Pectin as a bioactive polysaccharide - Extracting tailored function from less

Abstract

Pectin is a complex structural polysaccharide located in the cell wall and middle lamella of higher plants. The homogalacturon (HG) regions may be methyl esterified or de-esterified to create a block co-polymer structure. The HG backbone may be interrupted by neutral sugar side chains forming the rhamnogalacturon I (RGI) region, or rhamnogalacturon II (RGII), a conserved structure. In addition, protein, ferulic acid and acetyl groups may be found on some sources of pectin. While pectin has positive health effects against many diseases related to inflammation and as a delivery vehicle for bioactives for colon targeted delivery, conflicting results are reported and may be related to paucity of physico-chemical information or source of pectin. Pectin structure can be enzymatically or chemically modified to produce molecular fragments that can be used to successfully entrap phytochemicals for emulsion based targeted delivery to the colon. Likewise, charge modified pectin allows the development of delivery systems based on hydrogel technology. Pectin is recognized as a soluble dietary fiber, and likely has multiple outcomes against cardiovascular disease. More recent evidence also points to the role of neutral sugars, arabino-oligosaccharides, and ferulic acid and other phenolics associated with pectin as a dietary fiber and in vitro fermentability of selected domains of pectin and associated colonic metabolites on inflammation and gut health. While the mechanism of the positive effects of pectin remain to be elucidated, emerging evidence points to synergism between specific domains of pectin structure and other food constituents. (C) 2014 Elsevier Ltd. All rights reserved.