{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T03:33:15Z","timestamp":1787887995639,"version":"build-2784847793"},"reference-count":41,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:00:00Z","timestamp":1760140800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Yunnan International Joint Laboratory of China-Thailand Avocado Industry Green Development","award":["202403AP140019"],"award-info":[{"award-number":["202403AP140019"]}]},{"name":"Yunnan Provincial Department of Education, Avocado Quality and High-Yield Production Technology Integration and Application Innovation Team","award":["YJF [2024]No.4"],"award-info":[{"award-number":["YJF [2024]No.4"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antioxidants"],"abstract":"<jats:p>This study aimed to develop an environmentally friendly and relatively efficient method for extracting natural antioxidants from avocado by-products while investigating the antioxidant mechanisms of their core bioactive components on multiple dimensions. In vitro antioxidant assays (ABTS, FRAP, SAFR, SFR, ORAC, DPPH) demonstrated that flavonoid procyanidin was the primary antioxidant component in avocado seeds, exhibiting the strongest activity (DPPH EC50 = 3.6 \u00b5g\/mL). The Hill model indicated a positive synergistic effect (n = 3.1). Chemical and molecular mechanism analyses revealed that avocado seeds exert antioxidant activity predominantly through hydrogen atom transfer (HAT) and electron transfer (ET) pathways. The model predictions suggested procyanidins may stably bind to protein targets in the Keap1-Nrf2 pathway and NOX2 via hydrogen bonding, hydrophobic interactions, and \u03c0-cation interactions. Furthermore, response surface methodology (RSM) was employed to optimize the extraction process of avocado seed antioxidants in an ethanol-water system. This study underscores the considerable health benefits and antioxidant capacity of avocado by-products, supporting their promising application in functional foods formulations.<\/jats:p>","DOI":"10.3390\/antiox14101225","type":"journal-article","created":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T08:10:31Z","timestamp":1760343031000},"page":"1225","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Bioactive Antioxidants from Avocado By-Products: Mechanistic Study and Laboratory-Scale Extraction Optimization"],"prefix":"10.3390","volume":"14","author":[{"given":"Ziyao","family":"Xin","sequence":"first","affiliation":[{"name":"School of Chemical Engineering Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yicheng","family":"Gao","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leiyu","family":"He","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1150-658X","authenticated-orcid":false,"given":"Zhilong","family":"Xiu","sequence":"additional","affiliation":[{"name":"School of Bioengineering, Dalian University of Technology, Dalian 116000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lihui","family":"Sun","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Segovia, F.J., Hidalgo, G.I., Villasante, J., Ramis, X., and Almajano, M.P. (2018). Avocado Seed: A Comparative Study of Antioxidant Content and Capacity in Protecting Oil Models from Oxidation. Molecules, 23.","DOI":"10.3390\/molecules23102421"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Rosero, J.C., Cruz, S., Osorio, C., and Hurtado, N. (2019). Analysis of Phenolic Composition of Byproducts (Seeds and Peels) of Avocado (Persea americana Mill.) Cultivated in Colombia. Molecules, 24.","DOI":"10.3390\/molecules24173209"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100275","DOI":"10.1016\/j.afres.2023.100275","article-title":"Avocado production in Kenya in relation to the world, Avocado by-products (seeds and peels) functionality and utilization in food products","volume":"3","author":"Ebere","year":"2023","journal-title":"Appl. Food Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1016\/j.foodchem.2017.12.011","article-title":"Comprehensive identification of bioactive compounds of avocado peel by liquid chromatography coupled