{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T15:06:52Z","timestamp":1789398412736,"version":"build-2803163510"},"reference-count":20,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T00:00:00Z","timestamp":1789344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004410","name":"The Scientific and Technological Research Council of T\u00fcrkiye","doi-asserted-by":"publisher","award":["123O889"],"award-info":[{"award-number":["123O889"]}],"id":[{"id":"10.13039\/501100004410","id-type":"DOI","asserted-by":"publisher"}]},{"award":["123O889"],"award-info":[{"award-number":["123O889"]}],"id":[{"id":"https:\/\/ror.org\/04w9kkr77","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Foods"],"abstract":"<jats:p>Commercial aromatic herbs sold under the names thyme and oregano may encompass heterogeneous plant materials, making chemical-profile screening important even when botanical identity is unknown. This study characterized 110 commercial products marketed in T\u00fcrkiye and evaluated whether portable near-infrared (NIR) spectroscopy could predict chemical-profile classes derived independently from GC-FID\/MS data. Commercial labels were recorded but were not treated as verified species identities. Essential oils were measured in technical duplicate for 23 volatile compounds; replicate means were subjected to compositional data treatment, principal component analysis and Ward clustering. Two clusters were selected by the silhouette criterion (0.485), and cluster stability under technical-replicate resampling was high (median adjusted Rand index, 0.907). Cluster 1 (n = 17) was relatively enriched in sabinene, caryophyllene, carvacrol and delta-3-carene, whereas Cluster 2 (n = 93) showed higher myrcene, p-cymene, alpha-pinene and beta-pinene. Two NIR spectra were collected per sample. To prevent replicate leakage, spectra were averaged before repeated nested cross-validation; a grouped-replicate analysis was also performed. A majority-class baseline achieved 84.55% accuracy but only 0.500 balanced accuracy. The best primary model, shrinkage linear discriminant analysis, yielded a mean accuracy of 0.689, a balanced accuracy of 0.565, a macro-F1 of 0.530 and a Matthews correlation coefficient of 0.103. The grouped-replicate sensitivity analysis gave a balanced accuracy of 0.592. Thus, GC-FID\/MS revealed a stable chemical-profile structure, but portable NIR did not reliably recover the minority chemical class. NIR may support exploratory triage after broader calibration, but the present data do not support stand-alone botanical authentication or definitive chemical-class assignment.<\/jats:p>","DOI":"10.3390\/foods15183245","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T14:15:04Z","timestamp":1789395304000},"page":"3245","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["GC-Derived Volatile Profiling of Commercial Thyme and Oregano Labeled Products and Evaluation of Portable NIR Screening"],"prefix":"10.3390","volume":"15","author":[{"given":"Necla","family":"Ozdemir-Orhan","sequence":"first","affiliation":[{"name":"Department of Nutrition and Dietetics, Faculty of Health Sciences, Bitlis Eren University, Bitlis 13100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Merve","family":"Akpinar-Uzun","sequence":"additional","affiliation":[{"name":"Department of Food Engineering, Faculty of Engineering, Ankara University, Ankara 06830, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4163-8679","authenticated-orcid":false,"given":"Nurhan","family":"Gunes","sequence":"additional","affiliation":[{"name":"Department of Electric-Electronic Engineering, Faculty of Engineering, Sivas University of Science and Technology, Sivas 58100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"software","vocabulary":"credit"}]},{"given":"Aziz","family":"Tekin","sequence":"additional","affiliation":[{"name":"Department of Food Engineering, Faculty of Engineering, Ankara University, Ankara 06830, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2454-7898","authenticated-orcid":false,"given":"Ahmed","family":"Menevseoglu","sequence":"additional","affiliation":[{"name":"Department of Gastronomy and Culinary Arts, School of Tourism and Hotel Management, Agri Ibrahim Cecen University, Agri 04100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"228","DOI":"10.3390\/agriculture2030228","article-title":"Aromatic plants as a source of bioactive compounds","volume":"2","author":"Christaki","year":"2012","journal-title":"Agriculture"},{"key":"ref_2","first-page":"583","article-title":"T\u00fcrkiye\u2019de yetisen kekik t\u00fcrleri, ekonomik \u00f6nemi ve kullanim alanlari","volume":"29","author":"Bozdemir","year":"2019","journal-title":"Yuz. Y\u0131l Univ. J. Agric. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"820","DOI":"10.1007\/s11694-017-9696-x","article-title":"Effect of different drying methods on the essential oil yield, composition and antioxidant activity of Origanum vulgare L. and Origanum onites L","volume":"12","author":"Ozdemir","year":"2018","journal-title":"J. Food Meas. Charact."