Unveiling Fucoxanthin's Fate: In Vitro Gastrointestinal Digestion Effects on Bioaccessibility, Antioxidant Potential, Color Changes, and Metabolite Profiles

Abstract

Metabolic processes in the digestive tract transform fucoxanthin, a carotenoid produced by microalgae with potential medicinal and food uses. Previous studies on in vitro gastrointestinal simulation focused on fucoxanthin bioaccessibility but did not extensively explore its effects on antioxidant activity, color changes, and metabolite formation. This study addresses these gaps, showing that fucoxanthin's highest bioaccessibility index occurs during gastric digestion, with a content of 0.03 ± 0.00 mg/mL (p<0.05), significantly higher than at the end of digestion (0.012 ± 0.00 mg/mL). The highest antioxidant activity was also observed at the gastric stage. LC-MS/MS-based metabolomics analysis revealed fifteen prominent metabolites, including carboxylic acid, ketone, and apo-carotenals. Pearson correlation analysis indicated a significant correlation between these metabolites and bioaccessibility, antioxidant activity, and color changes (p<0.01). This study enhances understanding of fucoxanthin digestion and promotes sustainability in food products and practices.

Keywords: Fucoxanthin, Bioaccessibility, Simulated gastrointestinal digestion, Antioxidant activity, Metabolomics, Microalgae, Sustainability