Multielement Composition and in Vitro Bioaccessibility in Brazilian Edible Floral Supplement Capsules Containing...

Dandelion (Taraxacum officinale) and hibiscus (Hibiscus sabdariffa) are notable unconventional edible flowers (UEFs) that have traditionally been used as food and in herbal preparations. This study examined the in vitro bioaccessibility content of six elements (Cr, Cu, Fe, Mn, Ni, and Zn) in edible flower capsules sold in Brazil. Acid digestion in a closed system and microwave-induced plasma optical emission spectrometry (MIP OES) were employed, as well as simulated gastrointestinal digestion according to the INFOGEST 2.0 in vitro protocol. Additionally, we examined the contribution of the in vitro bioaccessible fraction (FBio) in relation to the recommended daily intake (RDI). The concentrations (in µg g⁻¹) of the target elements were as follows: Cr (< 0.46-2.82), Cu (< 0.48-11.45), Fe (159.44-1880.90), Mn (48.94-441.34), Ni (< 0.44-3.21), and Zn (< 0.55-30.98). The FBio of the evaluated elements ranged from 0.13% to 14.31%. Although Fe had high total levels, its bioaccessibility was limited, contributing only 0.13%. In contrast, Mn and Ni exhibited high gastrointestinal release, accounting for 12.13% and 14.31% of the FBio, respectively. Mn showed high gastrointestinal release, providing up to 209.3% of the RDI. This study is the first to specifically evaluate the bioaccessible trace element content of these edible flowers using the INFOGEST 2.0 in vitro protocol and MIP OES to assess microelements. Overall, the results highlight the importance of incorporating chemical composition and bioaccessibility data into the multi-element characterization of dandelion and hibiscus.