Mechanistic Insights into the Extraction and Stabilization of Betalains and Phenolic Compounds from Beetroot

Beetroot (Beta vulgaris L.) has gained significant attention as a functional food due to its high content of bioactive compounds, including betalains, phenolic acids, flavonoids, and nitrates, which contribute to antioxidant, anti-inflammatory, and cardioprotective effects. Despite their health potential, these compounds face significant challenges due to chemical instability and poor bioavailability, exacerbated by environmental and physiological factors such as light, temperature, pH, and digestive degradation. Recent advances in extraction science have focused on optimizing yield, selectivity, and compound stability through innovative and environmentally friendly approaches. Techniques such as ultrasound-assisted (Table 2), microwave-assisted (Table 3), enzyme-assisted, and pressurized liquid extraction have demonstrated improved efficiency and reduced solvent usage compared to conventional methods. Furthermore, the use of green solvents such as deep eutectic solvent systems has shown remarkable potential for selectively extracting and stabilizing betalains and phenolics. Emerging encapsulation technologies, such as nanoemulsions, polymeric nanoparticles, and cyclodextrin inclusion complexes, further enhance bioavailability by protecting beetroot bioactives during digestion and promoting controlled release. This review provides a critical synthesis of these technological developments, emphasizing the relationship between extraction efficiency, compound stability, and biological accessibility. It also highlights remaining challenges and perspectives for translating laboratory-scale innovations into industrial applications to support the development of stable, bioavailable, and sustainable beetroot-based nutraceuticals and functional foods.

Keywords: Beetroots, Betalains, Bioavailability, Green Extraction, Nutraceuticals, Stability.