Characterization of an additional anthocyanin pigment in extracts of strawberries, Fragaria*1, *2

Investigation of the anthocyanin pigments of forty lots of strawberries representing thirteen selections and five varieties revealed the presence of a third pigment in most samples not previously identified. The pigment is not a chromatographic artifact as it is unchanged upon rechromatography. It is composed of pelargonidin and glucose in a 1:1 molar ratio. During acid hydrolysis the pigment readily forms pelargonidin-3-glucoside as an intermediate before pelargonidin formation. Infrared and ultraviolet-visible spectral properties eliminate the possibility of acylation with organic acids. Radiotracer experiments eliminate the possibility of incorporation of methanol as an ether or acetal into the pigment. On the basis of spectral data, chromatographic properties, and hydrolysis experiments, it is suggested that the pigment is either the furanose form or the alpha anomer of pelargonidin-3-glucoside.