Tissue-specific metabolomics and pigment profiling of Black Change and red Chal tomatoes

This study compared two Korean tomato cultivars, the black-pigmented Black Change tomato (BCT) and the red Chal tomato (RT), using tissue-resolved metabolomics and pigment analysis to clarify determinants of peel color and antioxidant potential. Untargeted UPLC-ESI-QTOF-MS profiling was integrated with external-standard quantification of naringenin chalcone and lycopene. BCT peel exhibited lower total phenolic/flavonoid contents and lower antioxidant capacity than RT peel, whereas cultivar differences in flesh and seeds were minor. RT peel contained more naringenin chalcone (6.68 vs 0.56 mg g^-1 in BCT peel) and higher lycopene (426.88 vs 328.62 μg g^-1), while rutin was more abundant in BCT. Pigment profiling showed strong chlorophyll retention in BCT, with chlorophyll a reaching 952.78 μg g^-1 in peel, which likely masks carotenoids and produces the blackish appearance. Overall, the superior nutritional quality often attributed to BCT was not supported and BCT peel coloration is primarily associated with chlorophyll retention.