Antioxidants (Oct 2023)

Combining Conventional Organic Solvent Extraction, Ultrasound-Assisted Extraction, and Chromatographic Techniques to Obtain Pure Betanin from Beetroot for Clinical Purposes

  • Davi Vieira Teixeira Da Silva,
  • Diego dos Santos Baião,
  • Alviclér Magalhães,
  • Nathan Farias Almeida,
  • Carlos Adam Conte,
  • Vania Margaret Flosi Paschoalin

DOI
https://doi.org/10.3390/antiox12101823
Journal volume & issue
Vol. 12, no. 10
p. 1823

Abstract

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Red beetroot extract (E162) is a natural colorant that owes its color to betanin, its major red pigment. Betanin displays remarkable antioxidant, anti-inflammatory, and chemoprotective properties mediated by its structure and influence on gene expression. However, the betanin employed in most preclinical assays is a beetroot extract diluted in dextrin, not pure betanin, as no isolated compound is commercially available. This makes its use inaccurate concerning product content estimates and biological effect assessments. Herein, a combination of conventional extraction under orbital shaking and ultrasound-assisted extraction (UAE) to purify betanin by semi-preparative HPLC was performed. The employed methodology extracts betalains at over a 90% yield, achieving 1.74 ± 0.01 mg of pure betanin/g beetroot, a 41% yield from beetroot contents increasing to 50 %, considering the betalains pool. The purified betanin exhibited an 85% purity degree against 32 or 72% of a commercial standard evaluated by LC-MS or HPLC methods, respectively. The identity of purified betanin was confirmed by UV-Vis, LC-MS, and 1H NMR. The combination of a conventional extraction, UAE, and semi-preparative HPLC allowed for betanin purification with a high yield, superior purity, and almost three times more antioxidant power compared to commercial betanin, being, therefore, more suitable for clinical purposes.

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