EXTRACTION OF SWEET POTATO (Ipomoea batatas L.) ANTHOCYANINS AND THEIR APPLICATION AS A NATURAL DYE IN YOGURT

Resumen

The aim of this investigation was to obtain a natural dye by ultrasound-assisted extraction from purple sweet potato (Ipomoea batatas L.) for its application in yogurt. The extraction parameters were optimized using a Box-Behnken design and response surface methodology in 15 treatments. Temperature, ethanol concentration, and sonication time were the variables studied in the extraction process, with anthocyanin concentration serving as the response variable, which was determined using the differential pH method. Treatment T11 was identified as the best treatment, with the following extraction conditions: a temperature of 60 °C, ethanol concentration of 60.16 %, and sonication time of 20 min. The concentration of anthocyanins fluctuated between 59.7 and 66.47 mg of cyanidin-3-glucoside L^-1. From T11, three yogurt samples were formulated with 0.6, 0.8, and 1 % of extract and a control without any addition (0 %). These samples were evaluated through sensory analysis with a hedonic scale of nine points with 50 panelists. The formulations with anthocyanins received favorable scores; the yogurt with 1 % dye stood out for having the highest acceptance in terms of color, although for the remaining attributes (flavor, aroma, and consistency), the yogurt with 0.8 % scored higher. In general, all samples with natural dye obtained an acceptable evaluation. Therefore, the extract can be used as a natural dye in yogurt without issue, making it a viable alternative to synthetic dyes and potentially leading to the development of functional foods due to its bioactive compound content.