Sustainable biopolymeric films of gelatin/kappa-carrageenan reinforced with jackfruit-derived cellulose nanocrystals for mushroom packaging

Abstract

In this research, cellulose nanocrystals were derived from jackfruit peel (JCNCs) through the acid hydrolysis method and analysed using TEM, SEM-EDS, DLS and XRD techniques. The mean size of prepared spherical cellulose nanocrystals was 97.56 nm. These characterised JCNCs were then integrated into a gelatin/kappa-carrageenan (GK) matrix at increasing concentrations to fabricate biopolymer films labelled as GKC-1, GKC-2, GKC-3 and GKC-4. The prepared films were extensively characterized, including assessments of UV-blocking capability, transparency, mechanical strength, FTIR, XRD analyses, water vapor permeability (WVP), oxygen permeability (OP), water solubility (WS), moisture retention capacity (MRC), SEM-EDS imaging, soil burial biodegradability testing and antioxidant activity. The addition of JCNCs notably modified the structural and functional attributes of the GK films. The optimized GKC-4 film exhibited enhanced performance in several critical areas compared to the control film (GK), such as a 30.5% reduction in WVP, an 87% increase in tensile strength, a 182.264% and 151.447% rise in DPPH and ABTS antioxidant activities and a 39.19% decrease in the degradation rate during the soil burial test. Furthermore, packaging experiments were conducted with button mushrooms stored at 4 °C for 12 days. The findings indicated that the GKC-4 film significantly minimized weight loss to 9.21 ± 0.02% and retained pH stability at a 6.61 ± 0.15 pH value compared to unpackaged samples and commercial polyethene films. These results highlight the potential of JCNC-reinforced biopolymer films as sustainable and functional alternatives for active food packaging.