Development and application of rice starch-based edible food packaging : incorporating hydrophilic and hydrophobic plasticizers / Muhammad ‘Atiq bin Juani @ Najrienbin Juani

Submitted in fulfillment of the requirements for the degree of Master of Science (by Research)

ABSTRACT This study aims to develop rice starch-based edible food packaging films by incorporating hydrophilic (glycerol) and hydrophobic (coconut oil, palm oil, sesame seed oil, sunflower oil, and beeswax plasticizers to enhance their functional properties. The hypothesis is that different plasticizers will significantly influence the films' physical, mechanical, barrier. antioxidant, cytotoxicity, and biodegradability properties. Rice starch-based biofilms were developed using these plasticizers through a solution-casting method. Physical properties like thickness remained consistent, ranging from 0.221 mm to 0.268 mm. The incorporation of coconut oil resulted in higher opacity due to increased saturated fatty acid content. Light microscopy revealed irregularly shaped rice starch granules, dispersed oil droplets, and granular structures with beeswax. Mechanical properties varied, with coconut oil improving elongation at break and sunflower oil increasing the modulus of elasticity. Sesame seed oil showed lower solubility and water swelling due to weaker interactions with starch. Fourier-transform infrared analysis indicated hydrogen bond formation between starch and plasticizers. Beeswax demonstrated the highest antioxidant activity. The films exhibited negligible toxicity in the brine shrimp lethality assay, indicating potential biocompatibility.
However, the presence of plasticizers may hinder biodegradation, with coconut oil films degrading slower due to higher saturated fatty acids. Overall, the films degraded rapidly in soil and compost, showing promise as eco-friendly materials. In practical applications, the films with coconut oil exhibited enhanced inhibition of total plate count, yeast, and molds during 7 days of storage at both refrigerated and room temperature conditions. Decreased pH during peanut storage was attributed to natural biochemical processes and microbial activities producing organic acids. Beeswax minimized weight loss by reducing moisture evaporation.
These findings suggest that coconut oil and beeswax can enhance food safety and preservation, making them suitable components in biodegradable food packaging materials and addressing food spoilage and waste challenges. Additionally, incorporating specific hydrophilic and hydrophobic plasticizers into rice starch-based films can significantly enhance their functional properties, making them a viable alternative to conventional plastic packaging. Future research could explore the optimization of these formulations and investigate the use of local rice strains for broader applications in sustainable packaging solutions.

Dissertation (Degree of Master of Science by Researcher) - University Teknologi Brunei - 2023

Includes references pages 99-109