The effects of heating, UV irradiation, and storage on stability of the anthocyanin–polyphenol copigment complex

The influences of temperature, UV irradiation, and 3 months of storage (in the presence and absence of light) on the stability of a copigmentation complex were investigated. The copigments selected for the study included: quercetin-5′-sulphonic acid (QSA), sodium salt of morin-5′-sulphonic acid (NaMSA), rutin, quercetin, chlorogenic acid, tannic acid, and unknown flavones from roots of the Chinese origin herb Scutellaria baicalensis Georgi. The copigmentation effect increased with the copigment content. UV irradiation had a stronger degradation effect on the copigmentation complex than heating at 80 °C. Direct sunlight was found to be a significant factor, determining instability of the anthocyanin–copigment complex during storage. The Scutellaria flavones predominated over other copigments.