Corn gluten hydrolysis by Alcalase: Calibration of pH-stat

In the present study, pH-stat method was calibrated by TNBS and OPA reactions for control of hydrolysis of corn gluten by Alcalase. Hydrolysis experiments were conducted in a batch reactor at the temperature of 50 °C for various pH values, and at pH 7 for 40 and 60 °C. The calibration was characterized by good linear correlations for both methods. The mean pK values of corn gluten hydrolysates were obtained as 6.83, 6.59 and 6.36 for 40, 50 and 60 °C, respectively.

Research highlights▶ pH-stat method was calibrated for control of hydrolysis of corn gluten by Alcalase. ▶ The extent of hydrolysis reaction increased with increase on temperature and pH. ▶ The calibration was characterized by linear correlations for TNBS and OPA methods. ▶ The pK values obtained by both methods were found almost same. ▶ The pK values were found as 6.83, 6.59 and 6.36 for 40, 50 and 60 °C, respectively.