VISCOELASTIC PROPERTIES OF L-CARRAGEENAN GELATIN MIXTURES/

The storage (G') and loss (G '') moduli of transparent mixtures of l-c arrageenan and gelatin have been measured during gelation and melting and compared with those of gelatin and l-carrageenan systems alone. Th e moduli of the mixtures were always higher than the sum of those of t heir components alone. Gelatin and l-carrageenan seem to reinforce eac h other. Three specific temperature domains can be distinguished, deli mited by the melting and helix-coil transition temperatures of gelatin and l-carrageenan. An interpretation based on conformational changes and an attractive electrostatic interaction between the two biopolymer s is suggested. The temperature dependence of G' and G '' for mixtures has been studied as a function of thermal history (time and temperatu re of gel ageing), sodium chloride concentration and molecular weight of the l-carrageenan. Copyright (C) 1996 Elsevier Science Ltd.