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1111\/j.2517-6161.1982.tb01195.x","article-title":"The statistical analysis of compositional data","volume":"44","author":"Aitchison","year":"1982","journal-title":"J. R. Stat. Soc. Ser. B"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"105672","DOI":"10.1016\/j.jfca.2023.105672","article-title":"Oregano herb adulteration detection through rapid spectroscopic approaches: Fourier transform-near infrared and laser photoacoustic spectroscopy facilities","volume":"124","author":"Sammarco","year":"2023","journal-title":"J. Food Compos. Anal."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"106637","DOI":"10.1016\/j.jfca.2024.106637","article-title":"Chemometrics coupled with near infrared spectroscopy for detecting adulteration levels in herbal teas","volume":"135","year":"2024","journal-title":"J. Food Compos. Anal."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"109949","DOI":"10.1016\/j.microc.2024.109949","article-title":"Rapid and non-destructive quality estimation of cinchona, Andrographis paniculata, and black pepper using a portable NIR spectroscopy measuring device","volume":"199","author":"Sing","year":"2024","journal-title":"Microchem. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"107538","DOI":"10.1016\/j.jfca.2025.107538","article-title":"Chemometric-based approach for economically motivated fraud detection in organic spices via NIR spectroscopy","volume":"142","author":"Schumer","year":"2025","journal-title":"J. Food Compos. Anal."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Chen, R., Liu, F., Zhang, C., Wang, W., Yang, R., Zhao, Y., Peng, J., Kong, W., and Huang, J. (2023). Trends in digital detection for the quality and safety of herbs using infrared and Raman spectroscopy. Front. Plant Sci., 14.","DOI":"10.3389\/fpls.2023.1128300"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"104522","DOI":"10.1016\/j.tifs.2024.104522","article-title":"Spice authentication by near-infrared spectroscopy: Current advances, limitations, and future perspectives","volume":"148","author":"Shawky","year":"2024","journal-title":"Trends Food Sci. Technol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Varma, S., and Simon, R. (2006). Bias in error estimation when using cross-validation for model selection. BMC Bioinform., 7.","DOI":"10.1186\/1471-2105-7-91"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Brodersen, K.H., Ong, C.S., Stephan, K.E., and Buhmann, J.M. (2010). The balanced accuracy and its posterior distribution. Proceedings of the 20th International Conference on Pattern Recognition 2010, Istanbul, Turkey, 23\u201326 August 2010, IEEE.","DOI":"10.1109\/ICPR.2010.764"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Chicco, D., and Jurman, G. (2020). The advantages of the Matthews correlation coefficient over F1 score and accuracy in binary classification evaluation. BMC Genom., 21.","DOI":"10.1186\/s12864-019-6413-7"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1482","DOI":"10.1080\/10942912.2012.723231","article-title":"Changes in Volatile Compounds of Black Cumin (Nigella sativa L.) Seed Oil During Thermal Oxidation","volume":"17","author":"Kiralan","year":"2014","journal-title":"Int. J. Food Prop."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/0377-0427(87)90125-7","article-title":"Silhouettes: A graphical aid to the interpretation and validation of cluster analysis","volume":"20","author":"Rousseeuw","year":"1987","journal-title":"J. Comput. Appl. Math."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1007\/BF01908075","article-title":"Comparing partitions","volume":"2","author":"Hubert","year":"1985","journal-title":"J. Classif."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"124894","DOI":"10.1016\/j.talanta.2023.124894","article-title":"Authentication and identification of Lamiaceae family with cyclic voltammetry fingerprint-PCA-LDA and determination of the used phenolic contents for classification using chromatographic analyses","volume":"265","author":"Tarighat","year":"2023","journal-title":"Talanta"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"103302","DOI":"10.1016\/j.rechem.2026.103302","article-title":"Performance of classification tools for small Lamiaceae herb samples","volume":"26","author":"Karpinska","year":"2026","journal-title":"Results Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"103403","DOI":"10.1016\/j.jfca.2019.103403","article-title":"Portable near-infrared spectroscopy for rapid authentication of adulterated paprika powder","volume":"87","author":"Oliveira","year":"2020","journal-title":"J. Food Compos. Anal."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"105044","DOI":"10.1016\/j.jfca.2022.105044","article-title":"Detection of cumin powder adulteration with allergenic nutshells using FT-IR and portable NIRS coupled with chemometrics","volume":"116","author":"Tumbajulca","year":"2023","journal-title":"J. Food Compos. Anal."}],"container-title":["Foods"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-8158\/15\/18\/3245\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T14:25:16Z","timestamp":1789395916000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-8158\/15\/18\/3245"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,14]]},"references-count":20,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["foods15183245"],"URL":"https:\/\/doi.org\/10.3390\/foods15183245","relation":{},"ISSN":["2304-8158"],"issn-type":[{"value":"2304-8158","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,14]]}}}