Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive Oil
The impact of the olive oil refining process on major antioxidant compound levels was evaluated by means of UHPLC analysis of lampante olive oils collected at different stages of the refining procedure (degumming, chemical and physical flash neutralization, bleaching, and deodorization). For this pu...
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| Format: | Article |
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MDPI AG
2020-03-01
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| Series: | Foods |
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| Online Access: | https://www.mdpi.com/2304-8158/9/3/292 |
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| author | Paolo Lucci Valentina Bertoz Deborah Pacetti Sabrina Moret Lanfranco Conte |
| author_facet | Paolo Lucci Valentina Bertoz Deborah Pacetti Sabrina Moret Lanfranco Conte |
| author_sort | Paolo Lucci |
| collection | DOAJ |
| description | The impact of the olive oil refining process on major antioxidant compound levels was evaluated by means of UHPLC analysis of lampante olive oils collected at different stages of the refining procedure (degumming, chemical and physical flash neutralization, bleaching, and deodorization). For this purpose, the evolution of the tocopherol fraction was investigated by means of the UHPLC-FL method, while the influence of the refining process on the total hydrolyzed phenolic content was assessed by measuring hydroxytyrosol and tyrosol levels after acid hydrolysis of the phenolic extracts. Refining was found to have a marked effect on total hydroxytyrosol and tyrosol contents, as they are completely removed in the early steps of the refining procedure. In contrast, the variation trends of tocopherols are not always clear-cut, and significant decreases in content from 7% to 16% were only revealed during refining in four out of nine samples. In addition, five of the nine refined oils showed final tocopherol concentrations higher than 200 mg/kg, the limit imposed by international standards regarding the content of such compounds in commercial olive oils. This study supports the need for a revision of the International Olive Oil Council (IOC) standard relative to the limit established for tocopherol addition to refined oils to avoid possible legal and economic trade issues. |
| first_indexed | 2024-12-13T12:15:54Z |
| format | Article |
| id | doaj.art-6f24381ee9254d2a9cf93cb15fd311f8 |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-12-13T12:15:54Z |
| publishDate | 2020-03-01 |
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| spelling | doaj.art-6f24381ee9254d2a9cf93cb15fd311f82022-12-21T23:46:44ZengMDPI AGFoods2304-81582020-03-019329210.3390/foods9030292foods9030292Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive OilPaolo Lucci0Valentina Bertoz1Deborah Pacetti2Sabrina Moret3Lanfranco Conte4Department of Agri-Food, Animal and Environmental Sciences, University of Udine, via Sondrio 2/a, 33100 Udine, ItalyDepartment of Agri-Food, Animal and Environmental Sciences, University of Udine, via Sondrio 2/a, 33100 Udine, ItalyDepartment of Agricultural, Food, and Environmental Sciences, Marche Polytechnic University, Via Brecce Bianche, 60131 Ancona, ItalyDepartment of Agri-Food, Animal and Environmental Sciences, University of Udine, via Sondrio 2/a, 33100 Udine, ItalyDepartment of Agri-Food, Animal and Environmental Sciences, University of Udine, via Sondrio 2/a, 33100 Udine, ItalyThe impact of the olive oil refining process on major antioxidant compound levels was evaluated by means of UHPLC analysis of lampante olive oils collected at different stages of the refining procedure (degumming, chemical and physical flash neutralization, bleaching, and deodorization). For this purpose, the evolution of the tocopherol fraction was investigated by means of the UHPLC-FL method, while the influence of the refining process on the total hydrolyzed phenolic content was assessed by measuring hydroxytyrosol and tyrosol levels after acid hydrolysis of the phenolic extracts. Refining was found to have a marked effect on total hydroxytyrosol and tyrosol contents, as they are completely removed in the early steps of the refining procedure. In contrast, the variation trends of tocopherols are not always clear-cut, and significant decreases in content from 7% to 16% were only revealed during refining in four out of nine samples. In addition, five of the nine refined oils showed final tocopherol concentrations higher than 200 mg/kg, the limit imposed by international standards regarding the content of such compounds in commercial olive oils. This study supports the need for a revision of the International Olive Oil Council (IOC) standard relative to the limit established for tocopherol addition to refined oils to avoid possible legal and economic trade issues.https://www.mdpi.com/2304-8158/9/3/292hydroxytyrosollampante oilolive oilphenolic compoundsrefiningtyrosoltocopherolsultra-high performance liquid chromatography |
| spellingShingle | Paolo Lucci Valentina Bertoz Deborah Pacetti Sabrina Moret Lanfranco Conte Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive Oil Foods hydroxytyrosol lampante oil olive oil phenolic compounds refining tyrosol tocopherols ultra-high performance liquid chromatography |
| title | Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive Oil |
| title_full | Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive Oil |
| title_fullStr | Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive Oil |
| title_full_unstemmed | Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive Oil |
| title_short | Effect of the Refining Process on Total Hydroxytyrosol, Tyrosol, and Tocopherol Contents of Olive Oil |
| title_sort | effect of the refining process on total hydroxytyrosol tyrosol and tocopherol contents of olive oil |
| topic | hydroxytyrosol lampante oil olive oil phenolic compounds refining tyrosol tocopherols ultra-high performance liquid chromatography |
| url | https://www.mdpi.com/2304-8158/9/3/292 |
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