Preliminary analysis of primary and secondary factors of γ-aminobutyric acid enrichment in fermentation process of Sojae Semen Praeparatum / 中草药

ABSTRACT

Objective: To study the primary and secondary factors of γ-aminobutyric acid (GABA) enrichment in the processing of Sojae Semen Praeparatum (SSP), and lay the foundation for revealing the formation mechanism of high content of GABA in SSP. Methods: The dynamic changes of pH value, temperature, moisture, protease and glutamic acid decarboxylase (GAD) in the processing of SSP were determined by conventional methods. The GABA content of each sample was determined by pre-column on-line derivatization established by our laboratory. The correlation between each indicator and GABA was analyzed by SPSS software. Results: Correlation analysis and multiple regression analysis showed that the correlation coefficient between water, acid protease and GABA was 0.211 and -0.340, respectively, and the P values were 0.324 and 0.228, respectively. The correlation was small and there was no statistical difference. The absolute value of the regression coefficient showed that the primary and secondary status of other indicators in the formation of GABA was pH value (-0.375) > temperature (-0.284) > GAD (0.140) > alkaline protease (0.047) > neu-protease (-0.030), in which pH value, temperature and neutral protease had a negative correlation with GABA, and GAD activity and alkaline protease had a positive correlation with GABA. Conclusion: The temperature, pH value, GAD, neutral and alkaline protease are important factors affecting the formation of GABA in the fermentation process of SSP.