Native agar was extracted from cystocarpic, tetrasporic and vegetative
plants of Gracilaria bulsa-pastoris and the agar yield, gel strength,
gelling temperature, intrinsic viscosity and 3,6-anhydro-L-galactose
and sulfate content were analyzed. The results showed no significant d
ifferences in the agar yield and intrinsic viscosities at different re
productive stages. The vegetative plants showed higher gel strength ag
ars than the carposporic and tetrasporic plants, but their gelling tem
perature was lower. The gel strengths and gelling temperatures were ex
plained by the sulfate and 3,6-anhydro-L-galactose contents of the spe
cimens. On the whole, the quality of the agar varied as a function of
the reproductive stages. These results suggest that harvesting should
be avoided during the main period of the reproductive stage of this se
aweed. (C) 1998 Elsevier Science Ltd. All rights reserved.