BIOACTIVITY POTENTIAL OF YACON LEAVES EXTRACTS PRODUCED BY PRESSURIZED LIQUID EXTRACTION UNDER DIFFERENT SOLVENT AND TEMPERATURE CONDITION

Yacon (Smallanthus sonchifolius) leaves are a promising source of bioactive compounds with potential applications in food, pharmaceutical, and cosmetic industries. This study aimed to identify an eco-friendly extraction process to maximize bioactive compound recovery from yacon leaves. Pressurized Liquid Extraction (PLE) was applied to dried and milled leaves, with experimental variables including temperature (60, 90, and 120 °C) and solvent concentration (ethanol 25%, 50%, 75%, and 100%), alongside tests using water and subcritical water (110, 130, and 150 °C). The study aimed to maximize global yield and phenolic content. Extracts were evaluated for antioxidant capacity using Oxygen Radical Absorbance Capacity (ORAC) and Ferric Reducing Ability of Plasma (FRAP) assays, protein content through the Bradford method, anti-inflammatory activity via the egg albumin assay, and antimicrobial activity against Lactococcus lactis using agar diffusion. Phenolic compounds were identified by ultra-performance liquid chromatography (UPLC) coupled with photodiode array and mass spectrometry, quantified as caffeic acid equivalents. PLE outperformed the conventional Soxhlet method, with higher temperatures and lower ethanol concentrations yielding enhanced antioxidant capacity in both ORAC and FRAP assays. A strong positive correlation between total phenolic content and antioxidant capacity was observed. Five extraction conditions (ethanol 25% at 60 ºC and 90 ºC; ethanol 50% at 60 °C, 90 ºC, and 120 °C) demonstrated anti-inflammatory activity. Protein content ranged from 5.20 to 43.26 mg BSA/g dry matter for ethanol 100% at 60 ºC and ethanol 50% at 120 ºC, respectively. No antimicrobial activity was detected at the tested concentrations. Chromatographic analysis identified key phenolics, such as caffeic acid, glucaric acid, quercetin-O-hexoside, and kaempferol-O-hydroxylferuloyl derivatives, highlighting the presence of well-known antioxidant compounds. These results demonstrate the potential of yacon leaves to provide valuable bioactive compounds and confirm the feasibility of using eco-friendly PLE technology for their extraction.