{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T18:08:03Z","timestamp":1785434883626,"version":"3.56.0"},"reference-count":47,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"City of Plock"},{"DOI":"10.13039\/501100004421","name":"Warsaw University of Technology","doi-asserted-by":"crossref","award":["IChem-2025"],"award-info":[{"award-number":["IChem-2025"]}],"id":[{"id":"10.13039\/501100004421","id-type":"DOI","asserted-by":"crossref"}]},{"award":["IChem-2025"],"award-info":[{"award-number":["IChem-2025"]}],"id":[{"id":"https:\/\/ror.org\/00y0xnp53","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The limited oxidative stability of fatty acid methyl esters (FAME) constrains their use as biofuels. This study presents a direct, side-by-side comparison of \u03b2-carotene and \u03b1-tocopherol as natural antioxidant additives in FAME produced from refined rapeseed oil, evaluated under identical thermo-oxidative conditions (100\u2013140 \u00b0C). We combine kinetic modelling (first-order and zero-order fits, Arrhenius analysis) with spectroscopic monitoring (UV\u2013Vis for \u03b2-carotene; FT-IR for \u03b1-tocopherol) and standard oxidation indices (PV, AnV) to link antioxidant depletion to fuel oxidation. Key findings are: (1) \u03b2-carotene effectively delays hydroperoxide formation at lower temperatures but degrades rapidly above 120 \u00b0C (Ea 6\u201323 kJ\u00b7mol\u22121), producing secondary products that increase AnV; (2) \u03b1-tocopherol shows greater thermal resistance and predictable, dose-dependent protection across the tested range (optimal at 556 \u00b5g\u00b7mL\u22121), with higher doses exhibiting potential pro-oxidant effects; (3) activation energies and kinetic orders differ between antioxidants, indicating distinct degradation pathways in the FAME matrix. These results demonstrate that reintroducing natural antioxidants removed during refining can improve biodiesel durability, and that antioxidant selection and dosing must be tailored to expected thermal exposure. The combined kinetic\u2013spectroscopic approach provides a practical framework for optimizing natural additive strategies in biodiesel formulations.<\/jats:p>","DOI":"10.3390\/molecules31132298","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T10:41:01Z","timestamp":1782902461000},"page":"2298","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Kinetic and Spectroscopic Evaluation of \u03b2-Carotene and \u03b1-Tocopherol Degradation in Fatty Acid Methyl Esters"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8918-4624","authenticated-orcid":false,"given":"Pawe\u0142","family":"Grabowski","sequence":"first","affiliation":[{"name":"Faculty of Civil Engineering, Mechanics and Petrochemistry, Warsaw University of Technology, Lukasiewicz Street 17, 09-400 Plock, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angelika","family":"Szwarczy\u0144ska","sequence":"additional","affiliation":[{"name":"Faculty of Civil Engineering, Mechanics and Petrochemistry, Warsaw University of Technology, Lukasiewicz Street 17, 09-400 Plock, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Szymon","family":"Skorupski","sequence":"additional","affiliation":[{"name":"Faculty of Civil Engineering, Mechanics and Petrochemistry, Warsaw University of Technology, Lukasiewicz Street 17, 09-400 Plock, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,1]]},"reference":[{"key":"#cr-split#-ref_1.1","unstructured":"European Parliament and Council (2018). Directive"},{"key":"#cr-split#-ref_1.2","unstructured":"(EU) 2018\/2001 on the Promotion of the Use of Energy from Renewable Sources (RED II). Off. J. Eur. Union, L328, 82-209."},{"key":"ref_2","unstructured":"European Parliament and Council (2023). Directive (EU) 2023\/2413 amending Directive (EU) 2018\/2001, Regulation (EU) 2018\/1999 and Directive 98\/70\/EC as regards the promotion of energy from renewable sources, and repealing Council Directive (EU) 2015\/652 (RED III). Off. J. Eur. Union, L, 2023\/2413."},{"key":"ref_3","unstructured":"(2019). Liquid Petroleum Products\u2014Fatty Acid Methyl Esters (FAME) for Use in Diesel Engines and Heating Applications\u2014Requirements and Test Methods (Standard No. EN 14214)."},{"key":"ref_4","unstructured":"European Parliament and Council (2009). Directive 2009\/30\/EC amending Directive 98\/70\/EC relating to the quality of petrol and diesel fuels (Fuel Quality Directive). Off. J. Eur. Union, L140, 88\u2013113."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1059","DOI":"10.1016\/j.fuproc.2004.11.002","article-title":"Dependence of biodiesel fuel properties on the structure of fatty acid alkyl esters","volume":"86","author":"Knothe","year":"2005","journal-title":"Fuel Process. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1016\/j.biortech.2008.06.039","article-title":"Influence of fatty acid composition of raw materials on biodiesel properties","volume":"100","author":"Ramos","year":"2009","journal-title":"Bioresour. