2026-04-28T17:56:04Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/87782024-03-09T01:05:26Zcom_10259_4244com_10259_5086com_10259_2604col_10259_4245

Trigueros Andrés, Ester Benito Román, Oscar Oliveira, Andreia P. Videira, Romeu A. Andrade, Paula B. Sanz Díez, Mª Teresa Beltrán Calvo, Sagrario 2024-03-08T08:01:31Z 2024-03-08T08:01:31Z 2024-02 2076-3921 http://hdl.handle.net/10259/8778 10.3390/antiox13020205 2076-3921 Onion skin waste (OSW), the primary non-edible byproduct from onion processing, offers a renewable source of bioactive compounds. This study aims to valorize OSW through subcritical water extraction (SWE), aligning with a circular economy and biorefinery principles. SWE was carried out at 145 °C and 50 bar for 50 min in a discontinuous reactor, producing a phenolic-rich extract (32.3 ± 2.6 mg/g) dominated by protocatechuic acid (20.3 ± 2.5 mg/g), quercetin-4′-O-glucoside (7.5 ± 0.2 mg/g), and quercetin (3.2 ± 0.6 mg/g). Additionally, the extract contains sugars (207.1 ± 20.3 mg sucrose-Eq/g), proteins (22.8 ± 1.6 mg BSA-Eq/g), and free amino acids (20.4 ± 1.2 mg arginine-Eq/g). Its phenolic richness determines its scavenging activity against ●NO and O2●− radicals and its α-glucosidase and aldose-reductase inhibition without affecting α-amylase. Notably, the extract demonstrates significant α-glucosidase inhibition (IC50 = 75.6 ± 43.5 µg/mL), surpassing acarbose (IC50 = 129.5 ± 1.0 µg/mL) in both pure enzyme and cell culture tests without showing cytotoxicity to AGS, HepG2, and Caco-2 human cell lines. The extract’s bioactivity and nutritional content make it suitable for developing antioxidant and antidiabetic nutraceutical/food components, highlighting SWE’s potential for OSW valorization without using organic solvents. This research was funded by Portuguese national funds (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project UIDP/50006/2020 of REQUIMTE/LAQV, and by the Spanish Agencia Estatal de Investigación [grant number PID2020-116716RJ-I00/AEI/10.13039/501100011033]. application/pdf eng MDPI Antioxidants. 2024, V. 13, n. 2, 205 https://doi.org/10.3390/antiox13020205 info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-116716RJ-I00/ES/TECNOLOGIAS DE FLUIDOS PRESURIZADOS PARA LA VALORIZACION DE SUBPRODUCTOS DE LA INDUSTRIA AGROALIMENTARIA: RECUPERACION DE PECTINA Y OTROS COMPUESTOS BIOACTIVOS DE ALTO VALOR/ Atribución 4.0 Internacional http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Hydrothermal treatment Onion waste Polyphenols Quercetin Antioxidant activity Antidiabetic potential Ingeniería química Chemical engineering Onion (Allium cepa L.) Skin Waste Valorization: Unveiling the Phenolic Profile and Biological Potential for the Creation of Bioactive Agents through Subcritical Water Extraction info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Antioxidants 13 2 205