Revealing the influence on nanoparticle formation and antioxidant efficacy from aging in Liupao tea via integrated physicochemical, metabolomic, and elementomic approaches.

Nanoparticles are bioactive carriers with significant application value, and the aging influence on the formation and bioactivity of Liupao tea nanoparticles (LTNs) was investigated in this study. Stable spherical nanoparticles with diameters of 100-500 nm were present in Liupao tea infusions, and polysaccharides as well as proteins were their primary components. Multi-omics analysis showed that glycosylated flavonoids accumulated in LTNs5 and LTNs15, and amino acids and K were enriched in LTNs5, LTNs10, and LTNs15, which were associated with smaller particle size and higher antioxidation. In contrast, methylated flavonoids, methylxanthine alkaloids, Ca, Al, and Mn concentrated in samples with larger particle sizes and lower antioxidation, such as LTNs0, LTNs3, and LTNs8. Interestingly, consistent changes of polyphenols and Cu suggested a potential synergistic role in the formation and bioactivity of LTNs. Overall, these findings enhanced the understanding of the connection between vintage quality and functional value in Liupao tea.