title: SEASONAL VARIABILITY OF PHYSICOCHEMICAL AND RHEOLOGICAL PROPERTIES OF ULVAN IN TWO ULVA SPECIES (CHLOROPHYTA) FROM THE BRITTANY COAST(1).
abstract: The seasonal variability in the extraction yield, physicochemical characteristics, and rheological properties of ulvan from two Ulva species contributing to Brittany "green tides" has been studied. These seaweeds were collected in the water column for Ulva armoricana Dion, de Reviers et Coat and on hard substrata for Ulva rotundata Bliding. The maximum ulvan extraction efficiency was not related to the maximum ulvan content in the seaweeds, but with the active growth period of the seaweeds. Ulvan chemical structure, macromolecular characteristics, and rheological properties were affected by both species and seasons. The proportion of high-molecular-weight ulvan was the major factor positively correlated with the gelling properties. Characteristics of ulvan from U. rotundata subjected to tides were more affected by seasons than ulvan from U. armoricana living in a more constant environment. These results point to several useful recommendations concerning Ulva sp. biomass collected with regard to ulvan characteristics and uses.
authors.affiliation: Centre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, France Institut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, FranceCentre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, FranceInstitut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Robic
authors.affiliation: Centre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, France Institut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, FranceCentre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, FranceInstitut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Sassi
authors.affiliation: Centre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, France Institut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, FranceCentre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, FranceInstitut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Dion
authors.affiliation: Centre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, France Institut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, FranceCentre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, FranceInstitut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Lerat
authors.affiliation: Centre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, France Institut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, FranceCentre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, FranceInstitut National de la Recherche Agronomique, Unité Biopolymères, Interactions, Assemblages, UR1268, Rue de la Géraudière, BP 71627, 44316 Nantes, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Lahaye
keywords: Ulva armoricana; Ulva rotundata; extraction yield; gelling properties; green tides; physicochemical characteristics; seasonal variability; ulvan