Optimized Microwave-Assisted Extraction of Betalains from Pitahaya Peel and Their Application in Functional Tortillas

The present work aims to optimize the extraction of betalains from pitahaya peel using microwave-assisted extraction and to microencapsulate the resulting compounds by spray drying for incorporation into tortilla formulations, thereby conferring functional properties. Extraction optimization was performed using a central composite design, evaluating the effects of the factors: power (200, 500, and 800 W) and time (30, 60, and 90 s). As a result, extraction time had a statistically significant effect on betalain extraction (p ≤ 0.05), whereas microwave power did not (p ≤ 0.05). The optimal conditions were 100 W of power and 65 s of extraction time, yielding an experimental maximum extraction of 1526.57 ± 19.62 μg/g of total betalains. Tortillas were formulated with concentrations of 0, 5, and 10% microcapsules, showing a significant increase (p ≤ 0.05) in antioxidant activity (from 2.5 to 10.9% inhibition) as measured by both the DPPH and ABTS methods, and in total betalain concentration. Concluding that the incorporation of microcapsules with pitahaya peel extracts into tortillas promotes a significant increase in betalain concentration and antioxidant activity. These findings support the potential of pitahaya peel extracts obtained via microwave extraction as a strategy for developing functional foods with antioxidant benefits.