Novel active composite films based on carboxymethyl cellulose and sodium alginate incorporated with phycocyanin: Physico-chemical, microstructural and antioxidant properties

Phycocyanin (PC) has been demonstrated to be an excellent source of antioxidant activities. The antioxidant capacity of biopolymer based packaging films should be enhanced with PC incorporation. For further elucidation of this hypothesis, edible packaging films were prepared by adding PC into carboxymethyl cellulose (CMC), sodium alginate (SA), and their combination (CMC/SA), respectively. The effects of PC addition on morphological and physico-chemical properties were investigated. Meanwhile, the antioxidant capacity including DPPH and ABTS radical scavenging activity were also determined. The results depicted that the moisture content, water solubility, water vapor and oxygen permeability of the films were decreased, but thickness was increased by the addition of PC. The tensile strength, elongation at break, and elastic modulus were also improved. The transparency of PC added films was reduced due to blue color of PC. Scanning electron microscopic analysis showed that the surface of the film was homogenous for the control but cracks were noted in PC added films, which improved the film structure. A good physical interaction was reflected by Fourier transform infrared spectroscopy analysis among CMC, SA, and PC. Moreover, the antioxidant capacity also showed enhanced trend depending on increasing concentration of PC. Therefore, PC incorporation into CMC and/or SA based film was an efficient manner to produce eco-friendly and active edible packaging films for fresh food preservation application.