Antioxidant property and storage stability of quince juice phenolic compounds.
The aim of this study was to characterise, in depth, 11 quince cultivars to provide data for their industrial processing into high-quality juices. Polyphenolic composition analyses (identification and quantification), soluble fraction of procyanidins, antioxidant capacity assays and cluster analysis were measured. A total of 19 kinds of polyphenolic compounds were the following in the juices: before and after 6 month of storage time at 4 and 30 °C. Large variations in polyphenolic compounds content were found as affected by quince cultivar. The total phenolics determined by UPLC ranged from 4045 mg to 721 mg/100 mL of juices, and was high correlated with antioxidant activity. During 6 months of storage a significant change was observed in the content of polyphenols, especially in procyanidins (37% and 55%, respectively). This result may be useful for the juice industry as a starting point for the development of tasty quince juices with high levels of bioactive compounds.