## 3 Results and Discussion
### Effect of Different Sterilization Methods on Lipid Metabolites in Red Raspberry Juice
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Retention** & **Precursor** & **Product** & **Index** & **Chemical Name** & **Ionization** & **HHP** & & & & & **HIST** & \\
**Time (min)** & **Ions** & **Ions (Da)** & **Index** & **Chemical Name** & **Model** & **VIP** & **FC** & **Variation** & **VIP** & **FC** & **Variation** \\ \hline
3.69 & 126.10 & 96.00 & pmb0302 & 2-aminoethyl phosphate & [M + H]+ & 1.30 & 2.21 & up & & 1.32 & 2.07 & up \\
6.77 & 440.10 & 184.50 & pmb0862 & \multicolumn{1}{c}{Lysophosphatidylcholine 121} & [M + H]+ & & & & 1.14 & 0.48 & down \\
6.95 & 318.30 & 60.10 & pmb2221 & 4-hydroxy phosphosine & [M + H]+ & & & & 1.34 & 0.31 & down \\
7.54 & 309.00 & 209.00 & pmb2289 & 13-hydroxyacetacetination acid & \(\rm{M}-H\)– & & & & 1.04 & 0.40 & down \\
7.55 & 309.10 & 209.00 & pmb2291 & 13-hydroxyacetination acid & \(\rm{M}-H\)– & 1.30 & 0.50 & down & 1.07 & 0.45 & down \\
7.60 & 353.30 & 261.10 & pmb2791 & 9-Hydroxyacetination acid & \(\rm{M}-H\)– & 1.30 & 0.50 & down & 1.07 & 0.45 & down \\
7.60 & 694.10 & 353.70 & pmb0160 & \multicolumn{1}{c}{Monetarylyceride (18:13) isomer 5} & [M + H]+ & 1.24 & 0.44 & down & 1.04 & 8.23 & up \\
7.71 & 518.20 & 184.10 & pmb0865 & \multicolumn{1}{c}{Lysophosphatidylcholine 183} & [M + H]+ & & & & 1.34 & 2.94 & up \\
7.88 & 494.30 & 184.20 & pmb0848 & \multicolumn{1}{c}{Lysophosphatidylcholine 161} & [M + H]+ & & & & 1.33 & 2.20 & up \\
2.85 & 520.00 & 184.50 & pmb0873 & \multicolumn{1}{c}{Lysophosphatidylcholine 182} & [M + H]+ & & & & 1.32 & 2.92 & up \\
8.42 & 293.00 & 275.00 & pmb2786 & \multicolumn{1}{c}{\(\rm{9-Hydroxyacetination acid}\)} & [M + H]– & & & & 1.34 & 0.01 & down \\
8.45 & 353.30 & 261.40 & pmb1645 & \multicolumn{1}{c}{Monetarylyceride (acyl 18:3) isomer 3} & [M + H]+ & 1.14 & 0.35 & down & 1.25 & 2.71 & up \\
8.73 & 452.30 & 255.20 & pmb0160 & \multicolumn{1}{c}{Lysophosphatidylethanolamine 160} & [M - H]– & & & & 1.34 & 0.18 & down \\
8.74 & 452.00 & 255.30 & pmb3117 & Lysophosphatidylcholine 160 & \(\rm{M}-H\)– & 1.26 & 0.39 & down & 1.34 & 0.14 & down \\
8.80 & 496.30 & 184.20 & pmb0855 & \multicolumn{1}{c}{Lysophosphatidylcholine 160} & [M + H]+ & & & & 1.33 & 0.45 & down \\
8.80 & 496.30 & 184.00 & pmb0132 & \multicolumn{1}{c}{Lysophosphatidylcholine 160} & [M + H]+ & & & & 1.33 & 0.45 & down \\
8.91 & 522.40 & 184.00 & pmb0859 & \multicolumn{1}{c}{Lysophosphatidylcholine 181} & [M + H]+ & & & & 1.34 & 2.04 & up \\
8.91 & 524.10 & 184.00 & pmb2388 & \multicolumn{1}{c}{Lysophosphatidylcholine 180} & [M + H]+ & & & & 1.34 & 2.19 & up \\
8.91 & 544.40 & 485.20 & pmb0060 & \multicolumn{1}{c}{Lysophosphatidylcholine 204} & [M + H]+ & & & & 1.34 & 2.16 & up \\
8.96 & 295.00 & 277.30 & pmb2778 & 9.10-Epoyn octadecination acid & \(\rm{M}-H\)– & & & & 1.33 & 0.37 & down \\
9.34 & 510.10 & 184.40 & pmb2406 & Lysophosphatidylcholine 1720 & [M + H]+ & & & 1.33 & 0.27 & down \\
9.86 & 482.10 & 341.70 & pmb0883 & Lysophosphatidylcholine 180 & [M + H]+ & & & 1.33 & 0.17 & down \\
9.91 & 524.40 & 184.00 & pmb0136 & \multicolumn{1}{c}{Lysophosphatidylcholine 180} & [M + H]+ & & & 1.34 & 0.17 & down \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The metabolized lipids identified in red respberry juices after different sterilization treatments. Correlation Analysis of Key Aromas of C6 Aldehydes in Red Raspberry Juice and Fatty Acid Metabolic Pathways  
To further elucidate the intrinsic relationship between the loss of C6 aldehydes and fatty acid metabolism pathways during red raspberry juice sterilization, we performed a correlation analysis involving hexanal /(Z)-3-hexneal, key enzymes, downstream aroma substances, fatty acid composition, and differentially metabolized lipids. As presented in Figure 6, the changes in the abundance of hexanal and (Z)-3-hexneal induced by sterilization treatments were significantly associated with 27 and 34 substances, respectively, with the top 25 correlated substances for each shown in Figure 7a, Figure 7b, respectively.