Modulation effect of glycerol on plasticization and water distribution of vacuum-dried calcium alginate gel beads encapsulating peppermint oil/β-cyclodextrin complex

Development and Characteristics of Protein Edible Film Derived from Pork Gelatin and Beef Broth

The aim of this work was to develop edible films derived from gelatin and beef broth and to analyze the physical properties of the output products. The presented research is important from the point of view of searching for food packaging solutions that may replace traditionally used plastic packaging. This study's conceptual framework is in line with the trend of sustainable development and zero waste. This study was conducted to develop a recipe for edible films derived from beef gelatin with gelatin concentrations at 4%, 8%, and 12% enriched with additions of beef broth in amounts of 25, 50, 75, and 100%. Selected physical properties of the output edible films were examined in terms of thickness, swelling in water, opacity, water content, water solubility, structure, and mechanical properties. The conducted research made it plausible to conclude that the addition of broth has a positive effect on the extensibility of the edible films and the other physical properties under consideration, especially on decreasing the film thickness, which was found to vary between 50.2 and 191.6 µm. When gelatin and broth were added at low concentrations, the tensile strength of the films increased, and subsequently decreased; however, an opposite effect was observed for elongation at break. The increased broth concentration caused the film opacity to increase from 0.39 to 4.54 A/mm and from 0.18 to 1.04 A/mm with gelatin concentrations of 4% and 12%, respectively. The water solubility of the gelatin films decreased as a result of the broth addition. However, it was noticed that increasing the content of broth caused the water solubility to increase in the tested films. The mere presence of broth in the gelatin films changed the microstructure of the films and also made them thinner.

Investigation of the Structure-Forming Potential of Protein Components in the Reformulation of the Composition of Edible Films

To optimize the functional properties of edible films or coatings, mixtures of several ingredients are used, including food processing by-products. In this way, pectin from fruit pomace, whey proteins from whey as a by-product of rennet cheese production, and gelatin from by-products of the processing of slaughtered animals can be obtained. The aim and scope of the investigation were to verify the hypothesis of the research, which assumes that the addition of beef broth to edible gelatin films will affect the gelation processes of the tested film-forming solutions and will allow for the modification of the edible properties of the films obtained based on these solutions. Measurements were carried out to determine the visual parameters, mechanical strengths, surface and cross-sectional structures, FTIR spectra, thermal degradation rates, and hydrophilicities of the prepared gelatin films. The water content, water vapor permeability, and course of water vapor sorption isotherms of the films were also examined, as well as the course of the gelation process for film-forming solutions. The addition of broth to film-forming solutions was found to increase their opacity and color saturation, especially for the ones that were yellow. The films with the addition of broth were more uneven on the surface and more resistant to stretching, and in the case of the selected types of gelatins, they also formed a more stable gel. The broth increased the hydrophilicity and permeability of the water vapor and reduced the water content of the films. The addition of broth enables the practical use of edible films, but it is necessary to modify some features.

3D Printing of smart labels with curcumin-loaded soy protein isolate

A two-step method for preparing smart labels that can monitor food freshness through color change is presented. The conventional casting method for such labels is not cost-effective, as it uses organic solvents and requires additional cutting processes. Our method is more eco-friendly and customizable, as it uses water as the sole solvent and 3D printing as the fabrication technique. First, curcumin was encapsulated with soy protein isolate (SPI) by a pH-driven method involving hydrogen bonding and hydrophobic interactions. Subsequently, the SPI-curcumin complex was blended with gelatin to create a printable ink. The ink has suitable rheological properties for extrusion, with a yield stress of 400-600 Pa and a viscosity of 122.93-142.82 Pa·s at the optimal printing temperature. The complex modulus of the ink increases to above 2 × 103 Pa when cooled to 25 °C, indicating rapid gel formation. The application of these smart labels to minced meat demonstrated their ability to reflect its freshness by transitioning from yellow to red. Furthermore, the printability and mechanical properties of the labels can be adjusted by changing the glycerol/water ratio. This innovative approach is a promising solution for producing environmentally friendly and customizable smart labels for food freshness monitoring.

Ethanol-free Cross-Linking of Alginate Nanofibers Enables Controlled Release into a Simulated Gastrointestinal Tract Model

The use of alginate nanofibers in certain biomedical applications, including targeted delivery to the gut, is limited because an ethanol-free, biocompatible cross-linking method has not been demonstrated. Here, we developed water-stable, alginate-based nanofibers by systematically exploring post-electrospinning cross-linking approaches that used calcium ions dissolved in (1) a glycerol/water cosolvent system and (2) acidic, neutral, or basic aqueous solutions. Scanning electron microscopy proved that the fibers cross-linked in a glycerol cosolvent or pH-optimized solutions had maintained the same morphology as the ethanol-based literature control. Notably, cross-linked fibers were generally smaller in diameter than the as-spun fibers due to both chemical interactions and mass loss during cross-linking, which was supported by mass measurements, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. During stability tests wherein the cross-linked fibers were exposed to three aqueous solutions, the cross-linked fibers were stable in water and acid buffer yet swelled in phosphate buffer saline, making them useful scaffolds for pH-controlled release applications. Proof-of-concept release experiments were conducted using a simulated gastrointestinal tract model. As desired, the cargo remained encapsulated within the cross-linked nanofibers when exposed to an acidic solution that modeled the stomach. Upon exposure to a solution that mimicked the intestines, the cargo was released. We suggest that these cross-linked, alginate-based nanofiber mats hold the potential to be broadly used in biomedical and environmental applications.

Potential Food and Nutraceutical Applications of Alginate: A Review

Alginate is an acidic polysaccharide mainly extracted from kelp or sargassum, which comprises 40% of the dry weight of algae. It is a linear polymer consisting of β-D-mannuronic acid (M) and α-L-guluronic acid (G) with 1,4-glycosidic linkages, possessing various applications in the food and nutraceutical industries due to its unique physicochemical properties and health benefits. Additionally, alginate is able to form a gel matrix in the presence of Ca²⁺ ions. Alginate properties also affect its gelation, including its structure and experimental conditions such as pH, temperature, crosslinker concentration, residence time and ionic strength. These features of this polysaccharide have been widely used in the food industry, including in food gels, controlled-release systems and film packaging. This review comprehensively covers the analysis of alginate and discussed the potential applications of alginate in the food industry and nutraceuticals.