## 2 Results
To identify the metabolic pathways with the most significant effects on the different nonvolatile metabolites, the intersection of the five pathways with the most significant differences in the three comparison groups were obtained, which identified two common metabolic pathways, namely the citrate cycle (TCA cycle) and galactose metabolism (Figure 5D). There were two (arginine biosynthesis; ascorbate and aldarate metabolism), three (glycine, serine and threonine metabolism; starch and sucrose metabolism; and amino sugar and nucleotide sugar metabolism) and two (aminoacyl-tRNA biosynthesis; and glyoxylate and dicarboxylic acid metabolism; and amino  
dicarboxylate metabolism) unique metabolic pathways in the ZKH1H vs. CFD, ZKH1 Hvs. ZKH13H, and ZKH13H vs. CFD comparison groups, respectively (Figure 5D). A total of 55 VOCs were detected in the peanut samples. The majority of these compounds were present in all three samples (Table S4) as follows: organic oxygen compounds (24.1%); organoheterocyclic compounds (20.4%); organic nitrogen compounds (13%); organic acids and their derivatives (13%); lipids and lipid-like molecules (11.1%); benzoids (11.1%); hydrocarbons (3.7%); and homogeneous non-metallic compounds (3.7%) (Figure 6A). To explore the differences between the metabolites of the peanut varieties, the sample data were subjected to a principal component analysis (PCA) (Figure 6B). The data points of the three groups of peanuts were clearly distinguished on the score plot. After normalization of the metabolite data, cluster analysis was performed on all the samples. Cluster analysis classifies metabolites with the same characteristics into groups and identifies the degree of variation in the levels of metabolites with the same characteristics within a group. The results revealed that there were different clustering patterns among the different varieties (Figure 6C). Figure 6: Multivariate statistical analysis of VOCs in the three varieties of peanut samples. (**A**) Classification of the 55 nonvolatile metabolites detected in the three varieties of peanut samples. (**B**) PCA score plot. (**C**) Heatmap analysis. Figure 7: Differential VOCs obtained by comparison of each pair of varieties. Score plots of OPLS-DA pairwise comparisons of differentially abundant metabolites in (**A**) ZKH1H vs. CFD, (**D**) ZKH1H vs. ZKH13H, and (**G**) ZKH13H vs. CFD. Volcano plots showing the differential nonvolatile metabolite expression levels in (**B**) ZKH1H vs. CFD, (**E**) ZKH1H vs. ZKH13H, and (**H**) ZKH13H vs. CFD. Correlation analysis of differential volatile metabolites in (**C**) ZKH1H vs. CFD, (**F**) ZKH1H vs. ZKH13H, and (**I**) ZKH13H vs. CFD. Also, KEGG pathway analyses of the differentially abundant VOCs between the pairwise comparisons were also performed via the KEGG database, and the significant differences in each comparison group are shown in Figure 8. In the ZKH1H vs. CFD comparison, the following five metabolic pathways were significantly enriched (\(p<0.\) 05): nitrogen metabolism; pyruvate metabolism; glycolysis/gluconeogenesis; glyoxylate and dicarboxylate metabolism; and glycine, serine and threonine metabolism (Figure 8A). There were no significant differences in metabolic pathways in the ZKH13H vs. CFD comparison. In the ZKH1H vs. ZKH13H comparison, the following two metabolic pathways were significantly enriched: nitrogen metabolism and glycine; and serine and threonine metabolism.