Co-delivery of phycocyanin and astaxanthin using nanocochleates as a novel delivery vehicle: Effects of pigment concentration on physicochemical, structural, and in vitro digestion properties

Astaxanthin and phycocyanin offer health benefits, but their stability and bioavailability are limited, restricting food industry use. This study explores nanocochleates to improve stability and enable controlled release of these pigments in simulated gastrointestinal conditions. Nanocochleates co-loading 5 mg of astaxanthin and 5 mg of phycocyanin achieved the highest encapsulation efficiency, along with the smallest particle size, lowest polydispersity index, and highest antioxidant activity. The co-delivered nanocochleates showed significant stability over 28 days at both 4 °C and 25 °C. SEM revealed cylindrical structures with uneven surfaces, supporting dynamic light scattering results. DSC and FTIR spectroscopy confirmed the successful formation of nanocochleates and their effective co-delivery of astaxanthin and phycocyanin. Laurdan fluorescence and XRD show that Ca²⁺ reduces membrane fluidity and enhances lipid packing. Fickian transfer primarily drives the release of astaxanthin and phycocyanin, making nanocochleate a promising advancement for controlled pigment release in the food industry.