Formation, characterization and delivery of quercetin-loaded α-lactalbumin fibril-based hydrogels through metal ions

The purpose was to apply metal ions to induce the formation of α-lactalbumin fibril-based hydrogel to create a versatile nano-carrier for effective quercetin encapsulation and delivery. Quercetin could be successfully embedded into the hydrogel primarily through hydrogen bonding and hydrophobic interaction, as demonstrated by FTIR and XRD. Quercetin encapsulation effectiveness in α-lactalbumin fibril-based hydrogel via metal ions was up to 91.82 %, 7.41-fold higher than that with α-lactalbumin directly. Rheological results revealed elasticity was the dominant behavior of these hydrogels and quercetin addition could lead to a slight decrease of both G′ and G″, presumably due to the formation of soluble macroparticle aggregates and insoluble aggregates caused by polyphenol like quercetin. Quercetin bioaccessibility was increased to 32.62 % by 2.82-fold with this hydrogel. Additionally, the hydrogel demonstrated strong UV stability, antioxidant activity, and water retention. This research could provide practical and theoretical support to widen the development of new α-lactalbumin-derived food products.