Chitosan‐nanocomposites as a food active packaging: Effect of addition of tocopherol and modified montmorillonite

Abstract

The development of natural biodegradable polymers to partially or totally replace synthetic polymers may be advantageous in food packaging, mainly when are associated with additional features such as active packaging. This article aimed to evaluate the effect of tocopherol concentration (0, 5, 10, and 20%) and modified montmorillonite clay (MMT15A) nanoparticles (0 and 1%) on the properties of chitosan (CS) films. The addition of tocopherol provided antioxidant activity and improved the thermal stability of the films, and acted as a plasticizer, decreasing the tensile strength, elastic modulus, and glass transition temperature of the films. Although MMT15A and tocopherol did not change the water vapor permeability, an improvement of the mechanical strength and lower equilibrium moisture content was observed when compared to the treatment made with CS alone. Both MMT15A and tocopherol allowed the production of bio‐nanocomposites with thermal, morphological, mechanical, and water‐resistant properties to be used as an antioxidant in packaging materials. Practical Applications The films containing both montmorillonite (MMT15A) and tocopherol presented an improved mechanical strength, thermal stability, and antioxidant activity when compared to the films containing the only tocopherol. Therefore, it was possible to develop antioxidant chitosan films with improved properties using up to 20% tocopherol and MMT15A. At this tocopherol and MMT 15A concentrations, the films may also be used to nutritionally enrich food, adding value to the package and the conditioned product. Furthermore, the films can also be considered edible films with combined properties.

Properties of films and coatings added of tocopherol for food packaging: tool-based review for systematic reviews and bibliometric analysis

“…In the analyzed works, the increase in the opacity of the films was also widely reported (Darbasi et al, 2017;Sun et al, 2017a;P erez-C ordoba et al, 2018;Hamid et al, 2019a;Yeamsuksawat and Liang, 2019;Agudelo-Cuartas et al, 2020;Zhang et al, 2020a, b;Dias et al, 2021;Rosenbloom and Zhao, 2020); however, two articles reported a decrease in this parameter (Lopes et al, 2020;Mirzaei-Mohkam et al, 2020). The transparency was attributed to interference in the organization of the matrix, creating irregularities and favoring the transmission of light with an effect on the compaction of the polymeric network, increasing the free spaces.…”

“…, 2019a; Yeamsuksawat and Liang, 2019; Agudelo-Cuartas et al. , 2020; Zhang et al ., 2020a, b; Dias et al. , 2021; Rosenbloom and Zhao, 2020); however, two articles reported a decrease in this parameter (Lopes et al.…”

“…, 2020b). However, chitosan films developed with different concentrations of montmorillonite nanocomposites added with 20% tocopherol showed heterogeneous characteristics (Dias et al. , 2021).…”

“…Freitas et al (2022) stated that a contact angle below 908 denotes a low surface tension, so the lower the wettability, the more hydrophobic the surface. It is noted in the articles that the addition of α-tocopherol to the films or coatings produced polymers with greater hydrophobicity (de Carvalho et al, 2019;Dias et al, 2021) and hydrophilicity (Ferreira et al, 2021;Jiang et al, 2021). For use in food packaging, the film or coating must be more hydrophobic to function as a barrier to water, as greater humidity can cause deterioration of the food product-the incorporation of α-tocopherol precisely to combine a hydrophobic compound with the polymer matrix to increase hydrophobicity.…”

Chitosan Based Biodegradable Composite for Antibacterial Food Packaging Application

“…The RSO improved the mechanical, gas, and water vapor barrier properties and antioxidant activity [ 104 ]. Additional studies also showed that MMT and tocopherol improved chitosan film’s mechanical properties, thermal stability, and antioxidant activity [ 105 ].…”