Preparation Process Optimization and Quality Analysis of Processed String Cheese

String cheese, valued for its ease of peeling and convenience, represents an emerging form of cheese product. However, current products are predominantly based on natural cheese and suffer from drawbacks such as inconsistent hand-tear properties and poor stretchability. Therefore, developing a high-quality processed string cheese with stable tearability and a well-defined fibrous structure is a major technical requirement that the industry faced. Natural Mozzarella cheese was used as raw material and sensory score was taken as the evaluation index, both the ingredient formulation and processing technology were optimized through single-factor experiments. The result showed that the optimal formulation consisted of 60% mass fraction natural Mozzarella cheese, 10% mass fraction skim milk powder, 0.6% mass fraction emulsifying salt, 7.5% mass fraction coconut oil, and 0.5% mass fraction citric acid, with the rest being water. The optimal processing parameters were molding temperature of 75 ℃, fixed molding time of 8 min, and six cycles of blanching and stretching. Through determination and analysis of tensile strength, texture profile, microstructure, and degree of texturization, the processed string cheese achieved the highest sensory score under the optimized formula and process conditions. The optimized sample exhibited a tensile strength of 0.39 MPa and a texturization degree of 6.47, both significantly higher than those of commercially available products, and demonstrated superior fibrosity and hand-tear properties. Compared with commercial samples, the optimized product showed stable quality with lower hardness, while comparable springiness, chewiness, and cohesiveness, with stable overall quality. The combination of blanching stretching treatment and formulation optimization promoted the orderly alignment of casein, resulting in a dense fibrous network structure. This research provided a feasible technical pathway for the development of high-quality processed string cheese with stable hand-tear properties and excellent fibrous structure.