Food Ellagitannins–Occurrence, Effects of Processing and Storage

Abstract

Interest in ellagitannins and ellagic acid has increased over the past few years due to its properties as a micronutrient. Ellagitannins are complex plant polyphenols composed of hexahydroxydiphenoyl moieties esterified to a sugar. Fruits (especially berries and nuts) are rich sources of ellagitannins and ellagic acid, a hydrolytic product of ellagitannins. These secondary metabolites give the characteristic taste to the fruits and their products, and also play an important role in food processing. This paper reviews research about occurrence in foods, change during process, and antioxidant activity of ellagitannins and ellagic acid.

Keywords:

• foods
• ellagitannins
• ellagic acid
• antioxidant activity

ACKNOWLEDGEMENT

The authors thank Associate Professor Kezban CANDOĞAN (Department of Food Engineering, Ankara University) and Dr. Müslüm Yilmaz for the critical reading of the manuscript.

Notes

^a Contents are expressed as means ± SD in mg/kg FW

^b ETs were quantified as gallic acid equivalents in soluble form in the extracts and as EA equivalents after 20 h of acid hydrolysis in the methanol extract and extraction residue (results shown in parentheses)

* mg/100 g FW

** mg/100 g DW

*** mg/L

**** wild cultivar

*According to DPPH method