveness in preserving blueberry freshness were systematically evaluated. SEM images and Raman spectra confirmed that the lycopene was fully encapsulated within the wall material, achieving a microencapsulation efficiency of 87.062 ± 2.341 %. Characterization of the films using SEM, ATR-FTIR, thermogravimetric analysis and X-ray diffraction revealed that lycopene was uniformly dispersed in the matrix and the crystallinity and thermal stability of the films were enhanced. Notably, the ABTS⁺∙ radical scavenging and UV-blocking abilities of the film improved proportionally with increasing LM content. At an LM concentration of 4.5 %, the film exhibited an antioxidant capacity of 46.264 ± 0.498 %. Furthermore, the inclusion of LM accelerated the film’s degradation rate in soil. Blueberry preservation experiments demonstrated that the film containing LM effectively slowed down the decline in blueberry hardness and total soluble solid content (TSS) and the rise in pH, thereby extending their shelf life. Overall, this study highlights the potential of lycopene in functional degradable food packaging materials, offering promising alternatives for sustainable food preservation.