to ultra-high-definition accurate-mass Q-TOF","volume":"245","author":"Figueroa","year":"2018","journal-title":"Food Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"81","DOI":"10.21873\/invivo.11748","article-title":"Radical-scavenging and Pro-\/anti-inflammatory Activity of Tetracycline and Related Phenolic Compounds With or Without Visible Light Irradiation","volume":"34","author":"Murakami","year":"2020","journal-title":"In Vivo"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Karim, M.R., Miletti-Gonzalez, K.E., Aryee, A.N.A., and Besong, S.A. (2025). Phytochemical Analysis and Antioxidant Activities of Prunus africana Bark, Leea indica and Paullinia pinnata Leaf Extracts. Antioxidants, 14.","DOI":"10.3390\/antiox14060666"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1189","DOI":"10.1007\/s12161-025-02787-x","article-title":"Optimization Extraction Conditions of Bioactive Compounds of Carum copticum L. Seed by Microwave Using Response Surface Methodology (RSM)","volume":"18","author":"Bazdar","year":"2025","journal-title":"Food Anal. Methods"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Awad, A.M., Kumar, P., Ismail-Fitry, M.R., Jusoh, S., Ab Aziz, M.F., and Sazili, A.Q. (2021). Green Extraction of Bioactive Compounds from Plant Biomass and Their Application in Meat as Natural Antioxidant. Antioxidants, 10.","DOI":"10.3390\/antiox10091465"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"101140","DOI":"10.1016\/j.coche.2025.101140","article-title":"Industrialization of hydrodynamic cavitation in plant resource extraction","volume":"48","author":"Meneguzzo","year":"2025","journal-title":"Curr. Opin. Chem. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"101420","DOI":"10.1016\/j.fochx.2024.101420","article-title":"Modeling and optimization of microwave-assisted extraction of total phenolics content from mango (Mangifera indica) peel using response surface methodology (RSM) and artificial neural networks (ANN)","volume":"22","author":"Quintana","year":"2024","journal-title":"Food Chem. X"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Yue, F., Zhang, J., Xu, J., Niu, T., Lu, X., and Liu, M. (2022). Effects of monosaccharide composition on quantitative analysis of total sugar content by phenol-sulfuric acid method. Front. Nutr., 9.","DOI":"10.3389\/fnut.2022.963318"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"17543","DOI":"10.1021\/acs.jafc.3c04022","article-title":"The Chemistry Behind the Folin-Ciocalteu Method for the Estimation of (Poly)phenol Content in Food: Total Phenolic Intake in a Mediterranean Dietary Pattern","volume":"71","author":"Perez","year":"2023","journal-title":"J. Agric. Food Chem."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Rumpf, J., Burger, R., and Schulze, M. (2023). Statistical evaluation of DPPH, ABTS, FRAP, and Folin-Ciocalteu assays to assess the antioxidant capacity of lignins. Int. J. Biol. Macromol., 233.","DOI":"10.1016\/j.ijbiomac.2023.123470"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Zulkifli, S.A., Abd Gani, S.S., Zaidan, U.H., and Halmi, M.I.E. (2020). Optimization of Total Phenolic and Flavonoid Contents of Defatted Pitaya (Hylocereus polyrhizus) Seed Extract and Its Antioxidant Properties. Molecules, 25.","DOI":"10.3390\/molecules25040787"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"107079","DOI":"10.1016\/j.ultsonch.2024.107079","article-title":"Ultrasound-assisted extraction, optimization, and purification of total flavonoids from Daphnegenkwa and analysis of their antioxidant, anti-inflammatory, and analgesic activities","volume":"111","author":"Xiang","year":"2024","journal-title":"Ultrason. Sonochem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"132185","DOI":"10.1016\/j.molstruc.2021.132185","article-title":"Research on structure and antioxidant activity of polysaccharides from Ginkgo biloba leaves","volume":"1252","author":"Wang","year":"2022","journal-title":"J. Mol. Struct."