Seasonal agar yield and quality in Gelidium canariensis (Grunow) Seasone-Camba (Gelidiales,Rhodophyta) from Gran Canaria, Spain

Abstract

The seasona! effects on yield and gél properties of Gelidium canariensis agar were investigated at two intertidal popu!ations at the northern coast of Gran Canaría. Physlcal and rheological properties were measured in 1.5% w/v so!utions after treatment with alkali. No significant differences were found on agar characteristics between the two sites studied. Two highest yields were obtained during summer with a maximum in June (27.8%) and mínimum during late autumn and winter (18-18.6%). Overall quality was highest in winter (November-January). when gel strength peaked above 850 g cm2• The results showed an agar of industrial quality.