Abstract:

To investigate the differences of eight organic acids in raspberry from different origins, a method for measuring the content of eight organic acids at the same time by HPLC was established, in order to provide a theoretical basis for some sour substances in raspberry. The raspberry herb of the same harvesting period was taken as the research object, the quantitative methods of eight organic acid components were established by HPLC, and the differences were analyzed and compared by cluster analysis (CA), principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). The results showed that the linear relationship of organic acids in the concentration range of 0.001-2.00 mg/mL was good, the limit of detection (LOD) were 0.326~1.114 μg/mL, the limit of quantification (LOQ) were 1.060~3.604 μg/mL, the average recovery rates were 97.40%-101.58%, and the relative standard deviation (RSD) were 1.23%-2.34%. This method determines the content of organic acids in raspberry of different origins, both cluster analysis and OPLS-DA can effectively distinguish some production areas according to provinces, and the effect of OPLS-DA is better than CA, the origins can be clustered into 7 categories according to the province: Zhejiang, Anhui, Jiangsu, Fujian, Jiangxi, Sichuan and Hunan. The PCA results showed that oxalic acid, tartaric acid, malic acid, shikimic acid, citric acid, succinic acid, and acetic acid were the main organic acids in raspberry herbs. HPLC was established to analyze the differences on the content of eight organic acids in raspberry at the first time, and the origins are wide, the results are reliable, which could be used for the quality evaluation and preliminary differentiation of organic acid components in raspberry of different origins.

Key words: raspberry, different origins, multivariate statistics, organic acids, HPLC