Preparation, physicochemical and biological evaluation of quercetin based chitosan-gelatin film for food packaging.

Ecofriendly chitosan-gelatin (Ch-ge) bio-composite films containing Quercetin-starch (Q) were synthesized using solution casting method. Physicochemical characteristics and mechanical properties of the resulting chitosan-gelatin containing Quercetin-starch films (Ch-ge-Q) were studied using UV, FTIR, XRD and SEM techniques. The films were also investigated for their swelling, water-vapor permeability (WVP), water solubility properties. The FTIR spectra confirmed the chemical interactions between the chitosan-gelatin and Q. Surface morphology of prepared film was analyzed by the SEM imaging while XRD spectra suggest the expanded crystallinity of the film with the addition of Q. The film also showed enhanced barrier property against UV rays. The reduction of water-vapor permeability and increase in tensile strength while a decrease in elongation at break has been observed in the Ch-ge-Q film compared to Ch-ge film. The antibacterial activity of Ch-ge-Q film against both gram positive (B. substilis) and gram negative (E. coli) bacteria suggested the Q loaded Ch-ge films as more feasible antibacterial candidate especially against the strain E. coli. The antioxidant activity of the Ch-ge-Q film was evaluated using the DPPH and ABTS as standards and corresponded to 81.45% of DPPH and 72.2% of ABTS scavenging activities. It was observed that the film containing Quercetin-starch presented superior antioxidant activity results in comparison to Ch-ge film promising its application in food packaging.

Cu(II)-carboxymethyl chitosan-silane schiff base complex grafted on nano silica: Structural evolution, antibacterial performance and dye degradation ability.

O-Carboxymethyl chitosan (OCMC) Schiff's base was utilized for a new class of organic-inorganic hybrid material by grafting it on nano-silica-silane and further metallated with Cu (II). Here (3-Aminopropyl) triethoxysilane (APTES) was used as a linker and 2-hydroxy-1-naphthaldehyde (HN) for Schiff's base formation. The hybrid was characterized by FTIR, TGA, powder XRD, SEM, CHN, DLS, ICP-AES, diffuse reflectance UV-vis and EDX spectroscopic techniques. Magnetization measurements were carried out by VSM at room temperature. This study explored the possible synergic effect of unique properties of carboxymethyl chitosan, Schiff's base Cu (II) complex and nano-silica towards antibacterial activity and in dye degradation studies. The antibacterial performance of nano-hybrid material was examined against both Gram-positive (Escherichia coli) and Gram-negative (Bacillus subtilis) bacteria. The catalytic activity of the hybrid was tested for degradation of reactive black 5 (RB5) through advanced oxidation processes using H2O2 as oxidant. The results show a high dye degradation efficiency of 93% in 130min by the hybrid catalyst with reusability. As per published reports, Chitosan-Schiff's bases show strong antimicrobial activity and their Cu complexes exhibit good catalytic and anticancer activities. Therefore, it is expected that the new organic-inorganic hybrid would be highly applicable in environmental as well as biomedical fields.