{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:04:14Z","timestamp":1792789454186,"version":"4.5.0"},"reference-count":27,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Institute of Metrology, Thailand","award":["6907101\u0e14"],"award-info":[{"award-number":["6907101\u0e14"]}],"id":[{"id":"https:\/\/ror.org\/01357ty92","id-type":"ROR","asserted-by":"crossref"}]},{"award":["6907101\u0e14"],"award-info":[{"award-number":["6907101\u0e14"]}],"id":[{"id":"https:\/\/ror.org\/01357ty92","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Foods"],"abstract":"<jats:p>Meat adulteration, particularly the substitution of duck with chicken, threatens food authenticity, consumer trust, and regulatory compliance. However, converting DNA copy number measurements into meat mass fractions remains challenging. This study developed a digital PCR (dPCR)-based quantitative for determining chicken in duck. Singleplex and duplex dPCR assays targeting single-copy nuclear genes specific to chicken, duck and the conserved myostatin gene were developed and optimized. Five sets of binary chicken-in-duck mixtures were prepared and analyzed across 0\u2013100% (w\/w) to account for biological variability among meat sources. Five conversion approaches were evaluated: two conversion factor approaches based on the chicken-to-duck (kcd) and chicken-to-myo (kmyo) copy number ratios, two corresponding approaches without conversion factors (Nokcd and Myo), and a linear regression model (Std). Quantitative performance of all five conversion approaches was concentration-dependent, and no single approach was optimal across the entire range. Conversion factor approaches generally improved agreement with gravimetrically assigned values at low to intermediate levels but overestimated higher chicken fractions. The Std approach performed well at \u22655% (w\/w) but was less reliable at lower levels. Approaches selected based on their quantitative performance were further evaluated across different sample compositions and processing conditions and applied to commercial duck products. Overall, dPCR combined with an appropriate conversion approach may support quantitative determination of chicken in duck meat for food authenticity testing.<\/jats:p>","DOI":"10.3390\/foods15193523","type":"journal-article","created":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T18:43:24Z","timestamp":1790880204000},"page":"3523","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Conversion of DNA Copy Number Ratios to Mass Fractions for Quantifying Chicken Adulteration in Duck Meat by Digital PCR"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2605-9786","authenticated-orcid":false,"given":"Sasithon","family":"Temisak","sequence":"first","affiliation":[{"name":"Bioanalysis Group, Chemical Metrology and Biometry Department, National Institute of Metrology (NIMT), Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"given":"Jarupa","family":"Tunhyongnoppakoon","sequence":"additional","affiliation":[{"name":"Bioanalysis Group, Chemical Metrology and Biometry Department, National Institute of Metrology (NIMT), Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Jiranun","family":"Boonnil","sequence":"additional","affiliation":[{"name":"Bioanalysis Group, Chemical Metrology and Biometry Department, National Institute of Metrology (NIMT), Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"}]},{"given":"Ganyarat","family":"Thaiwan","sequence":"additional","affiliation":[{"name":"Department of Biology, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Chakkit","family":"Tanai","sequence":"additional","affiliation":[{"name":"Department of Biology, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Watiporn","family":"Yenchum","sequence":"additional","affiliation":[{"name":"Bioanalysis Group, Chemical Metrology and Biometry Department, National Institute of Metrology (NIMT), Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"}]},{"given":"Kanjana","family":"Hongthong","sequence":"additional","affiliation":[{"name":"Bioanalysis Group, Chemical Metrology and Biometry Department, National Institute of Metrology (NIMT), Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"}]},{"given":"Nusara","family":"Yinyom","sequence":"additional","affiliation":[{"name":"Bioanalysis Group, Chemical Metrology and Biometry Department, National Institute of Metrology (NIMT), Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Phattaraporn","family":"Morris","sequence":"additional","affiliation":[{"name":"Bioanalysis Group, Chemical Metrology and Biometry Department, National Institute of Metrology (NIMT), Pathumthani 12120, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2198-979X","authenticated-orcid":false,"given":"Pattanapong","family":"Thangsunan","sequence":"additional","affiliation":[{"name":"Division of Biochemistry and Biochemical Innovation, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,10,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.foodcont.2015.10.030","article-title":"Mislabelling of beef and poultry products sold in Malaysia","volume":"62","author":"Chuah","year":"2016","journal-title":"Food Control"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"012070","DOI":"10.1088\/1755-1315\/372\/1\/012070","article-title":"Duck Production for Food Security","volume":"372","author":"Ismoyowati","year":"2019","journal-title":"IOP Conf. Ser. Earth Environ. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Hu, J., Wei, H., Jiang, Y., Xue, Q., and Wang, F. (2025). DNA Barcoding in Meat Authentication: Principles, Applications, and Future Perspectives. Foods, 14.","DOI":"10.3390\/foods14203522"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6345","DOI":"10.1111\/ijfs.15375","article-title":"Accurate determination of meat mass fractions using DNA measurements for quantifying meat adulteration by digital PCR","volume":"56","author":"Temisak","year":"2021","journal-title":"Int. J. Food Sci. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1341","DOI":"10.1007\/s12161-021-02210-1","article-title":"Sensitive Detection of Chicken Meat in Commercial Processed Food Products Based on One-Step Colourimetric Loop-Mediated Isothermal Amplification","volume":"15","author":"Thangsunan","year":"2022","journal-title":"Food Anal. Methods"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"100017","DOI":"10.1016\/j.fochms.2021.100017","article-title":"Detection of species adulteration in meat products and Mozzarella-type cheeses using duplex PCR of mitochondrial cyt b gene: A food safety concern in Bangladesh","volume":"2","author":"Hossain","year":"2021","journal-title":"Food Chem. Mol. