Traditional petroleum-based food-packaging materials have poor permeability, limited active packaging properties, and difficulty in biodegradation, limiting their application. We developed a carboxymethylated tamarind seed polysaccharide composite film incorporated with epsilon-polylysine (CTP epsilon) for better application in fresh-cut agricultural products. The CTP epsilon films exhibit excellent water vapor barrier properties, but the mechanical properties are slightly reduced. Fourier transform infrared spectroscopy and X-ray diffraction spectra indicate the formation of hydrogen bonds between epsilon-PL and CTP, leading to their internal reorganization and dense network structure. With the increase of epsilon-PL concentration, composite films showed notable inhibition of postharvest pathogenic fungi and bacteria, a significant enhancement of 2,2 '- azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical-scavenging activity, and gradual improvement of wettability performance. Cytotoxicity experiments confirmed the favorable biocompatibility when epsilon-PL was added at 0.3% (CTP epsilon(2)). In fresh-cut bell pepper preservation experiments, the CTP epsilon(2) coating effectively delayed weight loss and malondialdehyde increase preserved the hardness, color, and nutrients of fresh-cut peppers and prolonged the shelf life of the fresh-cut peppers, as compared with the control group. Therefore, CTP epsilon composite films are expected to be a valuable packaging material for extending the shelf life of freshly cut agricultural products.
