Determination and comparison of triacylglycerol composition of tea (Camellia sinensis) oil and extra virgin olive oil using 1H NMR and UV–Visible spectroscopy

Determination and comparison of triacylglycerol composition of tea (Camellia sinensis) oil and extra virgin olive oil using 1H NMR and UV–Visible spectroscopy | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Determination and comparison of triacylglycerol composition of tea (Camellia sinensis) oil and extra virgin olive oil using 1H NMR and UV–Visible spectroscopy Hagos Hagos, Girma Workeneh Woyessa, Amitabha Datta This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8707273/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract The authentication and quality assessment of edible oils remain essential due to increasing cases of adulteration and the strong dependence of oil quality on origin, processing, and storage. Tea seed oil and extra virgin olive oil are particularly valued for their high nutritional and medicinal benefits, yet both contain very low levels of ω-3 triunsaturated fatty acids, making accurate quantification analytically challenging. In this study, we establish a simple and reliable quantitative approach for determining the triacylglycerol (TAG) profiles of tea seed oil and extra virgin olive oil using high-resolution 1 H NMR (800 MHz), supported by UV–Visible spectroscopy. The enhanced magnetic field strength allowed us to resolve the bisallylic proton signals at δ 2.69–2.77 ppm, enabling direct and precise calculation of linoleic (ω-6), linolenic (ω-3), and oleic (ω-9) acyl groups through a modified integration method. The TAG composition of tea oil was determined to be 74.83% (ω-9) monounsaturated, 10.14% (ω-6) diunsaturated, 0.38% (ω-3) triunsaturated, and 14.65% saturated fatty acids. In comparison, extra virgin olive oil contained 81.06% (ω-9) monounsaturated, 4.14% (ω-6) diunsaturated, 0.26% (ω-3) triunsaturated, and 14.54% saturated acyl groups. Both oils are therefore predominantly composed of (ω-9) monounsaturated TAGs. High-resolution 1 H NMR (800 MHz) spectra of both oils resolved all known characteristic signals of edible oils, along with two additional signals. These findings indicate that low concentrations of ω-3 triunsaturated acyl groups can be rapidly and accurately quantified by 1 H NMR, owing to the resolved bisallylic hydrogen signals at δ 2.69–2.77 ppm, which enable the use of a modified equation for TAG calculation. The TAG profiles of tea oil closely match those of extra virgin olive oil observed here and reported in the literature. Furthermore, UV–Visible absorption spectra measured for six different commercial edible oil samples support these results. Consistent NMR findings, the spectral pattern and intensity of tea oil closely resemble those of high-quality extra virgin olive oil, based on measurements of 1% (v/v) solutions in hexane. Tea oil Extra virgin olive oil NMR & UV-Vis spectra Linolenic Triacylglycerides Full Text Additional Declarations No competing interests reported. Supplementary Files ESI11.01.2026.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 11 May, 2026 Reviewers agreed at journal 07 May, 2026 Reviewers invited by journal 07 May, 2026 Editor assigned by journal 27 Feb, 2026 Submission checks completed at journal 28 Jan, 2026 First submitted to journal 27 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8707273","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":637892240,"identity":"7617a860-e6e1-402a-8e19-f99e90742d43","order_by":0,"name":"Hagos Hagos","email":"","orcid":"","institution":"Academia Sinica","correspondingAuthor":false,"prefix":"","firstName":"Hagos","middleName":"","lastName":"Hagos","suffix":""},{"id":637892241,"identity":"92dfffad-1ad5-4213-9ee1-359b1b158c19","order_by":1,"name":"Girma Workeneh Woyessa","email":"","orcid":"","institution":"Academia Sinica","correspondingAuthor":false,"prefix":"","firstName":"Girma","middleName":"Workeneh","lastName":"Woyessa","suffix":""},{"id":637892242,"identity":"64c50778-e9db-44ef-9fb0-9fbb6f0b049e","order_by":2,"name":"Amitabha Datta","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3ElEQVRIiWNgGAWjYFACxgYGHgY2Bn4GIAEXIaClsQGkRbKBeC1AFTxA0uAAXAsBwD/tcPuDNwx8iZtvJD978KGCQZ6fgbntAT4tErcTGxvnMLAlbruRZm444wyD4cwGxnYDvNYAtTTzgLUkmEnztjEkGBxgbJPAp0MepmXzjPRvxGkxgGnZIJFDpC2GQC0zgX4xnnHmTZnkjDMShjObCWiRu53+4MMbhmOy/e3p2yQ+VNjI87O3P8OrBQwY/x1jYBBIADGBipkJqgeDGmAMHSBO6SgYBaNgFIw8AAAusUc0N4o7xgAAAABJRU5ErkJggg==","orcid":"","institution":"National Changhua University of Education","correspondingAuthor":true,"prefix":"","firstName":"Amitabha","middleName":"","lastName":"Datta","suffix":""}],"badges":[],"createdAt":"2026-01-27 07:40:44","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8707273/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8707273/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109340007,"identity":"0c481419-ebc0-4085-a152-798261be1e0a","added_by":"auto","created_at":"2026-05-15 18:26:19","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":699336,"visible":true,"origin":"","legend":"","description":"","filename":"TeaOilManuscript12.01.2026.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8707273/v1_covered_024dc00d-95de-43a0-a9e4-0d45f51f18de.pdf"},{"id":109340005,"identity":"446f9148-85aa-4554-b2cd-542204225d0b","added_by":"auto","created_at":"2026-05-15 18:26:14","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":163916,"visible":true,"origin":"","legend":"","description":"","filename":"ESI11.01.2026.docx","url":"https://assets-eu.researchsquare.com/files/rs-8707273/v1/f3c4e6b863c563df2ab1a6ec.