M. Elena Díaz-Rubio

Dietary fiber and antioxidant capacity in Fucus vesiculosus products

Several nutraceutical products have been developed from Fucus vesiculosus, a brown edible seaweed, rich in dietary fiber and polyphenolic antioxidants (phlorotannins). The aim of this work was to compare the antioxidant capacity and polysaccharide composition of raw Fucus with those of some common commercial nutraceuticals. All tested products contained a high percentage of dietary fiber (45–59%), raw Fucus powder being the sample with the highest content. Also, raw Fucus powder exhibited significantly higher antioxidant capacity (determined by FRAP, ABTS and ORAC assays) than the commercial fucoidans and commercial antioxidant extracts. Polyphenols (phlorotannins) seem to be the main contributors to Fucus’ antioxidant capacity in both raw powder and commercial fucoidans.

Non-Extractable Polyphenols in Plant Foods: Nature, Isolation, and Analysis

Abstract Polyphenol content in plant foods is usually considered as that found in their corresponding aqueous-organic extracts. Nevertheless, polyphenols found in these extracts would correspond only to a fraction of these phytochemicals, the extractable polyphenols (EPP). The extractions leave a residue, commonly neglected, containing an understudied fraction of plant foods polyphenols, the so-called non-extractable polyphenols (NEPP). NEPP comprise polyphenols belonging to different classes, such as macromolecular polyphenols or single polyphenols associated with cell wall macromolecules. Although only a minor part of the existing literature on polyphenols in plant foods have dealt with NEPP, the existing data show that they are even more abundant than EPP in many plant foods. The present chapter aims to provide an overview of NEPP in plant foods, including their nature, procedures for their isolation, current analytical methods, content in several foods and extracts, and potential applications.Polyphenol content in plant foods is usually considered as that found in their corresponding aqueous-organic extracts. Nevertheless, polyphenols found in these extracts would correspond only to a fraction of these phytochemicals, the extractable polyphenols (EPP). The extractions leave a residue, commonly neglected, containing an understudied fraction of plant foods polyphenols, the so-called non-extractable polyphenols (NEPP). NEPP comprise polyphenols belonging to different classes, such as macromolecular polyphenols or single polyphenols associated with cell wall macromolecules. Although only a minor part of the existing literature on polyphenols in plant foods have dealt with NEPP, the existing data show that they are even more abundant than EPP in many plant foods. The present chapter aims to provide an overview of NEPP in plant foods, including their nature, procedures for their isolation, current analytical methods, content in several foods and extracts, and potential applications.

Beverages have an appreciable contribution to the intake of soluble dietary fibre: a study in the Spanish diet

Beverages are generally not taken into account to determine the intakes of dietary fibre (DF) in diets. Soluble dietary fibre (SDF) content was determined in common alcoholic and non-alcoholic beverages – ranging from 0.18 g/l in white wine to 9.01 g/l in instant coffee – and their contribution to the DF intake in the Spanish Mediterranean diet was estimated as 2.13 g/person/day. It is concluded that beverages provide an appreciable amount of SDF in the diet, and the omission of its contribution may lead to underestimate DF intakes.