Antioxidant fortification of yogurt with red cactus pear peel and its mucilage

The addition of red cactus pear peel and its mucilage on color, bioactive compounds and antioxidant capacity (AC) of yogurt was investigated. Peel and its mucilage were dried and used for the formulation of different yogurt blends following a constrained mixture design. Color, total phenolic compounds, total flavonoids, total betalains and AC were evaluated in formulated yogurts. An optimization process was conducted thereafter, and the bioactive compounds and AC of this yogurt were evaluated before and after gastrointestinal simulation. Results indicated that cactus pear peel and its mucilage give a nice magenta color to the yogurts, and also increase the bioactive compounds and AC of them. Optimization procedure indicates that yogurt formulated with 5.5% of cactus pear peel and 7.5% of mucilage displays the highest bioactive compounds and AC; moreover, they were significantly increased (p < 0.05) by the simulated gastrointestinal process.