Microfiltered red-purple pitaya colorant: UPLC-ESI-QTOF-MSE-based metabolic profile and its potential application as a natural food ingredient.

Complete characterization of microfiltered red-purple pitaya colorant (MRPPC) and its potential applications in foods is described. Using sensorial analysis, products that use carmine or beetroot dye as a food colorant in their formulations were compared. The effect of storage under refrigeration on the microbiological, physicochemical, and chemical changes of MRPPC were evaluated. The results showed that UPLC-ESI-QTOF-MSE was effective for the simultaneous determination of twenty metabolites, putatively identified as carbohydrates, flavonoids, and betalains. The MRPPC was shown to have microbiological and physicochemical stability through twelve weeks of storage, and chemometric analyses efficiently distinguished the metabolic profile in each storage period. Sensory analysis revealed that the MRPPC was useful as a food colorant in yogurt, where it improved color quality without affecting aroma and other characteristics. These results indicate that MRPPC is promising food ingredient as a natural red-purple colorant.

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

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.