**Abstract**

This study aimed to analyze the effect of incorporating different concentrations (10, 20 and 30% (w/w)) of the brown seaweed *Macrocystis pyrifera* into white maize tortillas in terms of chemical composition, color, texture, phenolic compounds, and antioxidant capacity. The moisture and lipid content decreased with the addition of seaweed, while the ash, protein and fiber content increased. The changes in carbohydrates were not significant (p > 0.05). The concentration of Na, K, Mg, and P increased significantly (p < 0.05) with the incorporation of the alga. Higher percentage of seaweed led to *masa*s and tortillas with greener tones as it affected L\*, a\*, b\* parameters, hue and chroma and to bigger differences between the control samples and the samples with seaweed. Total phenolic content increased linearly with the incorporation of seaweed, as well as FRAP values. While the *masa* with 20% of seaweed showed the highest percentage of ABTS inhibition (86%). Finally, the control sample of *masa* presented the lowest values of adhesiveness and hardness, while the control sample of tortilla showed the highest hardness value.

**Keywords:** seaweed, *Macrocystis pyrifera*, white maize, tortilla, mineral profile, texture profile analysis, antioxidant capacity
