Characteristics of Alginate Extract from Padina Sp.

Abstract

Alginate is a complex organic compound of phycocolloid, extracted from brown seaweeds.   The objective of this research was to obtain the best extraction procedure and to evaluate the characteristics of alginate produced from Padina sp.This research used a Block Random Design having two phases. The first phase had two factors, i.e HCl solution (0,5, 0,75, and 1%) and  concentrations of Na2CO3 (2,5 5 and 7,5%). The best result of the combinations was used for the second research. The second phase also had two factors, they were Ca(OCl)2 as bleaching agent (0, 1 and 2%) and  concentration of purification agent by using isopropanol (75, 85 and 95%). As the second  parameters taken were yield, water content, ash, lightness, Pb and Hg content, viscosity and  effect of pH and heating on the product.The result showed that there was a significant interaction of HCl and Na2CO3 concentration ( = 0,05) to the yield. But insignificant result were the viscosity and ash content. The concentration of HCl showed a significant effect to ash content. There was an interaction between HCl concentration  and Na2CO3 to the yield, water content and viscosity. The concentration of Ca(OCl) 2 and isopropanol showed a significant effect to viscosity and water content, and showed an insignificant effect to lightness. The best treatment was the combination between HCl  1% and Na2CO3 5%,  bleached by using Ca(OCl)2 2%  and purified by using  isopronanol 85%. They produced 30,30% of alginate salt, having parameters such as: viscosity of 12,2 cps, ash content of 30,51%, water content of 11,21% and lightness score of 53,89.The characteristics alginate produced from Padina sp. revealed having Hg content of  0,26 ppm and 6,15 ppm of Pb which is still below the limit of government regulation, and  posess  of decreasing of viscosity on extreme pH as well as heating treatments.  By using infra red spectrum,  the  alginate  produced  in this experiment  characterized into a  Chemical group of C-C-C-C-C-C,  -O-H. –COOH,C-O-C, and C-H.

Key words : alginate, extraction,  characterization