PRODUCTION AND CHARACTERIZATION OF BIO-PLASTIC FROM BY-PRODUCT OF AVOCADO SEED STARCH FOR FOOD PACKAGING MATERIALS

Abstract

Avocado seed starch, a plentiful byproduct of agro-industrial processes, presents considerable promise as a sustainable and biodegradable resource for the creation of bioplastics. With its substantial starch content and ability to form films, it serves as a viable substitute for traditional petroleum-derived plastics, especially in the realm of food packaging.  In this study, starch extracted from avocado seeds was utilized to produce bioplastic films, reinforced with microcrystalline cellulose (MCC) derived from Ensete ventricosum fibers. Environmentally friendly processing methods, including aqueous extraction, alkaline treatment, and mechanical dispersion, were employed. Glycerol was incorporated as a plasticizer to enhance film flexibility. Bioplastic films were prepared by solution casting, using glycerol as a plasticizer and varying MCC content (0%, 1%, and 5% by weight). Characterization techniques included tensile strength testing, FTIR spectroscopy, thermal gravimetric analysis (TGA), water retention value (WRV) tests, and UV–Vis spectroscopy. Experimental results showed that MCC significantly enhanced the film’s mechanical properties. At 5% MCC loading, tensile strength increased from 714 Pa (pure starch film) to 12.8 MPa, satisfying the minimum requirement for plastic packaging applications (≥10 MPa). Elongation at break improved from 3.25% to 6.52%, and film thickness slightly decreased from 0.847 mm to 0.830 mm, indicating better compactness and structural integrity. FTIR analysis confirmed strong hydrogen bonding between starch and MCC, while thermal and WRV analysis demonstrated improved thermal stability and reduced water absorption. UV–Vis results revealed reduced transparency due to cellulose incorporation, enhancing UV-blocking performance. Future work should investigate optimizing cellulose loading levels, especially beyond 5 wt%, to further improve performance metrics such as tensile strength, moisture barrier properties, and shelf-life protection.