Effect of drying temperature and extent of particle dispersion on composite films of methylcellulose and zein nanoparticles

Development and characterization of cellulose nanofiber reinforced hydroxypropyl methylcellulose films functionalized with propolis-loaded zein nanoparticles and its application for cheddar cheese storage

Cellulose nanofiber (CNF) reinforced hydroxypropyl methylcellulose (HPMC) films were functionalized with propolis-loaded zein nanoparticles (ZNP) to develop active, printable, and heat-sealable films. The films with 0, 0.10, 0.25, 0.50, or 0.75 mg/mL propolis-loaded ZNP, named 0ZNP, 0.10ZNP, 0.25ZNP, 0.50ZNP, and 0.75ZNP, respectively, were characterized for their mechanical, physicochemical, structural, functional and optical properties and antioxidant activity. The addition of propolis-loaded ZNP did not change tensile strength (P > 0.05), but increased elongation at break (from 24.72 to 36.58 %) (P < 0.05) for 0.25ZNP film. A water contact angle increased significantly (P < 0.05) for 0.50ZNP (~45 %) and 0.75ZNP (~137 %) films. The 0.25ZNP and 0.75ZNP films were evaluated for packaging cheddar cheese under refrigerated storage for 30 days, and resulted in comparable water activity, pH, titratable acidity, and lipid oxidation (P > 0.05) with those packaged by LDPE film and vacuum package. The developed films can function as eco-friendly alternatives to single-use plastic food packaging.

Design and Fabrication of Epichlorohydrin-Cross-Linked Methyl Cellulose Aerogel-Based Composite Materials for Magnetic UV Response Light-to-Heat Conversion and Storage

The collection, storage, and use of energy and information are important issues for overcoming the global energy shortage while satisfying the demand for information transmission. This research reports a nano-Fe₃O₄ and erythritol (ER)-functionalized, cross-linked methyl cellulose aerogel (MC-EP) composite that has the characteristics of phase-change energy storage as the magnetic and ultraviolet responses requisite for light-to-heat conversion and storage. The nano-Fe₃O₄ particles in MC-EP-ER-75 were fixed and filled into pore structures in MC-EP. ER was used to form an effective combination with MC-EP. The addition of nano-Fe₃O₄ compensated for the low thermal conductivity of ER. The MC-EP-ER-75 was able to store solar radiation-induced energy due to the loading of ER at a photothermal conversion efficiency of 79.67% and a light-to-heat conversion efficiency of 79.67%. The results of thermal stability (TGA) analysis showed that MC-EP-ER-75 was thermally degraded acceptably below 200 °C. The differential scanning calorimetry curve and latent heat values (melting/crystallization enthalpies of 314.8 and 197.9 J/g, respectively) of MC-EP-ER-75 did not change after 100 cycles. In addition, it exhibited excellent saturation magnetization, super-paramagnetism, and ultraviolet shielding, as well as a rapid response to the ultraviolet and magnetic fields. This provided a way to prepare light-to-heat conversion-storage-release materials and ultraviolet-magnetic sensors that can be used in renewable resources.

Fabrication and Characterization of Lutein-Loaded Nanoparticles Based on Zein and Sophorolipid: Enhancement of Water Solubility, Stability, and Bioaccessibility

Lutein is a hydrophobic carotenoid with various beneficial biological activities. Its use as a functional food, however, is currently limited by its low-water solubility, chemical instability, and poor bioavailability. The purpose of this work is to fabricate lutein-loaded nanoparticles to overcome these challenges. Lutein was encapsulated in zein nanoparticles coated with sophorolipid (ZSLNPs). The properties of ZSLNPs were characterized by transmission electron microscopy and dynamic light scattering. The results showed that the ZSLNPs were spheres with particle size around 200 nm and negative surface potentials (ζ = -54 mV). The encapsulation efficiency and loading capacity of the lutein in the ZSLNPs was 90.04% and 0.82%, respectively. Infrared spectroscopy analysis indicated that the dominant driving forces of the ZSLNPs formation mainly included electrostatic, hydrophobic interactions and hydrogen bonding. X-ray analysis showed that the encapsulated lutein was in an amorphous form. Circular dichroism analysis suggested that the incorporation of lutein or sophorolipid led to the change in secondary structure of zein. In addition, the ZSLNPs had good stability, redispersibility, and increased the water solubility of lutein. Furthermore, in vitro studies showed that the ZSLNPs had great biocompatibility and bioaccessibility of lutein. Overall, these findings indicated that the core/shell nanoparticles developed in the work may be suitable for encapsulating this important nutrient in functional foods.