Encapsulation of volatiles in nanofibrous polysaccharide membranesfor humidity-triggered release

A single-step electrospinning process will be applied to a blend of edible carbohydrate polymers (pullulanand -cyclodextrin) to encapsulate bioactive aroma compounds and allow a humidity-triggered release.The encapsulation is rapid and efficient and the final product is an active nanofibrous membrane that canbe directly used for food or active packaging applications. The membrane hosts small and homogeneouslydispersed crystals of cyclodextrin–aroma complexes which are formed during the electrospinning. Withthis type of structure, the release of aroma compound is negligible at ambient conditions (23◦C and 55%UR) even at high temperature (up to 230◦C), and it occurs beyond a given relative humidity threshold(90%), useful for food packaging applications. The mass fraction of free aroma released is directly relatedto the water activity of the system, namely, ϕ = anW/(anW+ Kapp) explaining the observed key role playedby the relative humidity on the release of the aroma compounds.