Optimization of physical, mechanical and thermal properties of myofibrillar protein–cellulose nanocrystal nanocomposite

Nanocrystalline cellulose (NCC) reinforced fish myofibrillar protein (FMP)-based nanocomposite film was prepared by solution casting. The NCC content in the matrix was varied from 2, 4 and 6% ((w/w) % dry matrix). It was found that the nanocomposite reinforced with 6 wt% NCC content exhibits the highest tensile strength which was increased by 49% compared to the control. The formation of percolated networks of cellulose nanocrystals within protein matrix resulted in improving the mechanical properties of nanocomposites. Incorporation of NCC also significantly improved water vapor permeability (WVP) of the nanocomposite showing a 33% decrease due to 6 wt% NCC loading. The moisture sorption and water solubility studies revealed that the addition of cellulose nanocrystals reduced the moisture affinity of FMP, which is very favorable for edible packaging applications. Molecular interactions between FMP and NCC were supported by Fourier Transform Infrared Spectroscopy. Investigation of DSC factors (Tg, Tc, Tm) shown that thermal stability of FMP-based nanocomposite films was improved after incorporation of NCC.