Lipase-mediated bi-phasic modification of citrus pectin (MCP) and expedition of its packaging film characteristics

This study focuses on the enzymatic modification of citrus pectin (CP) with stearic acid (SA) in a bi-phasic reaction system, with the aim of enhancing its application in packaging films. We employed a central composite design of experiments and principal component analysis to investigate the effects of pH, reaction temperature, and time on the modification process. The principal component analysis identified reaction time and temperature as critical factors influencing modification, leading to a maximum modification percentage of 43.35 ± 1.81 % at pH 7, 60 °C, and 72 h. The physical characteristics of modified citrus pectin (MCP) showed increased molecular weight and particle size, thereby influencing the packaging films' mechanical and barrier properties. Zeta potential measurements indicated improved dispersion stability, resulting in homogeneous film formation. Chemical analyses confirmed the structural modifications in MCP. The characterisation of MCP-based films revealed a trade-off between properties: a significant reduction in mechanical strength was observed, offset by substantial improvements in water and oxygen barrier performance. This work positions MCP as a functional biopolymer for developing advanced composite packaging materials with tailored barrier properties.