engleski

Adsorption of individual polyphenol groups from apples onto β-glucan

The aim of this work was to obtain information about interactions between individual groups of polyphenols from apples and β-glucan. Polyphenols were extracted from peel and flesh of apple Idared with ultrasonic assisted extraction. Different groups of polyphenols from apple were separated by using the gel chromatographic method in a glass column with Sephadex LH-20 gel. Polyphenols were characterized by using reversed-phase high- performance liquid chromatography. In the apple flesh flavan-3-ols were present in the first fraction, then phenolic acids in the second and the flavonols in the third. In the apple peel flavan-3-ols were presented in the first fraction, then anthocyanins in the second and flavonols in the third. Interactions between polyphenols from apples and β-glucan were studied through adsorption process. The adsorption was conducted at 25 °C and pH 5.5 for 16 h. Adsorbed polyphenols were determined with reversed-phase high- performance liquid chromatography. In order to obtain information about adsorption process different models were applied. The experimental data (amount of adsorbed (qe) and un-adsorbed (ce) polyphenols) were modelled with non-linear regression using adsorption isotherm equations like Langmuir, Freundlich and Dubinin- Radushkevich. Apple polyphenols interacted with β- glucan. Polyphenols from peel showed slightly higher adsorption capacity than polyphenols from flesh. It was shown that adsorption was concentration depended process. It can be suggested that bonds between individual groups of polyphenols and β-glucan were H bonds and Van der Waals forces.

adsorption ; interactions ; polyphenols ; β-glucan

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