Green Extraction of Bioactive Compounds from Sweet Potato (Ipomoea batatas L.) Peels and Comparative In Vitro and Biological Model Antioxidant Evaluation

Abstract This study evaluated the antioxidant potential of orange sweet potato ( Ipomoea batatas L. ) peel extracts obtained through green extraction technologies—pulsed electric fields (PEFs) and pressurized liquid extraction (PLE)—using Saccharomyces cerevisiae BY4741 as a yeast-based biological model for oxidative stress. Conventional maceration was used as a control, and in vitro antioxidant capacity was determined by ABTS, ORAC, FRAP, and DPPH assays. The composition of the extracts was analyzed by spectrophotometry and LC–MS/MS. Compared with maceration, both technologies significantly enhanced antioxidant recovery. PEF–water extracts reached 1.79 µM Trolox equivalents/g in the FRAP assay versus 0.54 µM/g for maceration, while PLE–ethanol achieved 6.30 µM/g (ABTS) and 16,782.8 µM/g (ORAC), showing the highest antioxidant capacity. A consistent relationship was observed between in vitro results and the biological yeast model, confirming that chemical and cellular assays followed a parallel trend in antioxidant response. Under oxidative stress (0.5 and 4 mM H 2 O 2 ), PLE–5 μL of the preculture was inoculated into each flask to achieve an initial OD 600 of 0.005 ± 0.001, followed by incubation at 28 °C with shaking at 190 rpm for 18 h. After incubation, the cultures were centrifuged at 3000 rpm and 20 °C for 10 min, washed with phosphate-buffered saline (PBS, pH 7.4), and adjusted to a final OD 600 of 0.1. Ethanol extracts were effective at 1 and 10 mg GAE/mL, respectively, whereas PEF–water extracts required 10 and 20 mg GAE/mL to achieve comparable protection. These findings demonstrate that orange sweet potato peels are a valuable source of phenolic antioxidants and that PEF and PLE represent eco-efficient alternatives to conventional extraction, offering reduced solvent use and energy demand. The observed agreement between in vitro and biological model assays highlights their potential for identifying predictive in vitro methods and supports the functional application of these extracts in sustainable food and pharmaceutical formulations.