Gastrointestinal bioaccessibility and fiber mitigation of tropane alkaloids assessed on tea and cookies by in vitro digestion

Abstract

BACKGROUND: Tropane alkaloids (TAs) are toxic compounds with a high anticholinergic effect. They have been widely analyzed in food samples, but their fate in the gastrointestinal tract has not been evaluated yet. RESULTS: In this study, static in vitro digestion was performed to assess gastrointestinal bioaccessibility of the most common TAs on tea and home-made cookies. Cookies enriched with dietary fiber (pectin, arabinogalactan, and κ-carrageenan) were also tested to evaluate their influence on TA bioaccessibility. Two extraction methods and a liquid chromatography–mass spectrometry method were optimized and validated. Bioaccessibility for tea (60–105%) was higher than for cookies (39–93%) (P = 0.001–0.002), which indicates TAs could be more easily absorbed when they are contaminating tea. Digestion of cookies enriched with 50 g kg−1 of different fibers showed that, although no significant changes were observed in the gastric phase (P = 0.084–0.920), duodenal bioaccessibility was significantly reduced (P = 0.008–0.039). Pectin was the fiber with a better mitigation effect for all the compounds. CONCLUSION: TAs bioaccessibility was determined after in vitro digestion of contaminated tea and cookies. Dietary fiber seems to be a promising mitigation strategy, significantly reducing TA bioaccessibility percentages. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.