Characteristics of lipid content from the analysis of structural and optical properties of brown seaweed (Sargassum polycystum) after defatting by petroleum ether: preliminary studies

Abstract

In Indonesia, one species of brown seaweed is Sargassum polycystum, which has not been optimally utilized. Whereas their wide range of potentiality, especially their bioactive compounds. Several authors have reported that the chemical composition of seaweeds varies according to maturity, habitats, environmental conditions, treatment, and species. This work describes the structural and optical properties of Sargassum polycystum after treatment by petroleum ether to remove lipid content. The structural properties determined from the quantitative analysis of XRD spectra. The chemical bond and optical properties determined from the quantitative analysis of FTIR Spectra by applying Kramers-Kronig relation. The data XRD showed an increasing the average of the crystallite size from (23.92 nm Scherrer method; 14.35 nm Williamson-Hall method; 19.23 nm Size strain plot method) to (32.39 nm Scherrer method; 20.07 nm Williamson-Hall method; 28.06 nm method) after treatment. The analysis of FTIR showed COC, CCH, CH, and OH bonding.