Effect of calcium concentration on textural properties of high and low acyl mixed gellan gels

✍ Scribed by Yiqun Huang; Juming Tang; Barry G. Swanson; Barbara A. Rasco

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 176 KB
• Volume: 54
• Category: Article
• ISSN: 0144-8617
• DOI: 10.1016/j.carbpol.2003.08.006

✦ Synopsis

Textural properties of 1% low and high acyl gellan gels and their mixtures were studied using compression tests and the microcentrifugemicrofiltration based water holding capacity (WHC) method. Low acyl (1% LA), high acyl (1% HA) gels and mixtures of 1% 25/75 LA/HA, 50/50 LA/HA, 75/25 LA/HA gels with calcium concentrations ranging from 2 to 80 mM were studied. HA or mixed gels with a lower LA/HA ratio had a greater WHC and failure strain than that of LA or mixed gels with a higher LA/HA ratio. Gellan gels with a higher LA/HA ratio had a larger initial Young's modulus. Our study also indicates that a higher LA/HA ratio does not necessarily result in a gel with a larger failure stress, although LA gels are generally firmer than HA gels. Gel strength and WHC of HA and LA/HA mixtures may reflect both stabilization and destabilization effects of glycerate groups positioned at one of the glucose residues in each repeating tetrasaccharide unit of HA gels.