Evolution of colour and phenolic compounds during Garnacha Tintorera grape raisining

摘要: Abstract The off-vine drying is one of the most important steps in production a high quality naturally sweet wine. However, only few studies have analyzed changes colour and phenolic compounds grapes throughout process. In this work, UV/Vis spectrophotometry HPLC/DAD-ESI/MS were applied to determine, respectively, evolution red Garnacha Tintorera during raisining total water loss 83 days was about 62% sugar concentration rose from 225 464 g L −1 . Browning low-medium molecular weight increase dehydration CIELab coordinates, decreases ∗ (red/green) lightness increases b (yellow/blue), saturation hue angle. general, determined (anthocyanins, flavonols, esters hydroxycinnamic acids, flavan-3-ol monomers proanthocyanidins) but lesser extent than expected because drying. lower observed for hydroxicinnamic acids suggesting these could undergo strong enzymatic degradation. Despite this, both terminal extension subunit compositions show little changes, while mean degree polymerization proanthocyanidins as progresses.