Glutathione Delivery Using a Furcellaran-Chitosan System: Effects of Microencapsulation and Incorporation Strategy on...

The aim of this study was to evaluate the impact of glutathione (GSH), applied in free form and in the form of microcapsules, on the release and nutritional properties of a functional post-exercise recovery snack. Five snack variants enriched with free GSH or microencapsulated GSH, applied using different incorporation strategies, were prepared and subjected to standardised in vitro digestion following the INFOGEST protocol. The study assessed GSH levels in the digesta, protein and fat digestibility, antioxidant capacity, and changes in fatty acid profiles after digestion. Snacks fortified with free GSH exhibited the highest immediate GSH levels in the digesta (up to 2390 ± 240 nmol/mL), whereas lower levels were observed for microencapsulated GSH (down to 1280 ± 132 nmol/mL), reflecting differences in release behaviour under in vitro digestion conditions. Products containing microencapsulated GSH showed a markedly higher post-digestion free amino acid content (1520 ± 100 mg/100 g) compared with those enriched with free GSH (820.3 ± 19 mg/100 g), indicating differences in the profile of protein digestion products. Antioxidant activity and phenolic content increased after digestion across all formulations, with no consistent differences between variants, while fat digestibility remained unchanged, although fatty acid profiles differed depending on the GSH application form. Overall, the results indicate that the form of GSH incorporation, including microencapsulation, influences its behaviour during in vitro digestion and affects the release and distribution of compounds within the food matrix.