Hydrophobic edible composite packaging membrane based on low-methoxyl pectin/chitosan: Effects of lotus leaf cutin

Abstract

In this study, cutin extracted from lotus leaf was incorporated with low-methoxy pectin and chitosan to prepare hydrophobic edible composite membranes. Results showed that the formation and microstructure of the membranes were affected by the addition of lotus leaf cutin, which filled the gap between chitosan and low-methoxyl pectin. This addition results in obvious changes in the composite packaging membranes and weakens crystal peaks. According to the contact angle measurement, the hydrophobicity of composite packaging membranes was enhanced by the addition of lotus leaf cutin increasing the contact angle from 61.8° to 90.3°. With the increased cutin addition from 0 g to 3 g, water absorption was significantly decreased from 48.83 % to 41.64 %, whilst water vapour permeability increased from 12.91 g/cm2·d to 16.18 g/cm2·d. Simultaneously, the tensile strength and fracture elongation were improved from 5.43 MPa and 95.6 % to 5.96 MPa and 128 %. The thermal stability of composite packaging membranes was also enhanced by the incorporation of lotus leaf cutin.