基于主成分分析和聚类分析的发酵虫草菌粉类产品氨基酸比较研究

Comparative study on amino acids of fermented Cordyceps powder products based on principal component analysis and cluster analysis

目的分析不同发酵虫草菌粉类产品氨基酸的含量差异,结合聚类分析和主成分分析法评价发酵虫草菌粉类产品的质量。方法采用氨基酸自动分析仪测定氨基酸含量,色谱柱为LCA K06/Na离子柱,流动相为柠檬酸钠0.06 mol/L(pH 3.45)(A)-柠檬酸钠0.1 mol/L(pH 10.85)(B),梯度洗脱:0~3.5 min,100%A;3.5~11.0 min,85%A;11.0~17.0 min,80%A;17.0~23.5 min,67%A;23.5~28.0 min,20%A;28.0~45.0 min,100%B,体积流量为0.45 m L/min洗脱泵+0.25 m L/min衍生泵;检测波长440 nm(脯氨酸)+570 nm(其余氨基酸);温度为58~74℃梯度控温,进样50μL,外标法测定氨基酸含量。结果分别对3种发酵虫草菌粉类产品A、B、C中氨基酸进行含量测定,产品A总氨基酸质量分数为251.82~265.93 mg/g,产品B总氨基酸质量分数为279.67~333.40 mg/g,产品C总氨基酸质量分数为321.37~370.86 mg/g,样品各批次间一致性较好。产品A和产品B为同一原料药,氨基酸含量差异不明显,产品C中组氨酸和精氨酸含量与产品A和产品B存在较大差异。主成分分析筛选的前3个主成分的累积方差贡献率达到93.551%,包含了各样品中氨基酸含量的大部分信息。聚类分析将30批样品聚为2类,其中产品A和产品B聚为一类,产品C聚为一类,聚类分析结果与实际情况相符。变量聚类分析表明当氨基酸变量聚为5类时,随机选择其中的5个变量能够准确反映发酵虫草菌粉氨基酸的质量。结论通过氨基酸含量差异研究,能够有效区别不同发酵虫草菌粉类产品,结合主成分分析和聚类分析能够客观评价发酵虫草菌粉类产品的质量。

Objective To analyze the differences in amino acid content of different fermented Cordyceps powder products, and evaluate the quality of fermented Cordyceps powder products by combining cluster analysis and principal component analysis. Methods Automatic amino acid analyzer was used to determine the content of amino acid. The column was LCAK06/Na Ionic column with mobile phase A（trisodium citrate, 0.06 mol/L, pH 3.45） and mobile phase B（trisodium citrate, 0.10 mol/L, pH 10.85） at a flow rate of 0.45 m L/min elution pump and 0.25 m L/min derivative pump by gradient elution（around 3.5 min, 100%A; 3.5—11.0 min, 85%A; 11.0—17.0 min, 80%A; 17—23.5 min, 67%A; 23.5—28 min, 20%A; 28—45 min, 100%B）; The detection wavelength was 440 nm for proline and 570 nm for the remaining amino acids; The temperature was set at 58—74 ℃as gradient temperature control, and the injection volume was 50 μL. The content of amino acid was determined by external standard method. Results The content of amino acids in three products of fermented Cordyceps powder was detected, and the total content of amino acid were 251.82—265.93 mg/g in product A, 279.67—333.40 mg/g in product B, and 321.37—370.86 mg/g in product C, respectively. The consistency between batches of samples was good. Product A and product B were the same active pharmaceutical ingredient, and the difference in amino acid content was not obvious. The content of histidine and arginine in product C was quite different from that of product A and product B. The cumulative variance contribution rate of the first three principal components of the principal component analysis screening reached 93.551%, which contains most of the information of the amino acid content of each sample. The cluster analysis clustered 30 batches of samples into two categories, in which product A and product B were grouped together, and product C was grouped into one group. The cluster analysis results were consistent with the actual situation. Variable cluster analysis showed that the five variables randomly selected could accurately reflect the quality of amino acid the fermented Cordyceps powder when the amino acid variables were clustered into five categories. Conclusion According to the comparative study on the differences in the content of amino acid, different fermented Cordyceps powder products can be effectively distinguished. The combination of principal component analysis and cluster analysis can objectively evaluate the quality of fermented Cordyceps powder products.