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Background: Betalains are natural red color pigments abundant in red-fleshed dragon fruit (Hylocereus polyrhizus). Recent research has shown that dragon fruit consumption may help improve blood glucose and lipid profile. However, investigations of its cardioprotective properties in human trials, especially in nutritionally achievable amounts, remain nonexistent., Objectives: The aim of this study was to investigate the effects of acute and short-term consumption of dragon fruit on vascular function in a healthy population., Methods: A randomized, double-blind, placebo-controlled, crossover trial was conducted in 19 young, healthy, nonsmoking men and women assigned to consume 24 g whole dragon fruit powder (33 mg betalains) or a nutrient-matched placebo, daily for 14 d. Flow-mediated dilation (FMD), arterial stiffness, and blood pressure (BP) were measured at 0 h, 1 h, 2 h, 3 h, and 4 h and finally at 14 d after daily consumption., Results: A total of 18 participants completed the trial. Dragon fruit consumption significantly improved acute FMD at 2 h (+0.8 ± 0.3%, P = 0.01), 3 h (+1.0 ± 0.3%, P = 0.001), and 4 h (+1.3 ± 0.4%, P < 0.001) postconsumption compared with placebo. This effect was sustained up until 14 d (+1.3 ± 0.2%, P < 0.001). Pulse-wave velocity was acutely significantly reduced at 3 h (-0.5 ± 0.2 m/s, P = 0.003), whereas augmentation index (AIx) also improved after 14 d (-7.0 ± 3.3%, P = 0.02) when compared with placebo. No differences were found in either peripheral or central BP across all time points., Conclusions: Acute and short-term consumption of dragon fruit in dietary achievable amounts improved endothelial function and arterial stiffness in healthy individuals. This implies that regular dragon fruit consumption may have a meaningful impact on cardiovascular disease risk likely due to the high betalain content. This trial was registered at ClinicalTrials.gov as NCT03995602., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Abstract: Betanin is a natural pigment with antioxidant properties used as a food colourant. This work describes the spectrophotometric and chromatographic quantification of betanin (2S/15S) and its epimer isobetanin (2S/15R) in fresh beetroot juice, food-grade beetroot powder and betanin standard diluted in dextrin. Absorption spectra of all three samples were deconvoluted using a mixed three-function model. Food-grade beetroot powder has the largest amount of violet-red impurities, probably formed during processing. The purification of betanin from these complex matrices was carried out by seven different methods. Ion exchange chromatography was the most efficient method for the purification of betanin from all samples; however, fractions contain high amounts of salt. Reversed-phase HPLC as well as reversed-phase column chromatography also produced good results at a much faster rate. The longer retention time of isobetanin when compared to betanin in reversed-phase conditions has been investigated by means of quantum-mechanical methods. [Copyright &y& Elsevier]