The hardness of the ice cream samples was evaluated using the penetration test with the aid of a texturometer. The maximum force (g) required to penetrate the ice cream is shown in Fig. 3. The use of a TG concentration of 4 U g1 protein led to an ice cream sample with less firmness in relation to the control sample (without TG). The strengthening of the protein network produces a uniform and stable emulsion and reduces the formation of ice crystals during storage (El-Nagar et al., 2002). The presence of TG results in the formation of a more cohesive protein network through the milk protein polymerization, and this probably leads to a decrease in ice crystallization, reducing the hardness of the ice cream