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/j.rser.2012.10.013","article-title":"Non-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, characteristics, engine performance and emissions production","volume":"18","author":"Atabani","year":"2013","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1007\/s11746-003-0778-x","article-title":"The influence of antioxidants on the oxidation stability of biodiesel","volume":"80","author":"Mittelbach","year":"2003","journal-title":"J. Am. Oil Chem. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1016\/j.rser.2009.10.011","article-title":"Oxidation Stability of Biodiesel and Its Blends: A Review","volume":"14","author":"Jain","year":"2010","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"669","DOI":"10.1016\/j.fuproc.2007.01.005","article-title":"Some aspects of biodiesel oxidative stability","volume":"88","author":"Knothe","year":"2007","journal-title":"Fuel Process. Technol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1021\/ef700412c","article-title":"Effect of Temperature on the Oil Stability Index (OSI) of Biodiesel","volume":"22","author":"Dunn","year":"2007","journal-title":"Energy Fuels"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2596","DOI":"10.1016\/j.fuel.2007.02.014","article-title":"Long storage stability of biodiesel from vegetable and used frying oils","volume":"86","author":"Bouaid","year":"2007","journal-title":"Fuel"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1016\/j.fuel.2011.11.061","article-title":"The effect of synthetic antioxidants on the oxidative stability of biodiesel","volume":"94","author":"Focke","year":"2012","journal-title":"Fuel"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2017","DOI":"10.1016\/j.rser.2017.07.020","article-title":"Screening of antioxidant additives for biodiesel fuels","volume":"82","author":"Varatharajan","year":"2018","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1016\/j.rser.2010.08.022","article-title":"Thermal stability of biodiesel and its blends: A review","volume":"15","author":"Jain","year":"2011","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1007\/BF02522884","article-title":"The chemistry and antioxidant properties of tocopherols and tocotrienols","volume":"31","author":"Appelqvist","year":"1996","journal-title":"Lipids"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1145","DOI":"10.1096\/fasebj.13.10.1145","article-title":"Vitamin E: Function and metabolism","volume":"13","author":"Traber","year":"1999","journal-title":"FASEB J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"4067","DOI":"10.1039\/b922183m","article-title":"Lipid oxidation and improving the oxidative stability","volume":"39","author":"Shahidi","year":"2010","journal-title":"Chem. Soc. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1551","DOI":"10.1096\/fasebj.9.15.8529834","article-title":"Structure and properties of carotenoids in relation to function","volume":"9","author":"Britton","year":"1995","journal-title":"FASEB J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1016\/S0098-2997(03)00030-X","article-title":"Antioxidant Activity of Carotenoids","volume":"24","author":"Stahl","year":"2003","journal-title":"Mol. Asp. Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1111\/j.1541-4337.2006.00009.x","article-title":"Mechanisms and Factors for Edible Oil Oxidation","volume":"5","author":"Choe","year":"2006","journal-title":"Compr. Rev. Food Sci. Food Saf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1007\/s11746-001-0306-z","article-title":"Long storage stability of biodiesel made from rapeseed and used frying oil","volume":"78","author":"Mittelbach","year":"2001","journal-title":"J. Am. Oil Chem. Soc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1016\/j.fuel.2014.06.007","article-title":"Use of natural antioxidants in soybean biodiesel","volume":"134","year":"2014","journal-title":"Fuel"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2028","DOI":"10.1021\/ef9012032","article-title":"Effect of Antioxidants on the Storage Stability of Soybean-Oil-Based Biodiesel","volume":"24","author":"Tang","year":"2009","journal-title":"Energy Fuels"},{"key":"ref_25","unstructured":"Rodriguez-Amaya, D.B., and Kimura, M. (2004). HarvestPlus Handbook for Carotenoid Analysis, HarvestPlus, IFPRI."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1080\/10408390802565889","article-title":"Factors Influencing the Chemical Stability of Carotenoids in Foods","volume":"50","author":"Boon","year":"2010","journal-title":"Crit. Rev. Food Sci. Nutr."