Changes in Chromatographic Profile of Anthocyanins of Red Onion During Extraction

The role of acidifying agent in extracting anthocyanins from red onions was investigated. Cl^- of HCl disrupted complex structures present in onion tissue to release anthocyanins and also induced formation of other complexes containing the pigment. Formate did not produce these effects. A schematic was developed to illustrate the interaction and decomposition of anthocyanin fractions during HCl extraction. The implications of the presence of Cl^- in the extractant on interpretation of extraction results were discussed. Anthocyanins possibly acylated with non-cinnamic acids were considered to be particularly affected by mineral acids in the extractant.