Unveiling fucoxanthin's fate: In vitro gastrointestinal digestion effects on bioaccessibility, antioxidant potential, colour changes, and metabolite profiles.

Limited knowledge of fucoxanthin's changes during digestion necessitates comprehensive investigation to ensure its efficacy as a functional ingredient. This study assessed the effects of digestion on fucoxanthin's bioaccessibility, antioxidant activity, colour changes, and metabolite formation through in vitro gastrointestinal digestion. Results indicated the highest bioaccessibility during gastric digestion (0.03 ± 0.00 mg/mL), followed by intestinal and mouth with 0.012 ± 0.00 and 0.011 ± 0.13 mg/mL, respectively. Antioxidant activity was the highest at the gastric stage, with significant activity persisting post-digestion (P < 0.05). Colour changes were significant, with total colour differences (∆E*) of 2.40, 2.86, and 2.76 at the mouth, gastric, and intestinal stages, respectively. LC-MS/MS-based metabolomics analysis revealed 15 key metabolites, with carboxylic acids as major metabolites during gastric and intestinal stages. Pearson correlation analysis demonstrated a significant correlation between identified metabolites with bioaccessibility, antioxidant activity, and colour changes, underscoring fucoxanthin's potential as a promising functional food ingredient.