Linden-based mucilage biodegradable films: A green perspective on functional and sustainable food packaging

This study focuses on the utilization of linden mucilage, extracted from the linden tree, as a potential natural polymer source for the production of composite films. The films, which incorporating linden water extract, essential oil, and oil, exhibited improved thermal stability, surface morphology, and water resistance. Biodegradability assessments, particularly for films using essential oil and oil, showed promising outcomes by maintaining structural integrity. Antimicrobial assays demonstrated significant resistance against pathogens, indicating potential applications requiring microbial resistance. Mechanical analyses revealed a trade-off between tensile strength and elongation at break with addition of components. Composite films exhibited reduced water vapor permeability which correlate with water solubility and contact angle measurements. Soil biodegradation studies highlighted the films' potential to mitigate environmental impact. Cytotoxicity tests confirmed the safety of these films for potential food applications. Additionally, antioxidant assays showed increased radical scavenging activity in films with added components. In conclusion, linden-based composite films exhibit promising characteristics, suggesting their potential as sustainable and functional materials, particularly for use in food packaging.

UV-blocking biodegradable film based on flaxseed mucilage/pectin impregnated with titanium dioxide and calcium chloride for food packaging applications

A UV blocking and potentially biodegradable composite films are fabricated from flax seed mucilage and pectin with different concentrations of titanium dioxide (TiO₂) and crosslinked with calcium chloride (CaCl₂). This study aimed to evaluate the physical, surface, and optical properties including color, potential biodegradability, and absorption kinetics of the developed film. From the observations made, addition of 5 wt% TiO₂ enhanced UV barrier property with a total color change (ΔE) of 23.441 ± 0.54 and increased its crystallinity to 54.1 % from 43.6 %. Crosslinking agent and TiO₂ resulted in a prolonged period of biodegradation of >21 days when compared to neat film. Also, swelling index of crosslinked film was reduced by 3 times of non-crosslinked films. Surface of the developed films has no cracks and agglomerates as observed from scanning electron microscope. Moisture absorption kinetic study reveals that all the films have best-fit data following a pseudo-second-order kinetic model with a correlation coefficient ≥0.99 and the rate was controlled by inter-particle diffusion. The film with 1 wt% TiO₂ and 5 wt% CaCl₂ showed the lowest rate constants (k₁) of 0.27 and (k₂) of 0.029. The results suggest that this film can be potentially used in food packaging as a UV-blocking layer with potential biodegradability and good moisture resistance as compared to pure flax seed mucilage or pectin films.

Production and Characterization of Biocomposite Films of Bacterial Cellulose from Kombucha and Coated with Chitosan

The purpose of this research is to produce and characterize bacterial cellulose (BC) films coated with chitosan (BC-CH). BC films were produced in a fermentation medium based on Camellia sinensis tea and dextrose (12 days at 25 °C) and subsequently treated with coating-forming solutions (CFSs) based on chitosan (BC-CH 0.5%, BC-CH 1.0%, and BC-CH 1.5%). As a result, the FTIR spectra of BC and BC-CH 1.5% showed the main characteristic bands of cellulose and chitosan. In the physicochemical characterization of the films, it was found that the incorporation of the chitosan coatings did not affect the thickness; however, it decreased the luminosity (L*) and increased redness (a*), yellowness (b*), and opacity (75.24%). Additionally, the light absorption properties in the UV-Vis range were improved. Furthermore, the application of the CFSs increased: the solubility (64.91%), the antimicrobial activity against S. aureus (6.55 mm) and E. coli (8.25 mm), as well as the antioxidant activity (57.71% and 24.57% free radical scavenging activity), and the content of total phenols (2.45 mg GAE/g). Finally, our results suggest that the BC-CH films developed in the present study show a potential application as active packaging material for food.

Mucilages: sources, extraction methods, and characteristics for their use as encapsulation agents

The increasing interest in the use of natural ingredients has driven keen research and commercial interest in the use of mucilages for a range of applications. Typically, mucilages are polysaccharide hydrocolloids with distinct physicochemical and structural diversity, possessing characteristic functional and health benefits. Apart from their role as binding, thickening, stabilizing, and humidifying agents, they are valued for their antimicrobial, antihypertensive, antioxidant, antiasthmatic, hypoglycemic, and hypolipidemic activities. The focus of this review is to present the range of mucilages that have been explored as encapsulating agents. Encapsulation of food ingredients, nutraceutical, and pharmaceutical ingredients is an attractive technique to enhance the stability of targeted compounds, apart from providing benefits on delivery characteristics. The most widely adopted conventional and emerging extraction and purification methods are explained and supplemented with information on the key criteria involved in characterizing the physicochemical and functional properties of mucilages. The unique traits and benefits of using mucilages as encapsulation agents are detailed with the different methods used by researchers to encapsulate different food and bioactive compounds.