Effect of concentration calcium chloride crosslinker to pectin based deep eutectic biofilm / Ismahan Zahudin

Biofilm is a flexible film made of biological materials such as polysaccharides that act as a barrier against external elements. The aim of this study is to prepare and characterise biofilm using deep eutectic solvent (DES) as a plasticizer and calcium chloride as a crosslinker. The effect of using different crosslinker concentrations towards the physical and structural properties of pectin-based DES biofilm were investigated. The film manufacturing process was divided into two stages: preparation of deep eutectic solvents and preparation of biofilm. The first stage involved dissolving malonic acid and choline chloride (ChCl:MA) in a mole ratio of 1:1 at 60°C until complete dissolution. The films were prepared using a casting method with pectin and crosslinked by immersing them in CaCl2 solution with varying concentrations (3,5 and 7%). Physical and structural properties include moisture absorption, water solubility and biodegradable test were used to assess the effect of the crosslinking agent. Meanwhile, the interaction of material within films were determined using FTIR-ATR. Results found that, film moisture absorption ranges from 40 to 57.96%, water solubility ranges from 47.23 to 59.04%, and degradation ranges from 1.1 to 9%. This means that the 7% CaCl2 will cause the biofilms to become organized in matrix and resistant to absorption, dissolution, and degradation. As a result, the highest concentration is better suited for biofilm preparation.