Influence of Pectin Structural Properties on Interactions with Divalent Cations and Its Associated Functionalities

Abstract

Pectin is an anionic cell wall polysaccharide which is known to interact with divalent cations via its nonmethylesterified galacturonic acid units. Due to its cation‐binding capacity, extracted pectin is frequently used for several purposes, such as a gelling agent in food products or as a biosorbent to remove toxic metals from waste water. Pectin can, however, possess a large variability in molecular structure, which influences its cation‐binding capacity. Besides the pectin structure, several extrinsic factors, such as cation type or pH, have been shown to define the cation binding of pectin. This review paper focuses on the research progress in the field of pectin‐divalent cation interactions and associated functional properties. In addition, it addresses the main research gaps and challenges in order to clearly understand the influence of pectin structural properties on its divalent cation‐binding capacity and associated functionalities. This review reveals that many factors, including pectin molecular structure and extrinsic factors, influence pectin–cation interactions and its associated functionalities, which makes it difficult to predict the pectin–cation‐binding capacity. Despite the limited information available, determination of the cation‐binding capacity of pectins with distinct structural properties using equilibrium adsorption experiments or isothermal titration calorimetry is a promising tool to gain fundamental insights into pectin–cation interactions. These insights can then be used in targeted pectin structural modification, in order to optimize the cation‐binding capacity and to promote pectin–cation interactions, for instance for a structure build‐up in food products without compromising the mineral nutrition value.

Dietary Fibers from Fruits and Vegetables and Their Health Benefits via Modulation of Gut Microbiota

“…The degree of methyl esterification (DE) is calculated as the percentage of methylesterified carboxyl groups in the pectin chain and affects its gelling properties (H. Zhang et al., ). Of the many structural properties of pectin, DE has received much attention as it is considered to be the main factor affecting the cation‐binding capacity of DFs (Celus, Kyomugasho, Van Loey, Grauwet, & Hendrickx, ). The DE of pectin varies with the processing conditions (pH, temperature, Ca 2+ concentration, and gelation time), source, and ripeness (Zhao et al., ).…”

Characterization of Seed, Oil, and Fatty Acid Methyl Esters of an Ethyl Methanesulfonate Mutant of Camelina sativa with Reduced Seed‐Coat Mucilage

“…In Arabidopsis SCM, which is composed of RGI and HG pectins, forms ionic cross‐links with Ca 2+ salt bridges (Macquet et al, ). Pectins, such as HG and RGI, chelate divalent cations (e.g., Ca 2+ , Cu 2+ , Fe 2+ , Mg 2+ , and Zn 2+ ) (Celus et al, ). Pectins also chelate monovalent cations (e.g., K + ), although more weakly (Celus et al, ).…”

“…Pectins, such as HG and RGI, chelate divalent cations (e.g., Ca 2+ , Cu 2+ , Fe 2+ , Mg 2+ , and Zn 2+ ) (Celus et al, ). Pectins also chelate monovalent cations (e.g., K + ), although more weakly (Celus et al, ). Thus, the lower Ca and K content of the Cs98 seeds is consistent with significantly less SCM (Fig.…”

“…Both RGI and HG form ionic cross‐links with Ca 2+ salt bridges, with RGII covalently bonding with boron (Macquet et al, ; McKenna et al, ). Pectins chelate divalent cations such as Ca 2+ , Zn 2+ , Fe 2+ , Mg 2+ , Cu 2+ , Pb 2+ , Sr 2+ , As 2+ , Cd 2+ , and La 2+ , with HG being more extensively studied than RGI or RGII (Celus et al, ). Pectins also chelate monovalent cations, although more weakly than divalent cations (Celus et al, ).…”

“…Pectins chelate divalent cations such as Ca 2+ , Zn 2+ , Fe 2+ , Mg 2+ , Cu 2+ , Pb 2+ , Sr 2+ , As 2+ , Cd 2+ , and La 2+ , with HG being more extensively studied than RGI or RGII (Celus et al, ). Pectins also chelate monovalent cations, although more weakly than divalent cations (Celus et al, ). The stiffness and rheological properties of the hydrogel are dependent upon ionic bonding between pectin molecules and Ca 2+ (Western et al, ).…”