In Vitro Gastrointestinal Digestion Impact on the Antioxidant Activity of Extracts Produced from the Macroalgae Gracilaria gracilis and Ulva rigida

edible algae their richness molecules nutritional been described as a source of bioactive peptides, scientifically documented antioxidant, anti-hypertensive and antimicrobial properties. water-soluble extracts were produced from the macroalgae Gracilaria gracilis and Ulva rigida with focus on their antioxidant potential. Furthermore, the impact of in vitro gastrointestinal (GI) digestion on the antioxidant activity of both extracts was studied, with the goal of evaluating their potential as functional food ingredients. compared to the non-digested extract, being statistically significant after stomach digestion, for G.gracilis extract (p<0.05). On this study, both extracts maintained their antioxidant activity during in vitro GI digestion, with an increase after almost all digestion phases, when compared to the non-digested extract. The observed increase may be explained by the production of smaller and more bioactive peptides, by the action of the gastrointestinal enzymes, such as pepsin and pancreatin. In conclusion, since antioxidant activity is maintained throughout the GI tract, these results showed that G.gracilis and U.rigida extracts may be considered potential ingredients for the development of functional foods with antioxidant properties.