Agar polysaccharides from Gracilaria species (Rhodophyta, gracilariaceae)

Yield, physical and chemical properties of agar from three agarophytes spec ies (Gracilaria gracilis, G. dura and G. bursa pastoris) were determined. T he agar yield from the three species varied significantly (P < 0.01). The h ighest yields of agar (34.8%) and the lowest (30%) were obtained from G. bu rsa pastoris and G. gracilis, respectively. Highest gel strength (630 +/- 1 5 g cm(-2)) was obtained from agar extracted from G. gracilis and lowest fr om G. bursa pastoris (26 +/- 3.6 g cm(-2)). The values of 3,6-anhydrogalact ose 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 th e three species, G. gracilis showed superior agar quality than the other tw o species, hence it can be considered a good potential source for industria l use. (C) 2001 Elsevier Science B.V. All rights reserved.