Correlation of two anthocyanin quantification methods: HPLC and spectrophotometric methods

The pH differential method and HPLC are commonly used methods by researchers and the food industry for quantifying anthocyanins in a sample. This study was conducted to establish a relationship between the two analytical methods. Seven juice samples containing an array of different individual anthocyanins were analyzed by pH differential and HPLC (two different columns and mobile phase conditions). In general, total anthocyanins were greater when expressed as malvidin-glucoside than as cyanidin-glucoside, despite the method used. This paper demonstrates the high correlation (R ⩾ 0.925, p ⩽ 0.05) between the pH differential method and HPLC (both systems) when determining the amount of anthocyanins found in samples. For laboratories that do not have the capability for HPLC analysis, the pH differential is a simple and economical method to determine total anthocyanins. This study also demonstrates the importance of reporting the standard used to express the values. There is still a need for both methods and certified anthocyanin standards.