PROSES EKSTRAKSI KARAGENAN DARI Eucheuma cottonii

Abstract

Kappa carrageenan extraction process was developed for Eucheuma cottonii by investigating the effects of water and KOH solution (concentration 0.1, 0.2, and 0,3N) as the solvent on carrageenan yield and gel properties. Extraction process was carried out with a constant ratio of seaweed weight to solvent volume ( 1: 30; g/mL) at 100oC in water bath equipped by shaker and at different time until the equilibrium was attained (60 minutes). The extract was then precipitated in 3 volume of 90% ethanol, oven dried at 60oC until constant weight. Based on experimental data, pure water was the most efficient solvent with regard to yield but certainly not gel strength. Alkali significantly influenced carrageenan yield and properties. Increasing the KOH concentration leads to carrageenan containing less sulfate content. The gel strength was improved as the increasing KOH concentration. Also, the sulfate content decreased with the increasing extraction time. The extraction product was found to have virtually identical FTIR spectra to the reference samples of kappa-carrageenan.