Tania Garrido

Characterization of agar/soy protein biocomposite films: Effect of agar on the extruded pellets and compression moulded films

Agar/soy protein biocomposite films were successfully processed by extrusion and compression moulding, obtaining transparent and homogeneous films. The conformational changes occurred during the extrusion process and the effect of agar on the final properties were analyzed. As shown by differential scanning calorimetry (DSC) and specific mechanical energy (SME) values, during the extrusion process protein denatured and unfolded protein chains could interact with agar. These interactions were analyzed by Fourier transform infrared spectroscopy (FTIR) and the secondary structure was determined from the amide I band. Those interactions were supported by the decrease of film solubility. Furthermore, the good compatibility between agar and soy protein was confirmed by the images from scanning electron microscopy (SEM).

Development and characterization of cassava starch films incorporated with blueberry pomace

This work is focused on the development of renewable and biodegradable films by the valorisation of wastes from food processing industries, with the aim of contributing to the development of more sustainable films. In this context, different contents of blueberry pomace (BP) were incorporated into cassava starch (CS) film forming solutions and the functional properties of the films prepared by solution casting were investigated, specifically, thermal, optical and physicochemical properties. BP-incorporated films showed good barrier properties against light, indicating their beneficial effect to prevent food deterioration caused by UV radiation when these films are used for food packaging applications. These results were related to the presence of aromatic compounds in BP, which can absorb light at wavelengths below 300nm. Furthermore, all films maintained their structural integrity after immersion in water (24h) and the maximum swelling displayed was lower than 300%. Additionally, the release of active compounds from BP into food simulants (after 10days) showed higher migration into the acetic acid medium in comparison with the ethanol medium. Therefore, the incorporation of BP into CS film forming solution resulted in the improvement of film performance, suggesting the potential application of these films as active packaging.

Chicken feathers as a natural source of sulphur to develop sustainable protein films with enhanced properties

In this work, the effect of hydrolyzed keratin on the properties of soy protein-based films was analyzed when different manufacture processes were employed. It is widely known that the processing method selected can affect the film properties as a function of the structure obtained during the film formation. Therefore, the assessment of hydrolyzed keratin/soy protein films processed by casting and compression moulding was carried out by means of the analysis of physicochemical, thermal, mechanical, optical and surface properties. It was observed that the incorporation of hydrolyzed keratin, obtained from a simpler, environmentally friendlier and more sustainable extraction method, resulted in the improvement of the thermal stability of the films, irrespective of the processing method employed. Moreover, the films processed by compression moulding showed enhanced tensile strength, which increased with the incorporation of hydrolyzed keratin due to the formation of disulfide bonds.

Versatile soy protein films and hydrogels by the incorporation of β-chitin from squid pens (Loligo sp.)

This study is focused on the preparation and characterization of β-chitin reinforced soy protein films, employing compression moulding as the processing method. β-chitin was extracted from squid pens (Loligo sp.) by a simple alkaline hydrolysis, avoiding the demineralization and decolouration steps used in chitin extraction from other sources, thus reducing the processing time and the production costs of the films. β-chitin was homogenously incorporated into the soy protein matrix, indicating good compatibility between the protein and the polysaccharide. Furthermore, the tensile strength and modulus of the films were significantly improved with the β-chitin addition due to the increase in crystallinity. Regarding the water uptake of the films, equilibrium was achieved in the first four hours of immersion and film integrity was maintained during the entire immersion time, suggesting the interactions among the film forming components; additionally, film solubility decreased with β-chitin concentration. Therefore, a promising multifunctional material was developed in this study.

The Potential of Vegetal and Animal Proteins to Develop More Sustainable Food Packaging

Vegetal and animal proteins have been considered promising alternatives to develop new sustainable food packaging derived from bio-resources. Edible, easy to process, renewable and environmental friendly are just a few characteristics that turn proteins into excellent raw materials to develop edible or biodegradable films. Furthermore, the valorization of industrial wastes or by-products to develop more sustainable films could add value to these products. In this context, food processing industries generate wastes that cause economic and environmental problems; therefore, the valorization of these wastes to obtain proteins could facilitate the waste management as well as the development of value-added products. Despite these environmental benefits, vegetal and animal proteins have some drawbacks and different strategies are explored to overcome those limitations for their use as food packaging. Taking this into account, the aim of this chapter is to provide an overview of the currently developed films and coatings based on animal and vegetal proteins, including active packaging.

Extraction and incorporation of bioactives into protein formulations for food and biomedical applications

Bioactive compounds from natural resources have been pointed out as promising substances with great benefits for human health. Furthermore, new techniques for their extraction have been reviewed in order to consider a global approach taking economic and environmental issues into account. Additionally, the incorporation of these biologically active compounds into protein-based products manufactured via different processing methods, such as solution casting, compression moulding, electrospinning, freeze-drying, and 3D printing, has been assessed, since the design and manufacturing method employed have a direct influence into the final properties of the material. Hence, new opportunities to develop active biopolymeric materials with great potential in food and biomedical applications have been presented. This review aims to provide an overview of some advanced technologies employed for bioactive extraction, as well as the bioactives incorporation into protein formulations to produce biomaterials and food packaging.