Obtención de un colorante natural a partir Tropaeolum tuberosum Ruíz & Pavón para su aplicación en yogur

This study aimed to obtain a natural dye through ultrasound-assisted extraction from Tropaeolum tuberosum Ruíz & Pavón for application in yogurt. A Box-Behnken design optimized the extraction parameters using response surface methodology. The study variables for extraction were temperature, ethanol concentration, and time. In contrast, the response variables were the total content of anthocyanins and polyphenols, determined by the differential pH and Folin-Ciocalteu methods, respectively. The optimal extraction conditions were a temperature of 48 °C, ethanol concentration of 33.93%, and 20 minutes. The yield of anthocyanins and polyphenols ranged from 347.34 to 419.92 mg eq. cyanidin-3-glucoside/L and from 63.68 to 105.09 mg/100 g, respectively. The optimized extract exhibited an antioxidant capacity of 0.275 ± 0.003 mM Trolox eq./mL, determined by the DPPH method. Three yogurt formulations (2%, 4%, and 6% v/v of extract) and control (0% v/v) were prepared and subjected to sensory evaluation for acceptability using a 9-point hedonic scale with 60 panelists. The yogurt with 6% showed higher acceptability than other colored yogurt samples. The obtained extract can be used as a natural dye in yogurt, serving alternative to synthetic colorants, to develop potentially functional foods due to their bioactive compound content.