Differentiation of Fresh Greek Orange Juice of the Merlin Cultivar According to Geographical Origin Based on the Combination of Organic Acid and Sugar Content as well as Physicochemical Parameters Using Chemometrics
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The aim of the present study was to differentiate fresh Greek orange juice prepared from the Merlin cultivar according to geographical origin, based on organic acid/sugar content, and physicochemical parameter analysis, using chemometrics. For this purpose, oranges were collected during the harvesting period 2013–2014 from four different regions in Greece where Merlin oranges are produced. The analysis of organic acids and sugars was performed using a modified high pressure liquid chromatographic (HPLC–DAD/RI) method. Applying MANOVA and LDA analysis to the collected data, orange juices were successfully classified according to geographical origin (correct classification rate 83.3%). For validation purposes of the applied model, oranges from the harvesting period 2014–2015 were also collected and new instrumental and chemometric analysis carried out involving orange juice from both harvesting periods. Cumulative results showed that the classification rate remained practically constant, recording a correct classification rate of 80.4%, confirming the discriminatory power of the applied model. In order to further improve the overall classification rate, physicochemical parameter data were subjected to chemometric analysis along with organic acid and sugar content data. Results showed that the combination of organic acids, sugars, and physicochemical parameters somewhat increased the overall correct prediction rate to 82.0%. Present results enhance the potential of multi-parameter analysis for the correct geographical differentiation of Greek fresh orange juice, aiding to product quality and authenticity control.
KeywordsDifferentiation Orange juice Geographical origin Organic acids Sugars Physicochemical parameters Chemometrics
The authors are grateful to the Prefectural Government of Epirus, Greece, for the financial support provided through the research program: “New Knowledge-Determination of authenticity of selected foodstuffs from Epirus” funded by European and Greek funds. Special thanks to local orange producers of Messinia, Hania, Rhodes, and the cooperative of orange producers of Arta, for the donation of a portion of orange samples.
Compliance with Ethical Standards
This research was funded by European and Greek funds.
Conflict of Interest
Christos Nikolaou declares that he has no conflict of interest. Ioannis K. Karabagias declares that he has no conflict of interest. Ilias Gatzias declares that he has no conflict of interest. Stavros Kontakos declares that he has no conflict of interest. Anastasia Badeka declares that she has no conflict of interest. Michael G. Kontominas declares that he has no conflict of interest.
This article does not contain any studies with human or animal subjects.
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