Extraction of Ulvan from Ulva reticulata and Its Development into Edible Film and Non-Edible Ulvan-Polyhydroxybutyrate (PHB) Composite Film for Environmentally Friendly Bioplastic Applications
Pricilia Amfotis (a), Rukman Hertadi (a*)

Biochemistry and Biomolecular Engineering Research Division, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia
*rhertadi[at]itb.ac.id

Abstract

The increase in conventional plastic waste has driven the search for environmentally friendly bioplastic alternatives. This study aims to extract ulvan from \textit{Ulva} biomass and develop edible film and non-edible ulvan--PHB composite film, along with evaluation of their chemical properties, morphology, and functional performance. Ulvan was extracted using the hot water method (\SI{80}{\celsius}) with varying times of 2--20 hours- the highest yield of \SI{15.85}{\%} was obtained at 12 hours. Edible film was prepared from \SI{3}{\%} (w/v) ulvan with \SI{1}{\%} (w/v) xylitol and \SI{10}{\%} (w/w) citric acid, while non-edible film was prepared from a mixture of ulvan and PHB. FTIR spectra of ulvan revealed characteristic bands of sulfated polysaccharides, supported by H-NMR confirming the ulvan sugar backbone. FTIR of edible film showed dominant O--H, COO-^--, and C--O--C bands, indicating a hydrogen-bonded network, while non-edible film displayed a diagnostic ester C=O band at \SI{\sim 1724}{cm^{-1}} from PHB alongside the ulvan O--H band, confirming composite formation. All samples were characterized using SEM, FTIR, and evaluated for biodegradability, antibacterial activity, and solubility. Overall, ulvan with an optimal yield at 12 hours, along with the utilization of extraction residue for PHB production, demonstrates an integrated \textit{Ulva} biomass-based approach for producing film materials with potential sustainable packaging applications.

Keywords: bioplastics, ulvan, polyhydroxybutyrate, film characterization, food packaging

Topic: Biochemistry