Effect of low concentrations of SiO2 nanoparticles on the physical and chemical properties of sodium alginate-based films.

This work investigated the effect of adding low concentrations of nano-SiO2 (0.5, 1.0 and 1.5%) in the properties of films based on sodium alginate, to identify lower thresholds in the proportion of the reinforcing agent. It was found that, even in the smallest proportion, thermal stability of the nanocomposites improved significantly (with degradation onset increased by almost 15% compared with the control film). The surface morphology showed pronounced roughness at nano-SiO2 concentrations greater than 1.0%, indicating agglomeration of part of the nanomaterial. Mechanical properties were reduced for the samples with concentrations equal to 1.0 and 1.5%, however, without significant differences between them. Conversely, water vapor and light barrier properties have not undergone significant changes in any formulation. Therefore, the use of 0.5% nano-SiO2 in alginate films would be an easy and economically interesting way to improve thermal stability, without significantly reducing mechanical properties of the pure material.

Furcellaran: An innovative biopolymer in the production of films and coatings.

Seaweed is a prominent source of polysaccharides with extraction processes properly established, allowing to employ them in several areas. Among all the types of biopolymers obtained from seaweed, furcellaran has gained notoriety in recent years. This is due to its abundance, water solubility and outstanding film-forming abilities. Despite still being little studied, in several works, remarkable advances in terms of improving properties of furcellaran-based films have been described in the literature. However, there are still numerous research opportunities to be explored regarding the improvement of material properties. Therefore, the objective of this review is to highlight the innovative method in preparation, characterization and performance of furcellaran-based films as food packaging. This is the first study in which current results in the area are presented. Initially, it concerns biopolymer chemical and extraction insights. In addition, a comprehensive description of the advances in film properties is outlined (from mechanical to active/intelligent responses). Ultimately, challenges and future prospects are also discussed.

Kefiran-based films: Fundamental concepts, formulation strategies and properties.

Concerns about plastic pollution have driven research into novel bio-derived and biodegradable polymers with improved properties. Among the various classes of biopolymers studied, kefiran films only have gained emphasis in recent years. Its film-forming ability and outstanding biological activities illustrate its potential for active packaging applications. However, despite recent advances, the key challenge is still associated with obtaining high water vapor barrier and better mechanical properties. In that fashion, this review highlights for the first time the cutting-edge advances in the preparation, characterization and enhancement of the packaging performance of kefiran-based films. The fundamental concepts of the biopolymer production and chemical analysis are previously outlined to direct the reader to the structure-property relationship. In addition, this research critically discusses the current challenges and prospects toward better material properties.

Effect of high-pressure processing on characteristics of flexible packaging for foods and beverages.

High-pressure processing is an emerging food preservation technology that causes minimal product quality loss: Food packaged and high-pressure processed keep most of their nutritional qualities, in addition to extending their shelf life. However, the selection of packaging materials suitable for this technology becomes extremely important, since processing can cause changes in the visual aspects and in the physicochemical and mechanical properties of the materials, compromising the shelf life and safety of high-pressure processed foods somehow. Some studies have evaluated the effect of this technology on the properties and the migration and diffusion potential of intentional substances and of polymeric components in some flexible multilayer laminated packaging. Within this context, an important and relevant issue for industrial applications is knowing the possible effects of the parameters of high-pressure treatments, in low and high temperature, on the structure and morphology of materials that, in turn, can determine the relevant effects on the mechanical, barrier, and thermal properties and the migration and diffusion potential of intentional and non-intentional substances. Our study aims to make a literature review on the requirements of flexible packaging materials that can be used in high-pressure processing and the state of the art and the knowledge of the effects of different processing conditions on their properties.

Evaluation of extra virgin olive oil stability by artificial neural network.

The stability of extra virgin olive oil in polyethylene terephthalate bottles and tinplate cans stored for 6 months under dark and light conditions was evaluated. The following analyses were carried out: free fatty acids, peroxide value, specific extinction at 232 and 270 nm, chlorophyll, L(∗)C(∗)h color, total phenolic compounds, tocopherols and squalene. The physicochemical changes were evaluated by artificial neural network (ANN) modeling with respect to light exposure conditions and packaging material. The optimized ANN structure consists of 11 input neurons, 18 hidden neurons and 5 output neurons using hyperbolic tangent and softmax activation functions in hidden and output layers, respectively. The five output neurons correspond to five possible classifications according to packaging material (PET amber, PET transparent and tinplate can) and light exposure (dark and light storage). The predicted physicochemical changes agreed very well with the experimental data showing high classification accuracy for test (>90%) and training set (>85). Sensitivity analysis showed that free fatty acid content, peroxide value, L(∗)Cab(∗)hab(∗) color parameters, tocopherol and chlorophyll contents were the physicochemical attributes with the most discriminative power.