Design and optimization of technology for orientation generated indigo in processing of Indigo Naturalis / 中草药

ABSTRACT

Objective: Screening the influencing factors that affect the indigo-generated significantly in processing of Indigo Naturalis, the levels were optimized and combined to obtain the optimum technology for the indigo-generated. Methods: Using an HPLC method for determining indigo in crude Indigo Naturalis and taking indigo content generated from fresh leaf as an index, the significantly influencing factors and the optimal level combination were screened by the statistical methods of Plackett-Burman design and Box-Behnken design response surface analysis. Results: The soaking and making indigo process of Indigo Naturalis was identified as the wax was not removed before soaking, soaking pH value was 3.5, and solvent volume (mL) leaf mass (g) was 13. Soaked in dark at 25 °C for 24 h, and ventilation time of 30 min, then ammonia water was added to adjust pH value to 9. Conclusion: The soaking and making indigo process of Indigo Naturalis could be optimized systematically, it could be used to clarify the various factors on the impact of the active indigo in the process of Indigo Naturalis. At the same time, it could lay the foundation for the study on processing principle of Indigo Naturalis.