STUDY OF SOME BIOACTIVE COMPOUNDS OF WHITE- AND RED-FLESHED PITAYAS (CEREUS UNDATUS, SYNONYMY: HYLOCEREUS GUATEMALENSIS, H. UNDATUS)

The pitaya (Cereus undatus, synonymy: Hylocereus guatemalensis, H. undatus) is an exotic fruit whose consumption is slightly increasing in our country. The functional properties commonly attributed to this fruit prompt the study of its physical, chemical and microbiological characteristics. It should be emphasised that fruits are primary sources of several vitamins and other bioactive compounds, such as antioxidants, vitamins and sugars. The intake of these compounds enhances individuals' immunity, leading to better health levels and improving their physical and mental performance. The reference values for pitaya are still unknown to the general public, since it is a fruit consumed by a wealthy class, as its price is excessively high by Brazilian standards. Food matrices are very complex, given their natural characteristics. In view of this, several techniques are used for the analytical determination of bioactive compounds, among them High-Performance Liquid Chromatography (HPLC) and ultraviolet–visible spectrophotometry. The aim of this work is to study the presence of vitamin C and sugars in white- and red-fleshed pitayas by HPLC, as well as to determine the antioxidant activity content by the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid – ABTS) radical scavenging method, soluble solids content (ºBrix), in addition to acidity and pH.