Antioxidant polysaccharide/gelatin blend films loaded with curcumin - A comparative study.

Curcumin (CUR; 0, 0.005, 0.01, 0.02 %) was loaded into binary 75/25 blend films based on polysaccharides (carboxymethyl cellulose (CMC), gum Arabic (GAR), octenyl succinic anhydride modified starch (OSA), water-soluble soy polysaccharides (WSSP)) and gelatin (GEL). The GAR-based system was the least rough and, consequently, the most transparent of the films. An opposite result was found for the WSSP-based film. Despite the phase separation, the CMC75/GEL25 film exhibited excellent mechanical strength and stiffness. CUR improved the UV/VIS light-barrier characteristics of the films, but did not affect most of other physiochemical properties. X-ray diffractograms revealed that CUR provoked the rearrangement of the triple helical structure of GEL. As highly erodible, the CMC75/GEL25 carrier ensured the fastest and the most complete release of CUR. The OSA75/GEL25 system exhibited an opposite behavior. The kinetic profiles of the antiradical activity of the films did not reflect CUR release. A comparison of 2,2-diphenyl-1-picrylhydrazyl (DPPH*) scavenging on the plateau revealed that the CUR-supplemented films had quite comparable antiradical potential. The CMC75/GEL25 system exhibited the highest colorimetric stability, likely as a result of complete encapsulation of CUR in the GEL-rich microspheres. Weak symptoms of physical aging (enthalpy relaxation) were found in the films.

Corn starch and methylcellulose edible films incorporated with fireweed (Chamaenerion angustifolium L.) extract: Comparison of physicochemical and antioxidant properties.

The properties of edible films derived from corn starch (CS) and methylcellulose (MC) supplemented with fireweed extract (FE; 0.0125-0.05% w/w) were analyzed. Due to their more crystalline structure, the MC films were significantly stronger (~26 MPa) than the CS films (~4 MPa). In turn, CS produced films with lower water vapor permeability (WVP, 50.12-51.74 vs. 56.52-59.10 g mm m-2 d-1 kPa-1). The hydrothermally-disrupted starch granules contributed to high roughness and opacity of the CS films. The FE-supplemented films exhibited an intensive yellow color and improved the UV-absorbing effect. FE delayed starch retrogradation, as indicated by the reduced crystallinity and slightly improved transparency of the CS films. Incorporation of FE significantly enhanced the released radical scavenging activity (RSA) of the films, while did not affect the WVP and mechanical properties. Due to better FE-trapping capacity, the CS-based films exhibited lower antioxidant activity (RSA60min = 2.21-19.75%) as compared to the MC counterparts (RSA60min = 4.87-38.31%).

Ascorbic acid- and sodium ascorbate-loaded oxidized potato starch films: Comparative evaluation of physicochemical and antioxidant properties.

The purpose of this study was to compare the effects of increasing concentrations of ascorbate ions (AIs, 0-100mM) in the form of ascorbic acid (AA) and sodium ascorbate (SA) on the properties of edible oxidized potato starch films. The browning reactions were faster in the SA-added films than in those of AA-added. In, turn, AA recrystallized faster than its sodium salt. The highest concentration of SA increased the water vapor permeability of the films. The mechanical strength and stiffness of the films gradually decreased with the increase of AI content. Fourier-transform infrared spectroscopy spectra suggested that addition of SA provoked a more intensive structural changes in the films than AA. X-ray diffraction showed that 25 and 50mM AI-added films exhibited higher crystanility than the control. The films with AA and SA did not differ in terms of dissolving behavior, ability to release AI, and consequently, antioxidant activity.