{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T20:49:48Z","timestamp":1777495788012,"version":"3.51.4"},"reference-count":18,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2002,6,1]],"date-time":"2002-06-01T00:00:00Z","timestamp":1022889600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Americ Oil Chem Soc"],"published-print":{"date-parts":[[2002,6]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The effects of four phenolic compounds occurring in olives and virgin olive oil, namely, oleuropein, hydroxytyrosol, 3,4\u2010dihydroxyphenylethanol\u2010elenolic acid (3,4\u2010DHPEA\u2010EA) and 3,4\u2010dihydroxyphenylethanol\u2010elenolic acid dialdehyde (3,4\u2010DHPEA\u2010EDA), on the oxidative stability of stripped olive oil\u2010in\u2010water emulsions were studied at three pH values in the presence or absence of ferric chloride at 60\u00b0C. In the stability test, the addition of phenolic compounds in emulsions at pH 5.5 significantly extended the induction time of lipid oxidation, and the activities in decreasing order were 3,4\u2010DHPEA\u2010EA&gt; 3,4\u2010DHPEA\u2010EDA&gt;hydroxytyrosol&gt;\u03b1\u2010tocopherol\u223coleuropein \u226bcontrol. The effect of concentration, iron, and pH on the antioxidant activity of the phenolic compounds in stripped olive oil\u2010in\u2010water emulsions was analyzed by response surface methodology. Oleuropein and hydroxytyrosol enhanced the prooxidant effect of ferric chloride at pH 3.5 and pH 5.5 but not at pH 7.4. The 3,4\u2010DHPEA\u2010EDA reduced the prooxidant effect of ferric chloride at pH 5.5 and pH 7.4, but at pH 3.5 prooxidant effects were evident at higher phenol concentration. The 3,4\u2010DHPEA\u2010EA reduced the prooxidant effect of ferric ions at all pH values tested. Differences in activity of the phenols may be explained by consideration of their free radical scavenging activity and ferric reducing capacity.<\/jats:p>","DOI":"10.1007\/s11746-002-0524-4","type":"journal-article","created":{"date-parts":[[2006,11,22]],"date-time":"2006-11-22T05:50:35Z","timestamp":1164174635000},"page":"571-576","source":"Crossref","is-referenced-by-count":60,"title":["Effects of pH and ferric ions on the antioxidant activity of olive polyphenols in oil\u2010in\u2010water emulsions"],"prefix":"10.1002","volume":"79","author":[{"given":"F\u00e1tima","family":"Paiva\u2010Martins","sequence":"first","affiliation":[{"name":"Centro de Investiga\u00e7\u00e3o em Qu\u00edmica, Departamento de Qu\u00edmica, Faculdade de Ci\u00eancias Universidade do Porto 4169\u2010007 Porto Portugal"}]},{"given":"Michael H.","family":"Gordon","sequence":"additional","affiliation":[{"name":"School of Food Biosciences The University of Reading Whiteknights P.O. Box 226 RG6 6AP Reading United Kingdom"}]}],"member":"311","published-online":{"date-parts":[[2002,6]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1021\/jf00035a076"},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF02523530"},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1021\/jf990009o"},{"key":"e_1_2_1_5_1","first-page":"2480","article-title":"F. Paiva\u2010Martins, and M. Almeida, Antioxidant Activity of Hydroxytyrosol Acetate Compared with Other Olive Oil Polyphenols","volume":"49","author":"Gordon M.H.","year":"2001","journal-title":"Ibid."},{"key":"e_1_2_1_6_1","first-page":"2267","article-title":"Lipid Oxidation in Emulsions as Affected by Charge Status of Antioxidants and Emulsion Droplets","volume":"47","author":"Mei L.","year":"1999","journal-title":"Ibid."},{"key":"e_1_2_1_7_1","first-page":"4112","article-title":"The Effects of Surfactant Type, pH, and Chelators on the Oxidation of Salmon Oil\u2010in\u2010Water Emulsions","volume":"47","author":"Mancuso J.R.","year":"1999","journal-title":"Ibid."},{"key":"e_1_2_1_8_1","first-page":"2496","article-title":"Effect of pH on Antioxidant Activity of \u00e1\u2010Tocopherol and Trolox in Oilin\u2010Water Emulsions","volume":"44","author":"Huang S.","year":"1996","journal-title":"Ibid."},{"key":"e_1_2_1_9_1","first-page":"437","article-title":"Effectiveness of Lipid\u2010 and Water\u2010Soluble Phenolic Antioxidants in the Autoxidation of Polyunsaturated Fatty Acids Esters in Microheterogeneous Solutions","volume":"4","author":"Roginsky V.A.","year":"1990","journal-title":"Biol. Membr."},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0891-5849(96)00426-1"},{"key":"e_1_2_1_11_1","first-page":"405","article-title":"Free Radicals in Ion Containing Systems","volume":"3","author":"Dunford H.B.","year":"1987","journal-title":"Ibid."},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/jlac.198319830417"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/0031-9422(86)80018-8"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1021\/jf9507349"},{"key":"e_1_2_1_15_1","first-page":"4214","article-title":"Isolation and Characterization of the Antioxidant Component 3,4\u2010Dihydroxyphenylethyl 4\u2010Formyl\u20103\u2010formylmethyl\u20104\u2010hexenoate from Olive (Olea europaea)","volume":"49","author":"Paiva\u2010Martins F.","year":"2001","journal-title":"Ibid."},{"key":"e_1_2_1_16_1","unstructured":"International Union of Pure and Applied Chemistry Method 2.432."},{"key":"e_1_2_1_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0023-6438(95)80008-5"},{"key":"e_1_2_1_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0076-6879(99)99005-5"},{"key":"e_1_2_1_19_1","volume-title":"Official Methods and Recommended Practices of the American Oil Chemists' Society","year":"1998"}],"container-title":["Journal of the American Oil Chemists' Society"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1007%2Fs11746-002-0524-4","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aocs.onlinelibrary.wiley.com\/doi\/pdf\/10.1007\/s11746-002-0524-4","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T15:29:30Z","timestamp":1759937370000},"score":1,"resource":{"primary":{"URL":"https:\/\/aocs.onlinelibrary.wiley.com\/doi\/10.1007\/s11746-002-0524-4"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2002,6]]},"references-count":18,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2002,6]]}},"alternative-id":["10.1007\/s11746-002-0524-4"],"URL":"https:\/\/doi.org\/10.1007\/s11746-002-0524-4","archive":["Portico"],"relation":{},"ISSN":["0003-021X","1558-9331"],"issn-type":[{"value":"0003-021X","type":"print"},{"value":"1558-9331","type":"electronic"}],"subject":[],"published":{"date-parts":[[2002,6]]}}}