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1800","DOI":"10.1021\/acs.jafc.7b04509","article-title":"Differential Partitioning of Triterpenes and Triterpene Esters in Apple Peel","volume":"66","author":"Poirier","year":"2018","journal-title":"J. Agric. Food Chem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1007\/s40199-020-00342-z","article-title":"Validated spectrophotometric method for quantification of total triterpenes in plant matrices","volume":"28","author":"Pedrosa","year":"2020","journal-title":"Daru"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3911","DOI":"10.1002\/fsn3.3377","article-title":"Anthocyanin and proanthocyanidin from Aronia melanocarpa (Michx.) Ell.: Purification, fractionation, and enzyme inhibition","volume":"11","author":"Chen","year":"2023","journal-title":"Food Sci. Nutr."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"101678","DOI":"10.1016\/j.fochx.2024.101678","article-title":"Valorization of faba bean peels for fungal tannase production and its application in coffee tannin removal","volume":"23","author":"Mostafa","year":"2024","journal-title":"Food Chem. X"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"111851","DOI":"10.1016\/j.jfoodeng.2023.111851","article-title":"Exergoeconomic analysis of ultrasound-assisted extraction of tannins from acorn fruit","volume":"367","author":"Icier","year":"2024","journal-title":"J. Food Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"140900","DOI":"10.1016\/j.foodchem.2024.140900","article-title":"Phenolic profiles of Australian monofloral Eucalyptus, Corymbia, Macadamia and Lophostemon honeys via HPLC-DAD analysis","volume":"462","author":"Moore","year":"2025","journal-title":"Food Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"113770","DOI":"10.1016\/j.lwt.2022.113770","article-title":"Comprehensive analysis of polyphenols from hybrid Mandarin peels by SPE and HPLC-UV","volume":"165","author":"Anticona","year":"2022","journal-title":"LWT"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"e202402383","DOI":"10.1002\/cssc.202402383","article-title":"Guidelines for Evaluating the Antioxidant Activity of Lignin via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) Assay","volume":"18","author":"Diment","year":"2025","journal-title":"ChemSusChem"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e42223","DOI":"10.1016\/j.heliyon.2025.e42223","article-title":"Influence of fruit stages on chemical compositions, phytochemicals, and antioxidant activity of wood apple (Feronia limonia (L.) Swingle)","volume":"11","author":"Srivastava","year":"2025","journal-title":"Heliyon"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Kim, J., Ryu, J., Lee, S.H., Kim, J.H., Kim, D.G., Ha, T.H., and Kim, S.H. (2025). Evaluation of Anthocyanin Profiling, Total Phenolic and Flavonoid Content, and Antioxidant Activity of Korean Rubus Accessions for Functional Food Applications and Breeding. Antioxidants, 14.","DOI":"10.3390\/antiox14081012"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Yang, H., Liu, Y., Wen, F., Yan, X., Zhang, Y., and Zhong, Z. (2024). Preparation, characterization, antioxidant and antifungal activities of benzoic acid compounds grafted onto chitosan. Int. J. Biol. Macromol., 259.","DOI":"10.1016\/j.ijbiomac.2023.129096"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Wang, X., Yang, Z., Liu, Y., Wang, X., Zhang, H., Shang, R., Laba, C., Wujin, C., Hao, B., and Wang, S. (2022). Structural characteristic of polysaccharide isolated from Nostoc commune, and their potential as radical scavenging and antidiabetic activities. Sci. Rep., 12.","DOI":"10.1038\/s41598-022-26802-x"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Acosta-Quiroga, K., Rocha-Valderrama, E., Zuniga-Bustos, M., Mera-Adasme, R., Cabrera-Barjas, G., Olea-Azar, C., and Moncada-Basualto, M. (2025). Gross Antioxidant Capacity and Anti-Inflammatory Potential of Flavonol Oxidation Products: A Combined Experimental and Theoretical Study. Antioxidants, 14.","DOI":"10.3390\/antiox14040479"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Xiang, J., Huang, S., Wu, X., He, Y., Shen, H., Tang, S., Zhu, F., and Luo, Y. (2025). Phytochemical Profile and Antioxidant Activity of the Tuber and Peel of Pachyrhizus erosus. Antioxidants, 14.","DOI":"10.3390\/antiox14040416"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e2400758","DOI":"10.1002\/ardp.202400758","article-title":"Antioxidant activity, phytochemical composition, and antitumor capacity of Amazonian fruits tapereba (Spondias mombin) and murici (Byrsonima crassifolia)","volume":"358","author":"Lima","year":"2025","journal-title":"Arch. Pharm."