Fabrication of cellulose acetate/gelatin-eugenol core-shell structured nanofiber films for active packaging materials.

In this study, novel active materials based on cellulose acetate (CA) and gelatin (Gel) for the release of eugenol (Eg) were developed by fabricating CA/Gel-Eg core-shell structured nanofiber films using the coaxial electrospinning technique. These electrospun nanofibers were coated with a CA shell, which has excellent water stability. Eg was encapsulated on the core part of the Gel. CA/Gel-Eg fiber morphology, structure, thermal, surface wettability, mechanical, encapsulation efficiency, release profile, and biological activity were evaluated. Results showed that the Eg-loaded nanofibers had uniform fiber morphologies and average fiber diameters ranging from 302.5 to 166.6 nm. Eg could be efficiently encapsulated in nanofibers and released for 120 h. Additionally, the CA/Gel-Eg core-shell structured nanofiber films displayed good Eg dose-dependent antibacterial activity. These findings could lead to a new strategy for developing electrospun fibers with a core-shell structure for active food packaging applications.

Impacts of konjac glucomannan with different degree of degradation or deacetylation on the stress resistance and fitness in Caenorhabditis elegans.

The impact of modification in molecules or deacetylation of konjac glucomannan (KGM) on the stress resistance in vivo has rarely been studied systematically. This research studied the effects of KGM with different molecular weights and degrees of deacetylation on the stress resistance and physical fitness of Caenorhabditis elegans. After the nematodes were incubated with modified KGM, the survival rate of nematodes under oxidative and heat stress, as well as the fertility and locomotion were measured. KGM(2-5) with molecular weight of 212, 124, 94 and 67 kDa can significantly prolong the mean and maximum lifespan of nematodes in the presence of paraquat. Under heat stress, all partially degraded konjac glucomannan (PDKGM) showed the significant extension of survival rates. Da(1-3) with deacetylation of 7%, 32% and 46% improved the survival rates of nematodes under oxidative stress. Furthermore, genes expression showed that KGM(2-5) and Da(1-3) upregulated the expression of sod-3, hsp-16.2, and atf-7. Taken together, molecular weight reduction or deacetylation of KGM have a significant impact on the stress resistance in vivo. PDKGM applied in stress resistance will be suggested not to exceed 200 kDa and deacylation of KGM will be suggested to be below 50%.