Field-portable analysis of anthocyanin concentration in sepals of Hydrangea macrophylla

Abstract

A field-portable method, adapting commercially available chlorophyll content meters, has been developed to measure the anthocyanin concentration in red and blue sepals of Hydrangea macrophylla. The meters were calibrated to total extractable anthocyanin concentration. The strength of the linear relationship (anthocyanin content index vs. extractable anthocyanin concentration) was better for red than blue sepals, due perhaps to the inclusion of purplish sepals in the blue data set or perhaps to more than one mechanism for the bluing of sepals. The meters were demonstrated to be an effective tool for the measurement of relative anthocyanin concentration in hydrangea sepals as a function of bloom stage.