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Puscas, A., Tanislav, A.E., Marc, R.A., Muresan, V., Muresan, A.E., Pall, E., and Cerbu, C. (2022). Cytotoxicity Evaluation and Antioxidant Activity of a Novel Drink Based on Roasted Avocado Seed Powder. Plants, 11.","DOI":"10.3390\/plants11081083"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1007\/s11130-021-00900-z","article-title":"Prediction of the Physicochemical and Nutraceutical Characteristics of \u2018Hass\u2019 Avocado Seeds by Correlating the Physicochemical Avocado Fruit Properties According to Their Ripening State","volume":"76","year":"2021","journal-title":"Plant Foods Hum. Nutr."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Salazar-Irrazabal, M.D., Ramirez-Tixe, E.E., Velasquez-Barreto, F.F., and Bello-Perez, L.A. (2023). Avocado seed starch: Effect of the variety on molecular, physicochemical, and digestibility characteristics. Int. J. Biol. Macromol., 247.","DOI":"10.1016\/j.ijbiomac.2023.125746"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1016\/j.foodchem.2019.04.121","article-title":"Chemical composition, nutritional value and bioactive compounds in six uvaia accessions","volume":"294","author":"Spricigo","year":"2019","journal-title":"Food Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"143533","DOI":"10.1016\/j.foodchem.2025.143533","article-title":"Characterization of physicochemical properties, fatty acids, flavor volatiles and phenolic compounds of avocado varieties","volume":"482","author":"Chen","year":"2025","journal-title":"Food Chem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"S28","DOI":"10.1017\/S0007114510003922","article-title":"Fruit polyphenols and CVD risk: A review of human intervention studies","volume":"104","author":"Chong","year":"2010","journal-title":"Br. J. Nutr."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Mejia, J., Giovagnoli-Vicuna, C., Jacob, C., Montenegro, G., Moreno-Switt, A.I., and Giordano, A. (2025). Antioxidant, Antibacterial, and Bioaccessibility Properties of Ultrasound-Extracted Chilean Propolis. Antioxidants, 14.","DOI":"10.3390\/antiox14060651"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Madeswaran, A., and Mohan, S. (2023). Neuroprotective effects of terpenoids against streptozotocin-nicotinamide-induced diabetic rats: An in silico, in vitro and in vivo study. Int. J. Biol. Macromol., 247.","DOI":"10.1016\/j.ijbiomac.2023.125817"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1016\/j.ijbiomac.2019.09.168","article-title":"The antioxidant activities of balsam pear polysaccharide","volume":"142","author":"Mei","year":"2020","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Pozzo, L., Raffaelli, A., Ciccone, L., Zabini, F., Vornoli, A., Calderone, V., Testai, L., and Meneguzzo, F. (2025). Conifer By-Products Extracted Using Hydrodynamic Cavitation as a Convenient Source of Phenolic Compounds and Free Amino Acids with Antioxidant and Antimicrobial Properties. Molecules, 30.","DOI":"10.3390\/molecules30132722"}],"container-title":["Antioxidants"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3921\/14\/10\/1225\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T08:29:05Z","timestamp":1760344145000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3921\/14\/10\/1225"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,11]]},"references-count":41,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2025,10]]}},"alternative-id":["antiox14101225"],"URL":"https:\/\/doi.org\/10.3390\/antiox14101225","relation":{},"ISSN":["2076-3921"],"issn-type":[{"value":"2076-3921","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,11]]}}}