New gel from a water-soluble Carboxymethyl chitosan-Cinnamaldehyde Schiff base derivative as an effective preservative against soft rot in ginger

Ginger, valued for its culinary and medicinal properties, suffers substantial production loss—up to 90 %—due to fungal soft rot. To combat this, we have developed an environmentally sustainable antifungal polysaccharide gel derived from a water-soluble Schiff base of O-carboxymethyl chitosan (CMC) and cinnamaldehyde (CIN). Terpene incorporation was confirmed via various characterization techniques, including Fourier transform infrared (FT-IR), pH-dependent release, solubility, thermogravimetric analysis, and UV–vis spectra. Results showed successful grafting of CIN onto the polysaccharide, at a CIN:CMC ratio of 120 mg/g. In vitro evaluation demonstrated significant antifungal activity against F. oxysporum, with a MIC value of 159.25 μg/mL. Application of the CMC=CIN gel to ginger rhizomes inhibited spore germination in all evaluated wounds, enhancing gloss and appearance. These findings validate the efficacy of this novel, environmentally friendly gel in preventing ginger loss caused by fungal infections. [Display omitted] •A new water soluble Carboxymethyl chitosan-cinnamaldehyde gel (CMC=CIN) were obtained.•Successful grafting of CIN onto polysaccharide was obtained, with a ratio of 120 mg/g.•New gel displayed higher antifungal activity with a minimum MIC of 159.25 μg/mL.•Gel on ginger rhizomes inhibited spore germination, enhancing the appearance.