Development of food packaging bioactive aerogels through the valorization of Gelidium sesquipedale seaweed

This study presents the valorization of the Gelidium sesquipedale seaweed for the development of bioactive

aerogels with interest in food packaging applications. The raw seaweed was used to extract cellulose, highly

crystalline (Xc∼70%) and high aspect ratio (∼40) nanocellulose and an agar-based extract, rich in polyphenols

and with antioxidant capacity. Subsequently, pure PVA and hybrid aerogels containing cellulose and nanocellulose

were produced by a physical cross-linking method. The presence of hydroxyl groups provided by the

high aspect ratio of nanocellulose promoted the interactions with water and facilitated the accessibility of

moisture towards the interior of the aerogels, hence generating high water sorption capacity materials.

The agar-based extract was then incorporated into selected formulations and the release in hydrophobic and

hydrophilic food simulant media was investigated. Pure PVA aerogels dissolved in aqueous media, resulting in

an immediate release of the bioactive. Interestingly, the hybrid aerogels containing cellulose and nanocellulose

preserved their integrity and provided a more gradual release. Although the hybrid aerogels presented similar

release profiles during the first 48 h, the presence of nanocellulose led to greater release values after more

prolonged times. This shows the promising properties of hybrid PVA/cellulose/nanocellulose aerogels as matrices

for the controlled release of bioactive compounds in food systems, which could be of interest for the

development of bioactive packaging structures.