Abstract:Total acid titration has a guiding effect on microbial inhibition and seasoning during the production of condiments.Titration of the total acid of the condiment sample with sodium hydroxide standard solution，and the operation error caused by the different titration speed is different on the determination results.In order to reduce the error caused by personal error during the titration process，the automatic total acid titration system was designed by using the nonlinear predictive control strategy of delay compensation.The system makes full use of the titration curve model to optimize the titration process in different stages，and to achieve automatic adjustment of titration speed.It was confirmed that the good titration effect was obtained in the repeated determination of multiple sets of samples.