Bioaccessibility and colonic catabolism of carotenoids from mango purée (cv. Osteen): comparison of ileal fluid content and products of in vitro digestion

Abstract

The bioactivity of carotenoids depends largely on their stability during passage through the gastrointestinal tract and absorption into the circulatory system. Mango (Mangifera indica L.) is an important dietary source of carotenoids, and this is the first study to compare the metabolic fate of mango carotenoids using in vitro models and in vivo measurements of human ileal fluid. Carotenoid stability was evaluated using a simulated in vitro gastrointestinal digestion model, with oral, gastric and intestinal phases, followed by colonic fermentation. The findings were compared with in vivo data from ileal fluid collected after mango purée consumption. Ten carotenoids were identified in the purée, with β-carotene being the predominant component. In vitro, mango carotenoids remained relatively stable after the oral phase (∼90% recovery). They were partially degraded after the gastric phase (∼70% recovery) and significantly reduced under small intestine conditions (∼30% recovery), with carotenes being degraded more extensively than xanthophylls. In vivo, carotenoid recovery in ileal fluid collected 0–24 h post-consumption was ∼23% of intake, with marked inter-individual variability (7–43%). These findings indicate that carotenoid absorption occurs primarily in the upper GI tract, with smaller amounts reaching the large intestine to potentially interact with the gut microbiota. After in vitro fecal fermentation, a minor fraction of carotenoids remained intact, suggesting limited colonic availability. Overall, the results highlight the stability of carotenoids as a key factor strongly influencing their bioavailability in humans. The study was registered with the University of Ulster Ethics Committee: REC/19/0097 and ClinicalTrials.gov: NCT06182540.