Construction of glycosylated zein-based colloids to simultaneously improve fucoxanthin’s thermal processing adaptability, digestive stability, and oral bioavailability

Fucoxanthin (FX) is a carotenoid found in marine environments with a range of nutritional functions. However, its application in the food industry has been restricted by its vulnerability to deterioration and absorption challenges. This study employed zein to develop hydrophilic colloids to enhance the thermal processing adaptability, gastrointestinal digestive stability, and oral bioavailability of FX. The findings demonstrated that the using glucose for the grafting modification of zein caused a deviation in its isoelectric point, reduced its water contact angle, and altered its secondary structure, resulting in higher hydrophilicity. Using glycosylated zein (GZ) for FX loading yielded homogenous, stable aqueous GZ-FX complex dispersion solutions with an encapsulation efficiency (EE) > 85.00 %, a particle size < 210.00 nm, a zeta-potential > −30.00 mV, and a polydispersity index (PDI) < 0.30. GZ-based encapsulation notably enhanced the thermal stability of FX, retaining approximately 90.00 % and 80.00 % of the FX at 65 ℃ and 100 ℃, respectively. During in vitro simulated gastrointestinal digestion, GZ-encapsulation of FX demonstrated a retention increase of 30.63 % and a 2.31-fold higher micellization rate. The in vivo absorption results showed that GZ-based encapsulation dramatically increased FX oral bioavailability, while its serum, liver, and kidney response levels were 51.49-fold, 5.13-fold and 6.73-fold higher. This study suggests that glycosylated alcohol-soluble proteins are highly effective carriers for delivering carotenoids, with significant application potential in the food industry.