Sandra Rivero; Javier Lecot; Adriana Pinotti
Abstract
PLA coating on Kraft paper is very promising systems for food packaging, and has potential environmental advantages over conventional synthetic paper coatings. This work was focused on: (i) analyzing the physicochemical, thermal and microstructural properties of PLA films; (ii) developing and studying ...
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PLA coating on Kraft paper is very promising systems for food packaging, and has potential environmental advantages over conventional synthetic paper coatings. This work was focused on: (i) analyzing the physicochemical, thermal and microstructural properties of PLA films; (ii) developing and studying multilayer systems obtained by impregnation of Kraft paper with different layers of PLA solution; (iii) evaluating the influence of PLA layers on the support cellulosic properties. The PLA coating improves packaging material performance and hence the functional properties of Kraft paper. The impregnation of hygroscopic materials as the Kraft paper with PLA was an alternative interesting to obtain more hydrophobic matrices. The assembled materials attained were heat-sealed. Furthermore, the use of PLA adds to potential food applications, a renewable resource value obtained from sources agricultural. The design of this multilayer support also allows its extension to other media such as paperboard. Moreover, the addition of 4 or 5 layers favourably modified the assembled system properties. Increasing even further the number of PLA layers, system properties hardly underwent a significant improvement. Consequently, the selection of the number of PLA layers would be a response to a relationship of commitment between the increase in the cost and the enhancement of the properties.
Sandra Rivero; Maria A. Garcia; Adriana Pinotti
Abstract
The influence of natural antioxidants incorporated to biodegradable materials has become a focus of attention in the current food packaging research and development. Chitosan is a functional natural polymer extensively used for tailoring systems or matrices for a different active compound delivery. This ...
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The influence of natural antioxidants incorporated to biodegradable materials has become a focus of attention in the current food packaging research and development. Chitosan is a functional natural polymer extensively used for tailoring systems or matrices for a different active compound delivery. This work was focused on studying the changes undergone by the chitosan matrix because of the addition of ferulic acid as an antioxidant. Thus, both microstructure and physical properties such as solubility, thermal stability, mechanical and barrier properties were monitored. The addition of ferulic acid caused a decrease in both the moisture content and water vapor permeability, an increase in resistance and a change at the structural level evidenced by TEM. Through FTIR spectra and their relationship with chitosan-based film properties, it was demonstrated that ferulic acid was effectively incorporated in the polymer matrix. The amount of the bioactive compound released from the chitosan matrix to a liquid medium was determined. The delivery profile suggested that the release of the antioxidant agent was controlled by two parallel mechanisms, one Fickian-type and the other associated to the high swelling of the matrix. The antioxidant and UV-barrier properties induced by the addition of ferulic acid turned the chitosan films into a potentially active material to be applied on high-fat foods.