Enhancing the water dispersibility and intestinal targeting of pterostilbene using tannic acid-whey protein...

In this study, three types of whey protein isolate (WPI)-tannic acid (TA) covalent conjugates (WPI-TA) were synthesized via alkaline treatment, free radical-induced method, and laccase induction. These conjugates were subsequently utilized in the antisolvent precipitation method to encapsulate pterostilbene (Pte). The structural and functional properties of these conjugates as carriers for intestinal-targeted Pte delivery were thoroughly evaluated. SDS-PAGE, total phenolic content measurement, grafting efficiency, and FT-IR analysis confirmed the successful formation of three distinct covalent conjugates. Among them, the laccase-induced WPI-TA conjugates exhibited the highest TA grafting efficiency. The particle size of this conjugate was measured at 115.25 nm with a PDI of 0.31. Upon encapsulation of Pte, this conjugate exhibited superior thermal stability, enhanced antioxidant properties, and sustained release within the gastrointestinal tract. The water solubility of Pte in these nanoparticles was found to be 361.19 times higher than that of free Pte, presenting a promising strategy for targeted intestinal delivery of Pte.