Effects of processing on the chemical, physicochemical, enzymatic, and volatile metabolic composition of pitaya (Hylocereus polyrhizus (F.A.C. Weber) Britton & Rose)

Abstract

The effects of processing on the chemical, physicochemical, enzymatic, and volatile metabolic composition of pitaya pulp were assessed for the first time. To this end, the following treatments to obtain pitaya pulp were evaluated: Treatment A (TA, pulp processing without ascorbic acid), Treatment B (TB, whole fruit processing with ascorbic acid), and Control (whole fruit processing without ascorbic acid). The treatment employed in TB resulted in low polyphenol oxidase and peroxidase activity, and no significant chemical or physicochemical alterations in most parameters evaluated. In addition, TB presents high yields and fiber content compared to the TA or Control. For metabolic analysis, Gas Chromatography-Mass Spectrometry (GC-MS) was effective for the simultaneous determination of 80 volatile metabolites in pitaya. Chemometric analyses was used to efficiently distinguish the volatile compounds of each treatment, and demonstrated that TB presents an interesting volatile profile due the conservation or agregation of compounds.

Keywords: CG-MS; Chemometric analysis; Peroxidase; Polyphenol oxidase; Volatile metabolites.