The microwave digestion method was optimized to extract amino acids from Chebulae Fructus (CF), and the differences of amino acids in CF from different origins and different processing states were analyzed and evaluated. The amount of total amino acid extraction of CF was used an indicator, the influences of digestion temperature, digestion time, and liquid-material ratio on extraction effect were investigated by sing factor test and response surface method (RSM), and the extraction conditions were optimized. The contents of 17 amino acids were determined by an automatic amino acid analyzer. Chemometrics was also applied to analyze the differences in amino acid content between CF from different origins and processing states. The optimal digestion conditions were a digestion temperature of 150 ℃, a digestion time of 18 min, and a liquid-material ratio of 65:1 (mL:g). Under these conditions, the total amino acid content of CF could reach 19.72 mg/g. According to the standards published by FHO/WHO, CF from Lincang city of Yunnan province and unprocessed CF were considered to have higher nutritional value. The results of chemometric analysis showed that there were significant differences in the amino acid content in CF between Guangxi province, Dehong prefecture of Yunnan province and Lincang city of Yunnan province, and six differential amino acids between the three origins were screened out. There were also significant differences in the amino acid content of CF before and after processing, and eight differential amino acids were screened out. The optimized amino acid extraction method had short time and high efficiency, and there was no significant difference from the conventional digestion method. There were differences in amino acid content of CF from different origins and processing states, which can be analyzed by chemometrics and screened for different components. This study can provide references for the quality evaluation of the producing area, the extraction and content research of amino acids of CF.
