THE EFFECT OF pH LEVEL, HOMOGENIZATION METHODS, AND UV-C RADIATION ON THE STRUCTURAL AND FUNCTIONAL PROPERTIES OF VARIOUS POLYSACCHARIDE-PROTEIN BASED ACTIVE FOOD PACKAGING MATERIALS

2023-10-20
Ertan, Kübra
Biopolymers derived from natural resources are sustainable alternatives to petrochemical-based plastic food packaging regarding to health and environmental concerns. Food quality and safety can be improved by active packaging with bioactive substances. The hydrophobic nature of biopolymers, their high-water vapour permeability (WVP), and low mechanical durability restrict their applications. In this study, different modification methods including pH adjustment (7, 9, and 11), gallic acid (GA) and pomegranate peel powder (PP) addition, ultrasonication (160 W, 20 kHz, 10 min), and ultraviolet irradiation (254 nm, 10 J/cm2) were used to enhance the properties of polysaccharide-protein films produced by casting. The sesame protein-common vetch starch (SC) films were prepared at different pHs with/without GA. When pH increased from 7 to 9 and 11, the WVP of SC films decreased by 22.7% and 26.7%, respectively. The lowest WVP, the highest thermal stability, darker and more compatible structure were observed in SC-GA films at pH 9. Similarly, GA with mild alkalinity provided a reduction in WVP, more opaque appearance, and enhanced thermal stability for peanut protein-corn starch (PC) films. The crosslinking degrees of PC-GA films were 49.1% (pH 7), 77% (pH 9), and 67.4% (pH 11). Moreover, GA addition resulted superior antioxidant activity at pH 7. The SC-PP films exhibited higher antibacterial effects on E.coli than S.aureus and L.monocytogenes, and higher tensile strength (47-146%) than SC. The highest tensile strength (5.62 MPa) was observed after UV-C treatment. Enrichment with GA (pH 9) and PP are recommended for biopolymer film stability and active packaging applications, respectively.
Citation Formats
K. Ertan, “THE EFFECT OF pH LEVEL, HOMOGENIZATION METHODS, AND UV-C RADIATION ON THE STRUCTURAL AND FUNCTIONAL PROPERTIES OF VARIOUS POLYSACCHARIDE-PROTEIN BASED ACTIVE FOOD PACKAGING MATERIALS,” Ph.D. - Doctoral Program, Middle East Technical University, 2023.