Relationships between skin flavonoid content and berry physical-mechanical properties in four red wine grape cultivars ( Vitis vinifera L.)

•Texture properties and flavonoids content were measured in 4 wine-grape cultivars.•Functions to estimate flavonoids from texture data were developed using MARS.•Relations between berry physical-mechanical parameters with flavonoids were found.•Cultivar-specific functions reached higher accuracy than the multi-cultivar one.