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1007\/s00003-023-01437-w","article-title":"Detection of adulterated meat products by a next-generation sequencing-based metabarcoding analysis within the framework of the operation OPSON X: A cooperative project of the German National Reference Centre for Authentic Food (NRZ-Authent) and the competent German food control authorities","volume":"18","author":"Kappel","year":"2023","journal-title":"J. Consum. Prot. Food Saf."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.foodres.2014.03.030","article-title":"Authenticity of meat products: Tools against fraud","volume":"60","author":"Sentandreu","year":"2014","journal-title":"Food Res. Int."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Wang, Q., Cai, Y., He, Y., Yang, L., and Pan, L. (2018). Collaborative ring trial of two real-time PCR assays for the detection of porcine- and chicken-derived material in meat products. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0206609"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.bdq.2016.05.002","article-title":"Fundamentals of multiplexing with digital PCR","volume":"10","author":"Whale","year":"2016","journal-title":"Biomol. Detect. Quantif."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Ren, J., Deng, T., Huang, W., Chen, Y., and Ge, Y. (2017). A digital PCR method for identifying and quantifying adulteration of meat species in raw and processed food. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0173567"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Griffiths, K.R., McLaughlin, J.L.H., Hall, F., Partis, L., Hansen, S.C., Tulloch, R., and Burke, D.G. (2023). Development of Seven New dPCR Animal Species Assays and a Reference Material to Support Quantitative Ratio Measurements of Food and Feed Products. Foods, 12.","DOI":"10.3390\/foods12203839"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1253","DOI":"10.1016\/j.foodchem.2016.11.032","article-title":"Comparison of DNA extraction methods for meat analysis","volume":"221","author":"Yumbul","year":"2017","journal-title":"Food Chem."},{"key":"ref_14","unstructured":"(2020). Molecular Biomarker Analysis-Detection of Animal-Derived Materials in Foodstuffs and Feedstuffs by Real-time PCR-Part 4: Chicken DNA Detection Method (Standard No. ISO\/TS-20224-4). 1st edition."},{"key":"ref_15","unstructured":"(2019). Biotechnology\u2014Requirements for Evaluating the Performance of Quantification Methods for Nucleic Acid Target Sequences\u2014qPCR and dPCR (Standard No. ISO 20395:2019)."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.bdq.2016.08.002","article-title":"Validation of a digital PCR method for quantification of DNA copy number concentrations by using a certified reference material","volume":"9","author":"Deprez","year":"2016","journal-title":"Biomol. Detect. Quantif."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Cai, Y., He, Y., Lv, R., Chen, H., Wang, Q., and Pan, L. (2017). Detection and quantification of beef and pork materials in meat products by duplex droplet digital PCR. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0181949"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"128622","DOI":"10.1016\/j.foodchem.2020.128622","article-title":"Quantitative determination of mutton adulteration with single-copy nuclear genes by real-time PCR","volume":"344","author":"Li","year":"2021","journal-title":"Food Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1046\/j.1365-2621.2003.00651.x","article-title":"Methods for the detection of beef and pork in foods using real-time polymerase chain reaction","volume":"38","author":"Laube","year":"2003","journal-title":"Int. J. Food Sci. Technol."},{"key":"ref_20","unstructured":"Kim, G., Jeong, J., Moon, S., Hwang, Y., Park, G., and Joo, S. (2008, January 10\u201315). Effects of muscle fibre type on meat characteristics of chicken and duck breast muscle. Proceedings of the 54th International Congress of Meat Science and Technology (54th ICoMST), Cape Town, South Africa."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"202","DOI":"10.3382\/ps.0720202","article-title":"Pekin Duckling and Broiler Chicken Pectoralis Muscle Structure and Composition","volume":"72","author":"Smith","year":"1993","journal-title":"Poult. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Hu, J., Song, L., Ning, M., Niu, X., Han, M., Gao, C., Feng, X., Cai, H., Li, T., and Li, F. (2024). A new chromosome-scale duck genome shows a major histocompatibility complex with several expanded multigene families. BMC Biol., 22.","DOI":"10.1186\/s12915-024-01817-0"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"5932","DOI":"10.1038\/s41467-021-26272-1","article-title":"Three chromosome-level duck genome assemblies provide insights into genomic variation during domestication","volume":"12","author":"Zhu","year":"2021","journal-title":"Nat. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1186\/gb-2005-6-2-207","article-title":"Insights into vertebrate evolution from the chicken genome sequence","volume":"6","author":"Furlong","year":"2005","journal-title":"Genome Biol."},{"key":"ref_25","unstructured":"(2024). Molecular Biomarker Analysis-Detection of Animal-Derived Materials in Foodstuffs and Feedstuffs by Real-Time PCR-Part 10:Duck DNA Detection Method (Standard No. ISO\/TS-20224-10)."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2130","DOI":"10.1016\/j.foodchem.2013.05.032","article-title":"Assessment of DNA degradation induced by thermal and UV radiation processing: Implications for quantification of genetically modified organisms","volume":"141","author":"Ballari","year":"2013","journal-title":"Food Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1003","DOI":"10.1021\/ac202578x","article-title":"Evaluation of a Droplet Digital Polymerase Chain Reaction Format for DNA Copy Number Quantification","volume":"84","author":"Pinheiro","year":"2012","journal-title":"Anal. Chem."}],"container-title":["Foods"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-8158\/15\/19\/3523\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T11:54:02Z","timestamp":1791460442000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-8158\/15\/19\/3523"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,1]]},"references-count":27,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["foods15193523"],"URL":"https:\/\/doi.org\/10.3390\/foods15193523","relation":{},"ISSN":["2304-8158"],"issn-type":[{"value":"2304-8158","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,1]]}}}