INTERACTIONS BETWEEN VOLATILES AND LIPIDS IN COMPLEX-SYSTEMS

Partition equilibria of three aroma compounds in three different bipha sic systems were studied by a liquid/liquid partition technique to inv estigate interactions that occur between volatiles and lipids in bipha sic solutions. The lipids used were linoleic acid and ricinoleic acid and tetradecane as a model. The three aroma compounds were ethyl aceta te, 2,5-dimethylpyrazine, and oct-1-en-3-ol. The results showed that t he intermolecular forces involved were weak. Infrared spectroscopy was then performed on binary systems (tetradecane and linoleic acid or ar oma compound) and on ternary systems (tetradecane, linoleic acid, and aroma compound) to determine the nature of the interactions. This meth od confirmed the presence of hydrogen bonds between linoleic acid and 2,5-di- methylpyrazine or oct-1-en-3-ol and also between molecules of oct-1-en-3-ol when the latter are present at high concentrations in li pids. The observations provided sufficient information to explain the behavior of oct-1-en-3-ol in biphasic solutions, but further work is n eeded to fully elucidate the nature of interactions between ethyl acet ate or 2,5-dimethylpyrazine and lipids and also to explain the behavio r of these compounds in biphasic solutions.