Effect of flavorzyme‐modified soy protein on the functional properties, texture and microstructure of Mozzarella cheese analogue

Abstract

Functional properties, texture, and microstructure of the cheese analogues prepared with adding soy protein which was partially hydrolyzed by flavourzyme were investigated through measurement of meltability, stretchability, texture profile analysis, and SEM images. Degree of hydrolysis (DH) and SDS-PAGE were used to characterize the extent of hydrolysis. DH generally increased with increasing hydrolysis time and addition of enzyme, and it came to 15.1% at the optimum hydrolysis condition (50℃, 0.5w/v% enzyme, 6 hr), at which the soy proteins were hydrolyzed into peptides with the molecular weight less than 31 kDa. Furthermore, the analogue cheese showed favorable stretchability and meltability of 95 and 32 mm (diameter), respectively at the optimum hydrolysis condition. Thirdly, hardness and springiness of cheese analogues generally increased and adhesiveness decreased with partially hydrolyzed soy proteins addition. Lastly, microstructures of cheese analogues from SEM images were used to illustrate the difference in texture and stretchability of cheese analogue products. Practical applications Soy protein hydrolysates with defined degree of hydrolysis were desirable for certain applications, and therefore, the hydrolysis process must be carefully controlled. So comprehensive research on the enzyme hydrolysis conditions was very essential. The outcome of present study could enhance the application of flavorzyme in hydrolysis of soy protein, and therefore facilitated the usage of soy protein hydrolysate in cheese analogue products. Furthermore, the founding in the study also provided a reference to modify the texture and stretchability of cheese, and will do a favor to formulate the cheese analogue products with desired physicochemical properties.