Effect of Potassium Ions on the Properties and Mechanism Analysis of Tamarind Gum/Kappa-Carrageenan Composite Gel

Abstract

To investigate the effect of K+ on the properties and mechanism of the composite gel system consisting of tamarind gum and κ-carrageenan, four methods including rheology, texture analysis, microstructure, and infrared spectroscopy were used to investigate the properties and structure of the composite gel with different K+ additions. The rheological results showed that the addition of K+ increased the modulus of the gel system and decreased the compliance and total deformation. When the addition of K+ increased to 15 mmol/L, the apparent viscosity reached its highest value of 2690 Pa·s. The results of texture analysis revealed that the strength and hardness of the gel system increased with the addition of K+, but its elasticity and cohesiveness decreased relatively. Infrared spectroscopy and microstructure demonstrated that K+ could promote the interaction between tamarind gum and κ-carrageenan, the gel pores tend to be dense and uniform, and the inter-pore walls were most regular and strong at the K+ addition of 15 mmol/L. The results showed that the addition of K+ could make the gel system exhibit better viscoelasticity and anti-deformation, and make the network structure more compact, which would provide a theoretical reference for the application of tamarind gum and κ-carrageenan in compounding.

Keywords

• tamarind gum
• κ-carrageenan
• gel properties
• microstructure
• gelation mechanism