Seasonal variations in yield and quality of agar in Brittany's seaweeds
Briand, X. (1989). Seasonal variations in yield and quality of agar in Brittany's seaweeds, in: De Pauw, N. et al. (Ed.) Aquaculture: a biotechnology in progress: volume 1. pp. 431-438 In: De Pauw, N. et al. (1989). Aquaculture: a biotechnology in progress: volume 1. European Aquaculture Society: Bredene. ISBN 90-71625-03-6. 1-592 pp., more |
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Abstract | In 1981, an estimated 144t of agar were used in France mainly in the pharmaceutical industry (21%), the production of culture media (24%), and the food industry (55%). Presently only 55% of the current needs are being met by the production. Before undertaking the actual farming of agarophytes, the yield variations in dry matter and agar, and the quality of six species of natural red seaweeds were studied over a period of 1yr. The species examined were: Gracilaria verrucosa (Hudson) Papenfuss (Gv), Gracilaria foliifera (Forskal) Boergesen (Gf), Graciliaria compressa(C. Agardh)Greville (Gc), Gelidium latifolium(Greville) Thuretet Bornet(GI), Gelidium pulchellum (Turner) tzing (Gp), and Ahnfeltia plicata(Hudson) Fries (Ap). The highest agar yields were obtained with Gp (40%) and GI (35%), and the highest gel strengths with Gp (685g.cm-2), and GI (659g.cm-2). Seasonal variations in gel yield and quality were more or less pronounced, depending on seaweed species. The maximal agar yield was found during the summer months for GI, Gv, Gf, and Ap. The best gel strengths are generally obtained between late summer and early autumn. Ranking based on the yields of dry matter and agar obtained, as well as on colloidal quality , seems to be as follows. GpGIGfApGvGc. Gp and GI produce bacteriological agars and Ap and Gf agars for food products. Gv and Gc are of no interest at the present time. On the basis of the present results it can be concluded that Gelidium latifolium and Gelidium pulchellum are the most interesting agarophytic species to be farmed on Brittany's coasts. |
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