Eco-Friendly Laccase/Lauryl Gallate/Chitosan Enzymatic Pretreatment of Cellulose in Enhancing Moulded Pulp Product Properties

In this study, the effectiveness of enzymatic treatments on cellulose for improving the properties of moulded pulp products was investigated. Three treatment systems were evaluated: laccase (L) alone, an L/lauryl gallate (LG) binary system, and a L/LG/chitosan (CTS) ternary system. The optimal conditions for the L/LG/CTS system were determined as 40.0 U·g −1 L, 1.0 wt.% LG, 1.0 wt.% CTS, 3.0 wt.% pulp consistency, a reaction temperature of 50°C, and a reaction time of 4 h. Compared with untreated moulded pulp products, which exhibited poor barrier properties (static water contact angle: 0°, Cobb 60 : 141.21 ± 5.24 g·m −2 , Kit test: 0/12) and limited mechanical performance (tightness: 1.04 ± 0.03 g·cm −3 , tensile index: 29.86 ± 1.32 N·m·g −1 , bursting index: 0.85 ± 0.07 kPa·m 2 ·g −1 , tear index: 5.72 ± 0.28 mN·m 2 ·g −1 , folding resistance: 82 ± 2), the L/LG/CTS-treated products demonstrated notable improvements. Specifically, hydrophobic/oleophobic properties improved markedly (static water contact angle: 104.5° ± 2.9°, Cobb 60 : 14.83 ± 0.71 g·m −2 , Kit test: 8/12) and mechanical strength increased substantially (tightness: 1.18 ± 0.03 g·cm −3 , tensile index: 34.78 ± 0.96 N·m·g −1 , bursting index: 1.88 ± 0.09 kPa·m 2 ·g −1 , tear index: 6.23 ± 0.30 mN·m 2 ·g −1 , folding resistance: 93 ± 5). SEM analysis revealed changes in fibre arrangement and improved fibre network cohesion in treated samples. These findings indicate that the L/LG/CTS ternary system is a highly effective and sustainable strategy for enhancing both barrier and mechanical properties of moulded pulp products, positioning them as a promising alternative to petroleum-based plastics for food packaging applications. Although the L/LG/CTS system uses biodegradable components, future investigations are required to comprehensively evaluate the biodegradability of the final treated products.