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Determination and comparison of triacylglycerol composition of tea (Camellia sinensis) oil and extra virgin olive oil using 1H NMR and UV–Visible spectroscopy","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-proteins-and-proteomics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Journal of Proteins and Proteomics](https://www.springer.com/journal/42485)","snPcode":"42485","submissionUrl":"https://submission.nature.com/new-submission/42485/3","title":"Journal of Proteins and Proteomics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Tea oil, Extra virgin olive oil, NMR \u0026 UV-Vis spectra, Linolenic, Triacylglycerides","lastPublishedDoi":"10.21203/rs.3.rs-8707273/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8707273/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe authentication and quality assessment of edible oils remain essential due to increasing cases of adulteration and the strong dependence of oil quality on origin, processing, and storage. Tea seed oil and extra virgin olive oil are particularly valued for their high nutritional and medicinal benefits, yet both contain very low levels of ω-3 triunsaturated fatty acids, making accurate quantification analytically challenging. In this study, we establish a simple and reliable quantitative approach for determining the triacylglycerol (TAG) profiles of tea seed oil and extra virgin olive oil using high-resolution \u003csup\u003e1\u003c/sup\u003eH NMR (800 MHz), supported by UV\u0026ndash;Visible spectroscopy. The enhanced magnetic field strength allowed us to resolve the bisallylic proton signals at δ 2.69\u0026ndash;2.77 ppm, enabling direct and precise calculation of linoleic (ω-6), linolenic (ω-3), and oleic (ω-9) acyl groups through a modified integration method. The TAG composition of tea oil was determined to be 74.83% (ω-9) monounsaturated, 10.14% (ω-6) diunsaturated, 0.38% (ω-3) triunsaturated, and 14.65% saturated fatty acids. In comparison, extra virgin olive oil contained 81.06% (ω-9) monounsaturated, 4.14% (ω-6) diunsaturated, 0.26% (ω-3) triunsaturated, and 14.54% saturated acyl groups. Both oils are therefore predominantly composed of (ω-9) monounsaturated TAGs. High-resolution \u003csup\u003e1\u003c/sup\u003eH NMR (800 MHz) spectra of both oils resolved all known characteristic signals of edible oils, along with two additional signals. These findings indicate that low concentrations of ω-3 triunsaturated acyl groups can be rapidly and accurately quantified by \u003csup\u003e1\u003c/sup\u003eH NMR, owing to the resolved bisallylic hydrogen signals at δ 2.69\u0026ndash;2.77 ppm, which enable the use of a modified equation for TAG calculation. The TAG profiles of tea oil closely match those of extra virgin olive oil observed here and reported in the literature. Furthermore, UV\u0026ndash;Visible absorption spectra measured for six different commercial edible oil samples support these results. Consistent NMR findings, the spectral pattern and intensity of tea oil closely resemble those of high-quality extra virgin olive oil, based on measurements of 1% (v/v) solutions in hexane.\u003c/p\u003e","manuscriptTitle":"Determination and comparison of triacylglycerol composition of tea (Camellia sinensis) oil and extra virgin olive oil using 1H NMR and UV–Visible spectroscopy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-15 18:26:10","doi":"10.21203/rs.3.rs-8707273/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"153445647139520441620788695807547908226","date":"2026-05-11T04:38:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"138296183918577464707433806462567939779","date":"2026-05-07T13:16:56+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-07T07:14:54+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-27T09:32:44+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-28T07:24:19+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Proteins and Proteomics","date":"2026-01-27T07:22:26+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-proteins-and-proteomics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Journal of Proteins and Proteomics](https://www.springer.com/journal/42485)","snPcode":"42485","submissionUrl":"https://submission.nature.com/new-submission/42485/3","title":"Journal of Proteins and Proteomics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"aa74ca5f-e10d-44ed-ae88-50be6ad5acbb","owner":[],"postedDate":"May 15th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"153445647139520441620788695807547908226","date":"2026-05-11T04:38:01+00:00","index":9,"fulltext":""},{"type":"reviewerAgreed","content":"138296183918577464707433806462567939779","date":"2026-05-07T13:16:56+00:00","index":8,"fulltext":""},{"type":"reviewersInvited","content":"2","date":"2026-05-07T07:14:54+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-15T18:26:11+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-15 18:26:10","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8707273","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8707273","identity":"rs-8707273","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}