Unveiling metabolome heterogeneity and new chemicals in 7 tomato varieties via multiplex approach of UHPLC-MS/MS, GC-MS, and UV-Vis in relation to antioxidant effects as analyzed using molecular networking and chemometrics

Tomatoes show diverse phytochemical attributes that contribute to their nutritive and health values. This study comprehensively dissects primary and secondary metabolite profiles of seven tomato varieties. UHPLC-qTOF-MS assisted molecular networking was used to monitor 206 metabolites, 30 of which were first-time to be reported. Flavonoids, as valuable antioxidants, were enriched in light-colored tomatoes (golden sweet, sun gold, and yellow plum) versus high tomatoside A, an antihyperglycemic saponin, in cherry bomb and red plum varieties. UV-Vis analysis revealed similar results with a strong absorbance corresponding to rich phenolic content in light varieties. GC-MS unveiled monosaccharides as the main contributors to samples' segregation, found abundant in San Marzano tomato accounting for its sweet flavor. Fruits also demonstrated potential antioxidant activities in correlation to their flavonoids and phospholipids. This work provides a complete map of tomatoes' metabolome heterogeneity for future breeding programs and a comparative approach utilizing different metabolomic plat-forms for tomato analysis.

Automated summary

This study comprehensively analyzed the primary and secondary metabolites of seven tomato varieties, discovering 30 newly reported substances. Light-colored tomatoes were found to be rich in valuable antioxidants, flavonoids, while red tomatoes contained tomatoside A, an antihyperglycemic saponin. Spectral analysis showed high phenolic content in light tomatoes. GC-MS analysis revealed that monosaccharides were the main contributors to tomato composition, with San Marzano tomatoes having abundant monosaccharides, which explains their sweet flavor. This study provides a complete map of the metabolome heterogeneity of tomatoes for future breeding programs.