کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1410646 | 1501873 | 2008 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effect of ferrous and ferric ions on copigmentation in model solutions
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Effect of ferrous and ferric ions on copigmentation in model solutions Effect of ferrous and ferric ions on copigmentation in model solutions](/preview/png/1410646.png)
چکیده انگلیسی
The thermodynamics of the molecular association process between malvidin-3-O-glucoside and ellagic acid (so-called “copigmentation”) was studied in model wine solutions in the presence and absence, respectively, of ferrous and ferric ions. The Gibbs free energy, enthalpy, and entropy values of the complexation process were determined by means of a spectrofluorometric method. A combination of the Job's method with the van't Hoff theory was used for data evaluation. The results show the generally exothermic character of the process. The free enthalpy changes obtained during formation of malvidin-3-O-glucoside-ellagic acid complexes increase from â17.8Â kJ/mol to â40.5Â kJ/mol in the presence of Fe(II) ions. The increased free enthalpy is a consequence of the drastic reduction of entropy change due to the slight “swinging” movement of the interacting malvidin and ellagic acid molecules in the complexes stabilized by the ferrous ions. These results are also supported by the findings of other authors stating that iron ions play an important role in the stabilization of color in the plant kingdom and various plant products.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 891, Issues 1â3, 26 November 2008, Pages 471-474
Journal: Journal of Molecular Structure - Volume 891, Issues 1â3, 26 November 2008, Pages 471-474
نویسندگان
Sándor Kunsági-Máté, Erika Ortmann, László Kollár, Kornélia Szabó, Martin Pour Nikfardjam,