Volume 214, 1 January 2017, Pages 61–66
- a Laboratory of Chemistry – Biochemistry – Physical Chemistry of Foods, Department of Nutrition & Dietetics, Harokopion University, 70 El. Venizelou Str., Kallithea, 17671 Athens, Greece
- b Department of Food Science and Technology, Faculty of Agriculture, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- c Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Patriarchou Gregoriou and Neapoleos Str., Aghia Paraskevi, 15310 Athens, Greece
Highlights
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- Holistic approach for the extraction of whole pomegranate polyphenols was proposed.
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- The solvent system of the extraction was aqueous solutions of cyclodextrins.
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- Complex formation of polyphenols was investigated with Nuclear Magnetic Resonance Spectroscopy.
Abstract
Pomegranate
is a source of bioactive phytochemicals. The objective of this study
was the derivation of a sustainable method to exploit the whole fruit,
both edible and non-edible parts, as a source of polyphenols.
Pomegranate peel contains a 10-fold higher phenolic content than the
pulp. The fruit was freeze-dried and the resulting dry matter was
extracted with solid-liquid percolation equipment using non-toxic and
eco-friendly extraction solvents: either deionized water or aqueous
solutions of cyclodextrins. Cyclodextrins (CDs) are known molecular
encapsulators and our results prove enhancement of the extraction of
pomegranate polyphenols by 20%. In order to examine the formation of
inclusion complexes between CD’s and polyphenols of the extract,
polyphenols were isolated using solid-phase extraction. NMR studies with
the purified extracts and the individual CDs confirmed inclusion
complex formation in water. Pomegranate liquid extracts may be used as
raw materials for several end-users in the food, cosmetic and
pharmaceutical industries.
Chemical compounds studied in this article
- Beta-cyclodextrin (PubChem CID: 6518168);
- Hydroxypropyl-beta-cyclodextrin (PubChem CID: 44134771);
- DPPH, free radical (PubChem CID: 2735032);
- Trolox (PubChem CID: 40634)
Keywords
- Cyclodextrins;
- Polyphenols;
- Inclusion complex formation;
- NMR spectroscopy;
- Extraction
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