Gel strength estimation and optimizing textural behavior of mixed gelatin–carboxymethylcellulose hydrogel

Abstract Rheological and textural behavior of mixed hydrolgels gelatin‐carboxymethylcellulose (CMC) were examined to evaluate the influence of hydrogel concentration (0.5, 0.75, and 1.0%), hydrogel mixed ratio (1:2, 1:1, and 2:1), temperature (4, 12, and 20 °C) and pH (3, 5, and 7.0) on gel strength. Depending on the experimental design, chemical weak and physical mixed gelatin‐CMC hydrogels were obtained according to small amplitude oscillation (SAOS) test. The most effective factor was found as pH followed by hydrogel mixed ratio and hydrogel concentration for gel strength according to design model. The optimum textural conditions for mixed hydrogels were also determined to be 1.0% of hydrogel concentration, 2:1 of hydrogel mixed ratio, 4 °C of temperature, and pH of 7.0 with texture of 1.30 N. It is concluded that gel strength is more sensitive to temperature from rheological measurement than from getting textural measurements. Practical applications Hydrogel is a good film form to resist water vapor and air diffusion in coating for fruit and vegetables. Combination of different hydrogels is increased rheological properties such as gel strength due to the synergistic interactions. Thus, gel strength estimation is a critical issue to be explored in food industry especially in food coatings for the improvement of texture, stability, and shelf life extension of food products. As a consequence, there is need to evaluate stability of gel strength under different gel production and processing conditions.