PENGARUH KONDISI PROSES PADA PENGOLAHAN EUCHEUMA COTTONII TERHADAP RENDEMEN DAN SIFAT GEL KARAGENAN

Since natural carrageenan are mixtures of different sulfated polysaccharides, their composition differs from batch to bacth. Chemical used in seaweed processing effects on yield and gelling properties of carrageenan from Eucheuma cottonii seaweed, largely sourced from Indonesia. The properties differ from batch to batch. Therefore, the quantitative analysis of carrageenan batches is important. The carrageenan was prepared by alkaline extraction, followed by alcohol precipitation. The effect of extracting alkali concentration ( NaOH 0.05 – 0.2N and KOH 0.13 – 0.36N), alcohol concentration (ethanol 70 – 90% v), and bleaching treatment of seaweed ( bleached and unbleached seaweed ) on yield and gelling properties were investigated. The higher yield could be reached in KOH solvent and concentrated alcohol. The higher alkali concentration enhanced carrageenan gel strength and melting and gelling temperature. Besides, bleaching seaweed reduced both the yield and gelling properties. Keywords: carrageenan, alkaline extraction, alcohol precipitation, gelling properties