(444e) Smart Membranes for Flavor Delivery

Flavorings often contain volatile compounds, so in the absence of encapsulation, they are vulnerable to premature release. Encapsulation also offers protection against environmental damage such as oxidation, light-induced reactions, etc. For processed foods, the ideal flavor would survive the temperature excursion during cooking, remain in the product for days to months and then be released instantaneously in the mouth. In the mouth, flavors are released due to mechanical disruption of the gelatin encapsulant and due to enhanced permeability of the gelatin in the moist environment.

This work has focused on the use of temperature responsive gels (TRGs) for flavor retention at cooking temperatures. TRGs are polymeric hydrogels with a large temperature-dependent change in volume. Specifically, we have studied a system with a lower critical solution temperature (LCST). This type of system exhibits a two phase region at elevated temperatures. A gel featuring a LCST exhibits swelling at low temperatures and collapse at high temperatures. In the collapsed state, the polymer acts as a transport barrier, keeping the volatile flavors inside. We have successfully modified a cellulose polymer to exhibit this volume change and have encapsulated an oil phase inside the gel.