Sulfate groups position determines the ionic selectivity and syneresis properties of carrageenan systems

Said Elmarhoum (1) , Sophie Mathieu (2) , Komla Ako (1) , William Helbert (2)

1 LRP - Laboratoire Rhéologie et Procédés
2 CERMAV - Centre de Recherches sur les Macromolécules Végétales

The salt sensitivity and selectivity feature of α-carrageenan (α-Car) were investigated and compared with κ-carrageenan (κ-Car) and iota-carrageenan (ι-Car). These carrageenans are identified by one sulfate group on the 3,6-anhydro-D-galactose (DA) for α-Car, D-galactose (G) for κ-Car and on both carrabiose moieties (G and DA) for ι-Car. The viscosity and temperature, where order-disorder transition have been observed, were greater in presence of CaCl 2 for α-Car and ι-Car compared with KCl and NaCl. Conversely, the reactivity of κ-Car systems were greater in presence of KCl than CaCl 2. Unlike κ-Car systems, the gelation of α-Car in presence of KCl was observed without syneresis. Thus, the position of sulfate group on the carrabiose determines the importance of counterion valency too. The α-Car could be a good alternative to κ-Car to reduce the syneresis effects.

Mots clés: Alpha-carrageenan; Sulfate group position; Anhydro-ring; Viscosity; Salt sensitivity; Syneresis

Domaines: Chimie

Said Elmarhoum, Sophie Mathieu, Komla Ako, William Helbert. Sulfate groups position determines the ionic selectivity and syneresis properties of carrageenan systems. Carbohydrate Polymers, 2023, ⟨10.1016/j.carbpol.2022.120166⟩. ⟨hal-03812613⟩