Enhancing the stability and functionality of phycobiliproteins as natural food colourants through microparticle...

The food industry is increasingly turning to microalgae pigments as natural functional colourants to replace potentially harmful synthetic dyes. Among those, phycobiliproteins offer deep and vibrant colours with bioactivities, showing to be a promising alternative. However, incorporating them into a food matrix can be challenging due to their inherent instability, low bioavailability, and off-flavours. Accordingly, the present work aimed to prepare microparticles of phycocyanin (PC_MP) and of an ultrasound-assisted phycoerythrin-rich extract from Porphyridium purpureum (PE_MP) to improve these natural colourants' stability and functional properties. The microparticles were prepared by Nano spray-drying using inulin and gum Arabic as coating materials, resulting in particles with high yield, encapsulation efficiency (from 69 % to 80 %), solubility, and colour retention. Combining inulin and gum Arabic allowed the formation of smaller and more homogeneous particles with increased antioxidant potential when compared to using inulin alone. Moreover, gum Arabic improved the bioaccessibility of PE_MP from 35 % to 51 %, demonstrating the potential of this microparticle formulation to enhance the stability and functionality of phycobiliproteins.