Anthocyanic pigment determination in red fruit juices, concentrated juices and syrups using liquid chromatography Original Research Article

Determination of free anthocyanins by liquid chromatography has been investigated to improve a method for quality control of these natural products found in eight red fruit juices, concentrated juices and syrups (black currant, elderberry, sour cherry, strawberry, grape, blueberry, raspberry, and red currant). Among the various experimental possibilities, an isocratic simple method using water, acetonitrile and formic acid as eluting mixture has been chosen. Results obtained by nine laboratories concerning the determination of the main anthocyanins contained in strawberry (cyanidin-3-glucoside, 3.9–10.6%; pelargonidin-3-glucoside, 89–95%; and pelargonidin-3-arabinoside, 3.1–3.9%), raspberry (cyanidin-3-glucoside, 16–17% and cyanidine-3-sophoroside, 78–81%), elderberry (cyanidin-3-sambubioside-5-glucoside, 13.4%; cyanidine-3-sambubioside, 47.8% and cyanidin-3-glucoside, 38.6%) and black currant (cyanidin-3-glucoside, 3.9–6.9%; cyanidin-3-rutinoside, 29–39%; delphinidin-3-glucoside, 14–16% and delphinidin-3-rutinoside, 41–52%) juices allowed this new protocol to be studied and tested for reliability using the repeatability and reproducibility criteria.