The anthocyanins of apples and pears: The occurrence of acyl derivatives

The major pigment in red peel of some apple cultivars was confirmed as cyanidin 3‐galactoside and minor pigments identified were cyanidin 3‐glucoside, 3‐arabinoside and 3‐xyloside as well as acylated derivatives of all four glycosides. The minor fractions which were separated by paper chromatography varied in composition according to the methods of extraction and purification. The efficiency of their extraction was increased by the use of sulphur dioxide in the extracting medium (acetone). Possible loose association of anthocyanins and proanthocyanidins was indicated, and the instability of the latter during gel filtration with an acid solvent was demonstrated. Minor pigments were negligible in the pears examined. Some further criteria of anthocyanin purity are suggested.