Agar polysaccharides from Gracilaria species (Rhodophyta, gracilariaceae)

Yield, physical and chemical properties of agar from three agarophytes species (Gracilaria gracilis, G. dura and G. bursa pastoris) were determined. The agar yield from the three species varied significantly (P < 0.01). The highest yields of agar (34.8%) and the lowest (30%) were obtained from G. bursa pastoris and G. gracilis, respectively. Highest gel strength (630 +/- 15 g cm(-2)) was obtained from agar extracted from G. gracilis and lowest from G. bursa pastoris (26 +/- 3.6 g cm(-2)). The values of 3,6-anhydrogalactose were similar for G. gracilis and G. dura and there were no significant differences among the species. The sulfate contents varied significantly (P < 0.01) and the higher value was obtained from G. bursa pastoris. Among the three species, G. gracilis showed superior agar quality than the other two species, hence it can be considered a good potential source for industrial use. (C) 2001 Elsevier Science B.V. All rights reserved.