Comparison of Essential Oils of Houttuynia cordata Thunb. from Different Processing Methods and Harvest Seasons Based on GC-MS and Chemometric Analysis

Figure 4

PCA analysis and OPLS-DA analysis of DHC and FHC and their two harvest seasons. PCA score plot for DHC and FHC (a). OPLS-DA score plot and the corresponding validation plots based on 200 times permutation tests of the OPLS-DA model for DHC and FHC (b, c), for DHC1 and DHC2 (d, e), and for FHC1 and FHC2 (f, g).

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