Impact of fish myofibrillar protein and apple pectin–konjac glucomannan on the physical, thermal, and micro-structural properties of biodegradable blend film

Abstract The present study aims to develop a biodegradable film using apple pectin (AP), konjac glucomannan (KG), and different concentrations (1%–4% w/v) of fish myofibrillar protein (FMP). The results revealed a concomitant increase in thickness with FMP levels in apple pectin–konjac glucomannan film-forming solution and a reduced visible and UV light transmittance to below 60%. Disappearance of myosin heavy chain bands was noticed in FMP-added films. The different wavenumbers of Fourier transform infra red spectra suggest the interaction ofprotein and polysaccharide components. The third endothermic peaks represent cross-links of polysaccharide and protein chains. The residual weights at the end of the second stage without FMP were 37.51% and with FMP ranged between 47% and 72%, respectively, suggesting lower mass loss and increased thermal stability. Scanning electron miscroscopy images indicated a decline in surface homogeneity with FMP content. The biodegradable films with enhanced light/UV barrier properties and thermal properties can be prepared utilising optimised levels of FMP.