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1039\/B917636E","article-title":"Carotenoids can act as antioxidants by oxidizing the superoxideradical anion","volume":"12","author":"Galano","year":"2009","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"960","DOI":"10.1021\/jf1040977","article-title":"Synergistic, Additive, and Antagonistic Effects of Food Mixtures on Total Antioxidant Capacities","volume":"59","author":"Wang","year":"2011","journal-title":"J. Agric. Food Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"110006","DOI":"10.1016\/j.jfoodeng.2020.110006","article-title":"The use of natural antioxidants to combat lipid oxidation in O\/W emulsions","volume":"281","author":"Noon","year":"2020","journal-title":"J. Food Eng."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1111\/j.1541-4337.2009.00085.x","article-title":"Mechanisms of Antioxidants in the Oxidation of Foods","volume":"8","author":"Choe","year":"2009","journal-title":"Compr. Rev. Food Sci. Food Saf."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"10907","DOI":"10.1016\/j.biortech.2011.09.068","article-title":"Study of biodiesel production from animal fats with high free fatty acid content","volume":"102","author":"Encinar","year":"2011","journal-title":"Bioresour. Technol."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Kamal-Eldin, A. (2003). Lipid Oxidation Pathways, AOCS Press.","DOI":"10.1201\/9781003040316"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Akoh, C.C. (2017). Rethinking lipid oxidation. Food Lipids Chemistry, Nutrition, and Biotechnology, CRC Press, Taylor & Francis Group. [4th ed.].","DOI":"10.1201\/9781315151854-27"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1071","DOI":"10.1016\/j.fuproc.2004.11.003","article-title":"Effect of antioxidants on the oxidative stability of methyl soyate (biodiesel)","volume":"86","author":"Dunn","year":"2005","journal-title":"Fuel Process. Technol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Lavelli, V., and Sereikait\u0117, J. (2022). Kinetic Study of Encapsulated \u03b2-Carotene Degradation in Aqueous Environments: A Review. Foods, 11.","DOI":"10.3390\/foods11030317"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1051\/fruits\/2011058","article-title":"Degradation of \u03b2-carotene during fruit and vegetable processing or storage: Reaction mechanisms and kinetic aspects: A review","volume":"66","author":"Achir","year":"2011","journal-title":"Fruits"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1095","DOI":"10.1111\/j.1365-2621.1997.tb12235.x","article-title":"Comparison of Spray-drying, Drum-dryingand Freeze-drying for b-CaroteneEncapsulation and Preservation","volume":"62","author":"Desobry","year":"1997","journal-title":"J. Food Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"111109","DOI":"10.1016\/j.rser.2021.111109","article-title":"A comprehensive review of the selection of natural and synthetic antioxidants to enhance the oxidative stability of biodiesel","volume":"145","author":"Romola","year":"2021","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1016\/j.foodchem.2004.05.059","article-title":"Determining \u03b1-tocopherol in refined bleached and deodorized palm olein by Fourier transform infrared spectroscopy","volume":"90","author":"Man","year":"2005","journal-title":"Food Chem."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Grabowski, P., and Szwarczy\u0144ska, A. (2024). Non-Normative Oxidation Stability Indication of FAME Produced from Rapeseed and Used Cooking Oil. Energies, 17.","DOI":"10.3390\/en17174210"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1080\/17597269.2024.2447153","article-title":"Anisidine value as oxidation stability indicator in FAME","volume":"16","author":"Grabowski","year":"2024","journal-title":"Biofuels"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Wili\u0144ska, I., Grabowski, P., S\u0142o\u0144ski, M., and Koc, M. (2026). The Influence of Raw Materials for Fatty Acid Methyl Ester Production on the Aging Rate of Diesel Fuel Blends with Biocomponents. Energies, 19.","DOI":"10.3390\/en19102251"},{"key":"ref_43","unstructured":"(2017). Animal and Vegetable Fats and Oils\u2014Determination of Peroxide Value\u2014Iodometric (Visual) Endpoint Determination (Standard No. EN ISO 3960)."},{"key":"ref_44","unstructured":"(2016). Animal and Vegetable Fats and Oils\u2014Determination of Anisidine Value (Standard No. EN ISO 6885)."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"128481","DOI":"10.1016\/j.foodchem.2020.128481","article-title":"A fast and simple method for determination of \u03b2-carotene in commercial fruit juice by cloud point extraction-cold column trapping combined with UV\u2013Vis spectrophotometry","volume":"343","author":"Safdarian","year":"2021","journal-title":"Food Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1007\/s12161-008-9047-y","article-title":"Rapid Determination of \u03b1-Tocopherol in Vegetable Oils by Fourier Transform Infrared Spectroscopy","volume":"2","author":"Silva","year":"2008","journal-title":"Food Anal. 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