Development of biodegradable films based on seaweed polysaccharides and Gac pulp (Momordica cochinchinensis), the waste generated from Gac oil production

Gac (Momordica cochinchinensis) is a tropical fruit. It belongs to the Cucurbitaceae family. Gac pulp (or mesocarp) that accounts for 40-50% of fruit weight is commonly discarded during the processing of Gac fruit. However, this by-product is a rich source of nutrients and bioactive compounds, which are potential to produce edible films. This study aimed to determine the effect of sodium alginate, kappa-carrageenan, Gac pulp and glycerol on film properties and optimise the formula of this composite film for further applications using a response surface methodology (RSM). The results showed that sodium alginate, kappa-carrageenan, Gac pulp, and glycerol affected physical and barrier properties, colour parameters, and mechanical properties of the films. The optimal formulation to generate a composite film from Gac pulp include sodium alginate 1.03%, kappa-carrageenan 0.65%, Gac pulp 0.4%, and glycerol 0.85% (w/v), where this film produces high mechanical properties, low water vapour permeability and acceptable physical properties. This optimised film formulation demonstrates a potential for food application.