Secalin films acylated with capric acid chloride
Secalin was chemically modified using the acylation reaction with the aim to prepare less hydrophilic protein- based films with features suitable for applications in food packaging. The acylation of secalin was done at different capric acid chloride concentrations (2–6 mmol/g) and confirmed using elementary and Fourier- transform infrared spectroscopy analyses. The water sensitivity of the films prepared with acylated secalin was observed to be significantly improved. The control film elongation at break was ~67% and increased up to 141% at high levels of acylation, whereas tensile strength and Young’s modulus increased up to 4.5 and 39.4 MPa, respectively when lower amounts of capric acid chloride were used and, on the other hand, decreased with increasing amounts. Thermal analyses suggested that the glass transition temperature of acylated films was lower at higher capric acid chloride concentrations, whereas the melting temperature increased and the thermal stability improved. Scanning electron microscopy showed a more homogeneous surface of the films obtained with acylated secalin.