Red pitaya (Hylocereus polyrhizus) as a source of betalains and phenolic compounds: Ultrasound extraction, microencapsulation, and evaluation of stability

Abstract

There is an increasing demand for natural pigments in food production, but challenges are related to the existence of matrices rich in these pigments, the optimization of extraction conditions and the preservation of pigments. Pitaya, the fruit of Hylocereus polyrhizus is considered a good source of betalains and phenolic compounds; therefore, they were extracted from its pulp by ultrasound-assisted extraction, the extract was encapsulated by spray drying, and the stability of the microencapsulated pitaya pulp extract (MPPE) was studied. MPPE showed satisfactory results of solubility, hygroscopicity, encapsulation efficiency and antioxidant activity. After 90 days of storage, MPPE showed reductions in betalains and phenolic compounds contents of only 14.28% and 11.88%, respectively, which indicates that the extract has great potential as an ingredient and/or functional pigment for application in the food and pharmaceutical industries.