Impact of diverse mineral hardness in electrodialysis water on the ionotropic gelation mechanism of low methoxyl pectin

Abstract

In this study, the effect of desalinated lava seawater via electrodialysis (ED water) on the formation and properties of low methoxyl pectin (LMP) gels was investigated. Additionally, the syneresis, microstructure, gelation mechanism, and thermostability of the gel samples were analyzed. When the ED water content exceeded 25 %, pectin gels with viscosities and textures that differed from those of the sol were formed. The highest gel hardness (9.38 N) was observed when 50 % ED water was mixed with LMP. However, when 75 % ED water was added, the pore size of the LMP gel became the largest, and excess water was released from the gel, resulting in a weak gel strength (4.98 N). The formation and properties of the gel structure were found to be mainly due to the ionic bonds between the minerals in the ED water and the free carboxyl groups of pectin, and it was confirmed that the hydrogen bonds within the pectin chains also had an effect. These results suggest that the interaction between the ED water and LMP can be widely used in various industrial fields, including low-sugar gels or viscosity-enhancing agents with diverse rheological properties.