title: Innovative microwave-assisted hydrolysis of ellagitannins and quantification as ellagic acid equivalents.
abstract: The health-promoting effects of ellagic acid and its intestinal degradation products are well-known. In plants, ellagic acid mainly appears in the form of its precursors, the so-called ellagitannins. Therefore, determination of total ellagic acid content has been accomplished by cleaving ellagitannins with high temperatures and strong acids. Microwave-assisted extraction (MAE) has been shown to be a very effective and quick extraction technique. The aim of the present study was to establish an MAE-based method for a rapid hydrolysis of ellagitannins and to compare this method with a conventional acid hydrolysis. For this purpose, strawberries (Fragaria x ananassa), which have been identified as a major source of ellagitannins in human diet, were used as a model. The newly developed MAE method was quicker, less chemical-consuming and more effective in hydrolysing ellagitannins.
authors.affiliation: Institute of Life Technologies, University of Applied Sciences Western Switzerland, Route du Rawyl 47, CH-1950 Sion, Switzerland.
authors.forename: Grigorios
authors.initials: G
authors.lastname: Theocharis
authors.forename: Wilfried
authors.initials: W
authors.lastname: Andlauer
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000295:instrumentation / Q000379:methods*; D004610:Ellagic Acid / Q000737:chemistry*; D031985:Fragaria / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry; D006868:Hydrolysis; D047348:Hydrolyzable Tannins / Q000737:chemistry*; D008872:Microwaves
chemical_list: D047348:Hydrolyzable Tannins; D004610:Ellagic Acid