Improving benzyl – isothiocyanate bioaccessibility in white mustard (Sinapis alba) sauce through spray – drying microencapsulation and Pickering emulsions

This study compared the bioaccessibility and behaviour of different formulations of benzyl - isothiocyanate (benzyl - ITC) prepared using different approaches and the INFOGEST in vitro digestion protocol. The aim was to improve the low bioaccessibility of this bioactive compound caused by its lipophilic properties. Spray-dried microparticles were prepared using a matrix of either mannitol or maltodextrin, and compared with Pickering emulsions produced with cellulose nanofibres. The different systems were characterised and their ability to associate benzyl - ITC determined. The in vitro digestion characteristics provided by the different systems was evaluated. Microencapsulation of benzyl-ITC by spray-drying was not successful when mannitol was used as excipient, while maltodextrin resulted in a production yield around 70 % with an ITC association efficiency up to 75 %. Nevertheless, significant improvement of benzyl - ITC bioaccessibility in a mustard sauce was not achieved. In contrast, the formulation of benzyl - ITC in a Pickering emulsion prepared with cellulose nanofibres showed an association efficiency of around 100 % and high bioaccessibility with values up to 77 %. The chemical similarity between the mixed micelles formed for lipid absorption in the small intestine, and the structure of cellulose nanofibre emulsion could justify the observed improvement.