Development of bio-based cooking oil-absorbing paper from rice straw fiber, kaffir lime (Citrus hystrix DC) fiber, and cassava starch (Cultivar 81)

This study focused on the development of oil-absorbing paper from bio-based materials using rice straw fiber (RF), kaffir lime fiber (KF), and cassava starch (Cultivar 81) as the main components. The effects of KF incorporation at different proportions (0, 10, 30 and 50% by weight of rice straw) were investigated to evaluate the chemical, physical, mechanical, antimicrobial, and biodegradability properties. All samples were analyzed using FTIR spectroscopy to examine their chemical structures. The results showed a noticeable decrease in signals corresponding to hemicellulose and lignin after alkaline treatment, while the cellulose structure remained evident. Based on the analysis of physical and mechanical properties and oil-absorbing performance, the sample containing 30% KF exhibited the most balanced and optimal performance. This sample showed enhanced oil absorption, high porosity, suitable thickness, and a fibrous structure that facilitated efficient oil uptake, making it particularly suitable for food applications. Furthermore, the inclusion of KF effectively inhibited the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with the inhibition zone diameter increasing proportionally with KF content. However, a higher KF content slightly reduced the biodegradation rate, likely due to its antimicrobial properties that suppressed microbial activity in the soil. Overall, incorporating KF into rice straw-based paper significantly improved its oil absorption capacity, mechanical and hydrophobic properties, and antimicrobial activity, without compromising biodegradability. These characteristics highlight its promise as an environmentally sustainable material for oil-absorbing and packaging applications.