Influence of Qingzhuan Tea Polysaccharides on F^– Adsorption: Molecular Structure, Binding Behavior, and <i>In Vitro</i> and <i>In Vivo</i> Digestion and Metabolism

The high level of fluoride in Qingzhuan tea (QZT) poses a potential health risk to consumers. This study aims to explore the binding behavior of purified Qingzhuan tea polysaccharides (pTPS) and fluoride ions (F^-), as well as their regulatory role in the digestion and metabolism of fluoride. The sugar content of pTPS was 94.64 ± 3.01%, with a molecular weight of 7.373 × 10⁴ Da and high homogeneity. The effects of different proportions and environmental conditions on the adsorption of F^- by pTPS were investigated. The influence of the complexation of pTPS and F^- on the digestion and metabolism of fluoride was explored using an <i>in vitro</i> gastrointestinal digestion model and C57BL/6 mice. The structural alterations of pTPS were observed during simulated gastrointestinal digestion. Furthermore, pTPS were found to reduce serum fluoride levels and inhibit accumulation in major organs and tissues, especially the heart, liver, kidneys, muscles, and femur. This study investigated the binding pattern between fluorine and pTPS and its influence on the digestion and absorption of fluorine, providing a promising potential for pTPS as a bioadsorbent of fluorine to alleviate the toxicity of fluorine in QZT, which laid a theoretical foundation for the safety of consumption of QZT.