title: Determination of organic milk authenticity using carbon and nitrogen natural isotopes.
abstract: Natural stable isotopes of carbon and nitrogen ((12)C, (13)C, (14)N, (15)N) have abundances unique to each living creature. Therefore, measurement of the stable isotope ratio of carbon and nitrogen (δ(13)C=(13)C/(12)C, δ(15)N=(15)N/(14)N) in milk provides a reliable method to determine organic milk (OM) authenticity. In the present study, the mean δ(13)C value of OM was higher than that of conventional milk (CM), whereas the mean δ(15)N value of OM was lower than that of CM; nonetheless both δ(13)C and δ(15)N values were statistically different for the OM and CM (P<0.05). Furthermore, the values of δ(13)C and δ(15)N were found to differ statistically with the collection date and the milk brand (P<0.05). The combination of δ(13)C and δ(15)N values was more effective than either value alone in distinguishing between OM and CM. The results of the present study, which is based on preliminary data from a limited sample size and sampling period, could be highly valuable and helpful for consumers, the food industry, and/or government regulatory agencies as it can prevent fraudulent labelling of organic food. Further studies include additional analyses of other milk brands and analyses over longer time periods in order to accurately determine OM authenticity using stable isotopes of carbon and nitrogen.
authors.affiliation: Department of Applied Bioscience, College of Life and Environmental Science, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Ill-Min
authors.initials: IM
authors.lastname: Chung
authors.affiliation: Department of Microbiology, College of Natural Sciences, Pusan National University, Pusandaehak-ro 63 beon-gil, Geumjeong-gu, Busan 609-735, Republic of Korea.
authors.forename: Inmyoung
authors.initials: I
authors.lastname: Park
authors.affiliation: Department of Applied Bioscience, College of Life and Environmental Science, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Jae-Yeon
authors.initials: JY
authors.lastname: Yoon
authors.affiliation: Department of Applied Bioscience, College of Life and Environmental Science, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Ye-Seul
authors.initials: YS
authors.lastname: Yang
authors.affiliation: Department of Applied Bioscience, College of Life and Environmental Science, Konkuk University, Seoul 143-701, Republic of Korea. Electronic address: kshkim@konkuk.ac.kr.
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis*; D002417:Cattle; D013058:Mass Spectrometry; D008892:Milk / Q000737:chemistry*; D009587:Nitrogen Isotopes / Q000032:analysis*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes
keywords: Authenticity; Carbon isotope; Nitrogen isotope; Organic milk; Stable isotope ratio mass spectrometry