Preparation and Characterization of Film Based on Cellulose Acetate with Longan Seed Extract

Longan seeds contain high amounts of polyphenols, which have been shown to have high antioxidant and antibacterial activities but are not effectively utilized. The utilization of longan seed extract (LSE) not only taps into readily available and abundant raw materials, addressing economic concerns, but also enhances the quality of food packaging films based on cellulose. In this study, the longan seed extract (LSE) was extracted from longan (Dimocarpus longan) seeds using three common solvents (ethanol, mixed ethanol-water 1:1 v/v, and water solvent). The extracted polyphenol content in the LSE with the ethanol-water solvent 1:1 of 179 mg<middle dot>g- 1 was the highest compared to the other solvents. The obtained extract exhibited the ability to scavenge free radicals (DPPH) with an IC50 of 65.30 (mu g<middle dot>mL- 1) and demonstrated antibacterial properties against E. coli and S. aureus. The films based on cellulose acetate (CA) with LSE (denoted as CA/LSE film) in varying volume CA/LSE ratios (10/0, 10/1, 10/1.5, and 10/2) were firstly manufactured using a solvent casting method with the extracted solution. SEM micrographs of the samples showed uniformity in the CA/LSE sample structure, improving the tensile strength of the initial polymer film, increasing from 38.9 MPa to 43.5 MPa. However, the elongation at break of the samples slightly decreased. The CA/LSE films demonstrated the potential to meet the requirements of antimicrobial food preservation films, emphasizing their environmentally friendly nature. The extract from longan seed (LSE) has a polyphenols content of 179 mg<middle dot>g-1.The films of cellulose acetate and LSE were formed using the casting method.Adding LSE improved the tensile strength and antibacterial activity of the film.