AGAR FROM THE REPRODUCTIVE AND VEGETATIVE STAGES OF GRACILARIA BURSA-PASTORIS

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.