Boosting betalain bioaccessibility from prickly pear peel through pulsed electric fields (PEF) and pressurized liquid extraction (PLE)

Abstract

Betalains are bioactive pigments with antioxidant and health-promoting potential, abundant in prickly pear (Opuntia ficus-indica) peel, an underutilized by-product. This study evaluated the efficiency of pulsed electric fields (PEF) and pressurized liquid extraction (PLE) for betalain recovery and their impact on compound bioaccessibility after in vitro digestion. Freeze-dried peels were treated with PEF (2.5 kV/cm, 50 kJ/kg) and PLE (50 °C, 1500 psi, pH 7), and compared to conventional aqueous maceration. Betalains were quantified by UV/Vis and characterized by LC-Q-TOF-MS/MS, while bioaccessibility was assessed using the INFOGEST protocol. PLE increased total betalain yield by 36.3%, whereas PEF enhanced bioaccessibility despite a lower initial concentration. Both techniques preserved 21–22 betalain derivatives, including indicaxanthin and betanin, showing high stability during digestion. These results highlight the potential of PEF and PLE as sustainable technologies for efficient extraction and stabilization of betalains, supporting circular bioeconomy strategies through the valorization of prickly pear peels.