Intelligent packaging film fortified with betacyanin for prolonging rice cake freshness

Abstract

Synthesis of active biodegradable packaging materials with antibacterial and antioxidant components to improve food’s shelf life has gained momentousness in recent research area. Hence, a commixture of spherical-shaped ZnO-TiO₂ nanoparticles (NP-37 nm) was prepared and bounded with kitchen-waste bio-composites (garlic peel and beetroot stem). The hybrid mixture incorporated with polyvinyl alcohol and glycerol was cast into films R1 (NP-0.01 g), R2 (NP-0.015 g), and R3 (NP-0.02 g). The NP was inspected using XRD, TEM (SAED with d-spacing-2.81 Å), FESEM and EDS. UV analysis confirms the presence of betacyanin (500–550 nm) from the treated beetroot stem extract. The prepared films were found to have bacterial load enumeration ≤ 17 cfu/g. The barrier properties such as UV barrier, opacity (R2-30.3%) and increasing hydrophobicity with NP ratio were studied. Functional parameters of the prepared films like water vapour transmission rate (≤ 2.56 g/cm²/day), moisture content (R3-26.04%), solubility (≤ 30.91%), soil degradation, etc. were examined. The band gap of films was calculated as R1-4.88 eV, R2-5.06 eV and R3-5.21 eV confirming their insulating nature. The real-time analysis of the freshness and continuance of steamed rice cakes was observed from the film’s colour change with the change in the pH level, interpreting its quality and enhanced shelf-life. The research supported by statistical analysis highlights the significance of betacyanin (colour indication) and added NP (novel admixture) as a smart biodegradable film. “Intelligent film”—a valid substitute for non-degradable plastics, and a potential retainment of the freshness of putrescible food by 60% could be recommended in storing food in industries.