Active Thermoplastic Starch Film with Watermelon Rind Extract for Future Biodegradable Food Packaging

Abstract

Petrochemical plastic wastes generate serious environmental problems because they are resistant to natural decomposition. The aim of this study was to develop a biodegradable active thermoplastic film composed of polyvinyl alcohol (PVA), corn starch (ST), glycerol, and the active compounds from watermelon rind extract (WMRE), or PVA/ST/WMRE, using the casting technique. The film was examined for its mechanical, antioxidant, and functional properties against selected foodborne pathogens. The results showed that the addition of 10% v/v of watermelon rind extract to the film formulation significantly increased the tensile strength from 19.44 ± 0.84 MPa to 33.67 ± 4.38 MPa and slightly increased the percent elongation at break (% EAB) from 35.04 ± 0.96% to 35.16 ± 1.08%. The antioxidant property of PVA/ST/WMRE film was analyzed based on the DPPH scavenging activity assay, which significantly increased from 29.21 ± 0.24% to 63.37 ± 4.27%. The minimum inhibitory concentration (MIC) of watermelon rind extract was analyzed for the growth inhibition of Bacillus cereus ATCC 11778, Escherichia coli ATCC 8739, and Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311, with 10% (v/v) found as an optimal concentration against B. cereus. Wrapping fresh-cut purple cabbage with PVA/ST/WMRE film significantly reduced the microbial load after 3 days of storage, in comparison to commercial packaging (PET) and thermoplastic control film. Consumer testing of the packaging film indicated that user acceptance of the product was favorable. Therefore, we suggest that this newly developed film can be used as a biodegradable food packaging item that will lead to enhanced food safety, food quality, prolonged shelf life, and consumer acceptance for further food applications.

Influence of Epilobium parviflorum Herbal Extract on Physicochemical Properties of Thermoplastic Starch Films

“…This can be caused by the H-bonding formation between compounds from the extract with TPS. This H-bond crosslinking can also be responsible for changes in mechanical properties (higher TS and YM) [ 34 ]. Fingerprint peaks for the polysaccharide are in the range of 1200–900 cm −1 and are assigned to stretching C-O and C-C bonds as well as bending C-O-H groups from anhydroglucoside units of the polymer.…”

Production of Thermoplastic Starch-Aloe vera Gel Film with High Tensile Strength and Improved Water Solubility

“…According to Charles et al [ 8 ], potato peel starch can be used in the packaging of chilled and frozen foods. Meanwhile, Thodanakasem et al [ 9 ] used watermelon rind. Morphological structure, mechanical properties, thermal properties, barrier properties, and biodegradability were considered the standard characterization techniques for obtaining a high-quality starch-based film [ 1 , 10 , 11 , 12 , 13 , 14 ].…”

Supercritical CO2 Impregnation of Thymol in Thermoplastic Starch-Based Blends: Chemico-Physical Properties and Release Kinetics

“…The development of novel and biodegradable materials from renewable sources for different applications is the focus of scientific attention, primarily due to the raised awareness on the environmental impact of petroleum-based plastics, especially in the context of water, soil, and air pollution, as well as the increased omnipresence of microplastics [ 1 , 2 , 3 ]. It was shown that one of the promising alternatives to petroleum-based packaging plastics is starch due to its biodegradability, availability, renewability, and low cost [ 3 , 4 , 5 ]. Starch-based materials such as thermoplastic starch (TPS), with or without the addition of other biodegradable polymers, can be processed employing conventional equipment for the production of traditional thermoplastic materials and transformed by injection or blow molding into the final products suitable for food packaging [ 5 , 6 , 7 , 8 ].…”

“…This relates to packages containing additives that maintain or extend food quality or shelf-life and therefore contribute to the reduction in spoilage, food waste, food recalls, and foodborne illness outbreaks [ 10 ]. There are several reports on the preparation of TPS-based materials with bioactive components by conventional methods for the development of active food packaging [ 4 , 7 , 8 , 11 , 12 ]. These reports include the addition of watermelon rind extract to a water solution at 70 °C before solvent casting [ 4 ], the incorporation of TiO 2 nanoparticles by extrusion at 165 °C [ 7 ], and the addition of copper particles by thermocompression at 140 °C [ 12 ].…”

“…There are several reports on the preparation of TPS-based materials with bioactive components by conventional methods for the development of active food packaging [ 4 , 7 , 8 , 11 , 12 ]. These reports include the addition of watermelon rind extract to a water solution at 70 °C before solvent casting [ 4 ], the incorporation of TiO 2 nanoparticles by extrusion at 165 °C [ 7 ], and the addition of copper particles by thermocompression at 140 °C [ 12 ]. However, one of the methods that proved to be more efficient for the development of advanced materials is supercritical solvent impregnation (SSI).…”