Characterization of gellan/gelatin mixed solutions and gels

Abstract

The physico-chemical properties of gellan/gelatin mixed solutions and gels were examined at five different ratios of gellan to gelatin (100:0 (I), 80:20 (II), 60:40 (III), 40:60 (IV), 20:80 (V)) and four different NaCl levels (0–300 mmol/l). All mixed solutions exhibited the shear-thinning behavior, which decreased with increasing gelatin proportion, temperature, and NaCl level. Synergism on G′ was observed in mixed solution III and IV depending on NaCl level. Hardness of mixed gel decreased with increasing gelatin proportion and cohesiveness increased up to the gellan to gelatin ratio of 40–60 and then decreased. For gellan dominant gels, maximum hardness and cohesiveness were observed at NaCl level of 150 mmol/l. Increasing gelatin proportion caused an increase in gel turbidity at lower NaCl levels and a decrease in gel turbidity at higher NaCl levels. In general, WHC increased with increasing gelatin proportion and decreasing NaCl level. Color holding capacity significantly increased with increasing gelatin proportion. Flavor holding capacity increased by adding gelatin and then linearly decreased with increasing gelatin proportion. Therefore, this study suggests that there is an optimum NaCl concentration and gellan to gelatin ratio to enhance the physico-chemical properties of gellan/gelatin mixed solutions and gels.