Hydroxypropyl methylcellulose-modified whey protein concentrate microcapsules for the encapsulation of tangeretin

The oral bioavailability of tangeretin is limited by its low water solubility and high crystallisation. In the present study, tangeretin was entrapped in whey protein concentrate (WPC)-stabilised emulsions to enhance its bioaccessibility. Hydroxypropyl methylcellulose (HPMC) was added to modify the interface of the emulsion droplets, and Ca2+-crosslinking was used to induce the gel formation. Spray drying of the emulsions or gels enabled to produce microcapsules. The physicochemical characteristics and in vitro digestion behavior of the microcapsules were investigated. Results indicated that HPMC modification and Ca2+-crosslinking increased the average particle size, altered the microstructure, ameliorated the quality of the WPC-based microcapsules and improved the encapsulation efficiency of tangeretin. Furthermore, the in vitro studies showed that HPMC modified and Ca2+-added microcapsules could control the release of free fatty acid. HPMC greatly increased the bioaccessibility of tangeretin from around 28% to 80%. Overall, these results confirmed that HPMC-modified WPC microcapsules could be a promising carrier to protect hydrophobic functional ingredients and improve their oral bioavailability.