The effect of glycerol and sago starch addition on the characteristics of bioplastic based on orange peel pectin

Abstract

Sustainable food packaging materials have significant interest in addressing environmental issues by making renewable substitutes such as bioplastic based on pectin. Orange peel has a relatively high pectin content of 42.5%, which can be synthesized into bioplastic. Pectin-based bioplastic tend to have limitations in terms of mechanical and physical strength due to the hygroscopic nature of pectin. This study aims to determine the effect of adding glycerol and sago starch on the characteristics of orange peel pectin-based bioplastic. The casting method was used in the bioplasctic formulation using the variation of the pectin:starch ratio (75:25, 65:35, 55:45; and 50:50%) and glycerol composition (10, 20, 30, and 40%). Based on the results, the pectin obtained categorized as low methoxyl pectin and ester pectin. The characterizations of bioplastic achieved the maximum value of the tensile strength of bioplastic was 4.22 MPa, obtained by adding pectin:starch (50:50%) and 10% glycerol. The maximum value of the elongation properties at the break of bioplastic is 24%, obtained by adding the composition of pectin:starch (75:25%) and 40% glycerol. The more additions of the pectin:starch and glycerol composition result in higher water vapor evaporation rate. Hence, utilizing orange peel pectin-based bioplastic offers a sustainable solution by exploring repurposing waste to create bioplastic for food packaging, thereby contributing to environmental preservation.