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.

Effects of ground flaxseed on bread quality, staling, and in particular on γ-tocopherol and unsaturated fatty acid composition were determined. Ground flaxseed was added in concentrations of 10, 15, 20, and 25% to wheat flour sample. Results showed that the use of ground flaxseed at a 10% level markedly increased loaf volume, specific loaf volume, Dallman degree and retarded bread staling. Oil and γ-tocopherol content and proportion of linolenic acid in fatty acid composition went up as the ratio of flaxseed flour in bread formulation was increased. Oil, γ-tocopherol content, and proportion of linolenic acid in fatty acid varied in the range of 1.48—8.20%, 0.2—0.24 g/kg sample oil, and 50.25—55.55%, respectively in breads enriched with flaxseed flour. During bread staling, the change in peroxide values, γ-tocopherol content, and fatty acid distribution were not significant. Bread samples were tested for crust color appearance, crumb color, shape-symmetry, external appearance, mouth feel, and taste-aroma. The general acceptability was good at the level of 15% flaxseed flour addition and other substitute levels were found satisfactory.

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