Citric acid cross-linked curcumin/chitosan/chickpea flour film: An active packaging for chicken breast storage

Since there has been an increasing interest in natural, non-toxic, and biodegradable food packages instead of plastic ones, scientists put great effort into eliminating the potential drawbacks of these biodegradable films. In this study, citric acid (CA) was utilized as a crosslinker for the films produced by chitosan (CS), chickpea flour (CF), and active agent curcumin (CUR) by a solvent casting technique. CA was introduced into the film formulations at different concentrations (0, 0.5%, 1%, 1.5% w/v), and the influence on the functional film characteristics were extensively analyzed. Increasing CA concentration in formulation caused a reduction in water vapor permeability (WVP) of the films such that the film with the highest CA concentration (1.5-CUR/CF/CS) was 62.6% more resistant to water vapor than film without CA (0-CUR/CF/CS). When CA concentration in the film formulation was increased, elongation at break (EAB) value increased from 1.64% ± 0.13%, to 11.1%± 1.21% whereas tensile strength (TS) value decreased from 7.83± 0.08 MPa to 3.58± 0.20 MPa. Contrary to expectations, antioxidant activity of the films decreased with increasing CA concentration. X-Ray Diffraction (XRD) patterns of the films proved the amorphous nature and inhibitory characteristic of CA against retrogradation. In addition to all these, CA concentration significantly influenced Thermogravimetric analysis (TGA) pattern of the films with the increasing number of degradation stages. Besides the cross-linker characteristic of CA, it also extensively enhanced the antibacterial characteristic of the films. Films formulated with 1.5% (w/v) CA (1.5-CUR/CF/CS) showed antibacterial effect against both Escherichia coli (E.coli) (ATCC 11229) and Staphylococcus aureus (S.aureus) (ATCC 43300). Finally, chicken breast packed with 1.5-CUR/CF/CS films remained below unacceptable microbial threshold limits even at the end of the 9th -day of storage compared to samples packaged with the film with no antibacterial activity. [Display omitted] •Citric acid cross-linked chitosan, chickpea flour, and curcumin composite film were developed.•Citric acid incorporation changed permeability, mechanical and thermal properties significantly.•Antioxidant activity of the film decreased with increasing citric acid concentration.•Films with the highest citric acid showed antimicrobial activity against both S.aureus and E.coli.•Chicken breast packed with 1.5-CUR/CF/CS was still acceptable at the end of the 9-day st