Encapsulation of Ethanolic Extract of Red Pitaya (Hylocereus polyrhizus) Using Gelatin-Pectin: A Comparison of Stability and Antioxidant Activity Between the Extract and the Nanocapsule

Introduction: Dragon fruit is a tropical fruit from the cactus family, known for its high nutrient and fiber content. This study investigates the antioxidant potential of red pitaya (Hylocereus polyrhizus), comparing its ethanolic extract with its microencapsulated form using a gelatin-pectin matrix. Red pitaya is rich in betalains, which contribute to its strong antioxidant, anticancer, and antimicrobial properties. However, betalains are unstable and susceptible to degradation under various conditions. Methods: The ethanolic extract of red pitaya was encapsulated through freeze-drying. The resulting nanocapsules were characterized using SEM and FTIR analyses. We also compared the stability of the extract and nanocapsules, total phenol content, and antioxidant activity. Results: The encapsulation efficiency was approximately 48%. The antioxidant activity of the nanocapsules, with a mean diameter of 0.41 nm, was evaluated using the DPPH assay, which revealed that the nanocapsules exhibited superior antioxidant capacity compared to the ethanolic extract. Although the total phenolic content of nanocapsules was lower than that of the extract, the nanocapsules effectively released phenolic compounds and demonstrated greater stability at high temperatures than the extract. Discussion: Encapsulation significantly improved the thermal stability and antioxidant performance of red pitaya extract, demonstrating its effectiveness in preserving sensitive bioactive compounds. Conclusion: These findings suggest that encapsulation enhances the stability and efficacy of betalains, positioning the nanocapsules as a potential natural additive for functional foods and nutraceuticals.