Dynamic Characterization of Antioxidant-Related, Non-Volatile, and Volatile Metabolite Profiles of Cherry Tomato During Ripening

TL;DR

This study tracks changes in cherry tomato metabolites during ripening, revealing how nutritional and sensory qualities develop.

Contribution

The paper provides a comprehensive, stage-specific metabolite profile linking ripening to antioxidant and sensory traits in cherry tomatoes.

Findings

Ripening increases lycopene, glucose/fructose, and antioxidant vitamins (A, E, C) while decreasing sucrose and bitter steroidal glycoalkaloids.

Non-volatile metabolites like phenolic acids and flavonoids accumulate at red-ripe stage, enhancing nutritional quality.

Volatile compounds shift toward fruity-floral odorants during ripening, with esters and terpenoids dominating the volatilome.

Abstract

Cherry tomato is a notable dietary source of metabolites associated with antioxidant functions. However, how ripening reshapes primary, specialized, and volatile metabolites remains incompletely resolved. Green-ripe and red-ripe fruits were comparatively analyzed using targeted HPLC assays for quality indices and vitamins, UPLC–MS/MS for non-volatile metabolites, and HS-SPME–GC–MS for volatiles. Ripening was accompanied by a pronounced accumulation of lycopene and an increase in soluble solids, reflecting a shift of sugars toward glucose and fructose while sucrose remained low. Organic acids declined overall, with citric acid remaining predominant. The free-amino-acid pool expanded, with redistribution from GABA toward glutamate and aspartate. Vitamins exhibited stage-dependent patterns; antioxidant-related vitamins (A, E, and C) were higher at the red-ripe stage, indicating a compositional enhancement relevant to nutritional quality. Non-volatile metabolomics revealed 618 differentially accumulated metabolites, with phenolic acids, flavonoids, alkaloids, amino acids, and lipids as major classes. Phenolic acids and flavonols, dominated by hydroxycinnamoyl-quinic acids and quercetin/kaempferol glycosides, accumulated at the red-ripe stage, whereas steroidal glycoalkaloids decreased, suggesting conversion away from bitter or anti-nutritional constituents. GC–MS profiling identified 788 volatiles, with esters, terpenoids, and ketones contributing more than half of the volatilome. Ripening favored fruity–floral odorants such as β-ionone and (5Z)-octa-1,5-dien-3-one, while reducing green-leaf aldehydes. These stage-specific shifts in metabolite composition jointly define the sensory and nutritional maturation of cherry tomato. The identified metabolite markers provide a foundation for evaluating fruit maturity and guiding breeding toward improved quality attributes.

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