Study of UV–Vis molar absorptivity variation and quantitation of anthocyanins using molar relative response factor.

• The structural impact on anthocyanins' UV–Vis molar absorptivity was studied; • A quantitative strategy based on the molar relative response factors was proposed; • An online database for 617 anthocyanins was developed to support the approach; • Our strategy provided improved quantitative results for anthocyanins in food. The effects of anthocyanin's substitution groups on the UV–Vis molar absorptivity were examined by analyzing a group of 31 anthocyanidin/anthocyanin reference standards with ultra-high performance liquid chromatography-diode array detector (UHPLC-DAD). The substitution groups on aglycones were found to associate with molar absorptivity variations, often neglected in anthocyanin quantitation, resulting in significant analytical errors. A simple yet comprehensive strategy based on the molar relative response factors (MRRFs) and a single master reference calibration (i.e., cyanidin-3-glucoside) was proposed to quantify anthocyanins in red cabbage, blueberry, and strawberry samples with improved analytical accuracy. The results indicate this approach provides an effective, inexpensive, and accurate analytical method for anthocyanins in food materials without using individual reference standards. MRRFs of 617 anthocyanins/anthocyanidins were calculated, and the information is freely available at https://BotanicalDC.online/anthocyanin/. This study could be critical to developing new reference methods for anthocyanin analysis and harmonizing results and data from various sources. [ABSTRACT FROM AUTHOR]