Innovative microwave-assisted hydrolysis of ellagitannins and quantification as ellagic acid equivalents.

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.

Theocharis G ，Andlauer W 《-》

Evolution of ellagitannin content and profile during fruit ripening in Fragaria spp.

Gasperotti M ，Masuero D ，Guella G ，Palmieri L ，Martinatti P ，Pojer E ，Mattivi F ，Vrhovsek U ... -  《-》

Evaluation of antiproliferative, anti-type 2 diabetes, and antihypertension potentials of ellagitannins from strawberries (Fragaria × ananassa Duch.) using in vitro models.

Pinto Mda S ，de Carvalho JE ，Lajolo FM ，Genovese MI ，Shetty K ... -  《-》

Phenolic composition and antioxidant activities in flesh and achenes of strawberries (Fragaria ananassa).

High performance liquid chromatography coupled with diode array and coulometric array detectors were used to characterize and quantify phenolic compounds in achenes and flesh of ripe strawberries (cv Totem and Puget Reliance). Total phenolics and total monomeric anthocyanins were measured and antioxidant activities were evaluated by the FRAP and the ORAC assays. Strawberries contained 1% achenes on a fresh weight basis; however, they contributed to about 11% of total phenolics and 14% of antioxidant activities in strawberries. Ellagic acid, ellagic acid glycosides, and ellagitannins were the main contributors to the antioxidant activities of achenes. The major anthocyanin in flesh was pelargonidin-3-glucoside, whereas achenes consisted of nearly equal amounts of cyanidin-3-glucoside and pelargonidin-3-glucoside. Phenolic content and antioxidant activity of strawberry achenes were reduced by industrial processing. However, the levels were still high and strawberry waste byproduct could thus be a possible source of nutraceuticals or natural antioxidants.

Aaby K ，Skrede G ，Wrolstad RE 《JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY》

Acid hydrolysis of crude tannins from infructescence of Platycarya strobilacea Sieb. et Zucc to produce ellagic acid.

Zhang L ，Wang Y ，Xu M 《-》