The effects of clay nanoparticles as reinforcement agent on the properties of starch-protein edible film

In order to minimize the environmental effect, edible film made from starchprotein was introduced which may replace the non-degradable material likes plastic that is commonly used today. As to improve the properties of film, addition of clay is made to the starch-protein film with objective to study the mechanical and physical properties of the starch-protein film. Montmorillonite (MMT) clay was used in this research. For evaluation, the water-vapour permeability (WVP), water solubility and mechanical test (tensile strength and elongation at break) were conducted. From results, the presence of MMT in the film had decreased the value of WVP (3.377×10-9 g/m.s.Pa to 1.0918 ×10- 9 g/m.s.Pa) and percentage of water solubility (98.72% to about 50%). Investigation was conducted for different amount of clay at 5%, 10%, 15% and 20% from weight of starch-protein where some of the results were found inconsistent. Results for mechanical properties showed the decreased in tensile strength with the addition of clay to the starch-protein film. On the other hand, elongation at break improved with clay addition but showed decreasing trend when more clay was added. From analysis, it can be concluded that 5% MMT clay film was the best composition because of the highest elongation at break at 121.5%; significantly higher than others. For tensile strength, WVP and water solubility properties, the 5% MMT clay performances were comparable to others.