Biodegradable and active-intelligent films based on methylcellulose and jambolão (Syzygium cumini) skins extract for food packaging

Natural and environmentally friendly molecules are high on demand in the development of active and intelligent food packaging, to decrease food deterioration and indicate the products freshness, while preventing nature pollution. Jambolão (Syzygium cumini) is rich in anthocyanins, known by their antioxidant properties and color changing in different pH environments. In the present study, active and pH-sensitive films were produced by the incorporation of jambolão skins extract in methylcellulose films. Packaging related properties, crystallinity, contact angles, microstructure and thermal properties were determined to identify the effects of different concentrations of jambolão skins extract (0, 10, 30 and 50%). pH-sensitivity properties were determined by changes in color over a pH range (1–10) and antioxidant activity was measured by the free radical scavenging ability. Biodegradability was determined in soil and sea water. Overall, incorporation of jambolão skins extract in methylcellulose films improved mechanical and barrier performance by increasing the cohesiveness of the matrix structures. Color changes occurred in films by altering pH because of the pH-sensitivity of anthocyanins structure. Radical scavenging assays showed that films incorporated with higher concentrations of jambolão skins extract presented similar scavenging ability as the pure extract. The active-intelligent films produced were biodegraded in sea water in two days and soil in 15 days. Such films offer the combined benefits to increase foods shelf life and indicate products freshness, at the same time that contribute to the decrease of environment pollution. Potential applications include meat and aquatic products, where lipid oxidation occurs, and the pH modification of the food is associated with spoilage. [Display omitted] •Great quantity of anthocyanins is present in jambolão (Syzygium cumini) fruit.•Anthocyanins are antioxidants with color changing properties under pH variation.•Jambolão skins extract was incorporated in methylcellulose films.•The methylcellulose films produced were active, intelligent, and biodegradable.•Such films can be used to increase foods shelf life and indicate products freshness.