Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 6/23/2008
Publication Date: 3/6/2009
Citation: Lee, J., Rennaker, C.D., Wrolstad, R.E. 2009. Comparison of two methods for anthocyanin quantification. Acta Horticulturae. 810:831-834.
Interpretive Summary: This study examined commonly used methods (HPLC and the pH differential methods) for determining the anthocyanin content of samples. Anthocyanins are the compounds that give small fruits and their processed products red, blue, and black colors. The two methods examined had a high correlation with one another. The pH differential method is a good alternative for labs that do not have access to an HPLC for quantifying anthocyanin content. Detailed findings from this study were presented at the conference.
Technical Abstract: The pH differential method (AOAC method 2005.02) by spectrophotometer and high performance liquid chromatography (HPLC) are methods commonly used by researchers and the food industry for quantifying anthocyanins of samples or products. This study was carried out to establish a relationship between these two frequently utilized analytical methods. Seven juice samples, each containing an array of individual anthocyanins, were analyzed by pH differential and HPLC (two different conditions). Additional samples that had been processed in the lab were also included in the comparison (n > 180). This study demonstrated a high correlation (R > 0.925, p = 0.05) between the pH differential method and HPLC (both systems) when determining the amount of anthocyanins within samples. In both methods, total anthocyanins were greater when values were expressed as malvidin-3-glucoside than as cyanidin-3-glucoside. For laboratories that do not have the capability for HPLC analysis, the pH differential offers a straightforward and economical method to determine total anthocyanins. This study also demonstrated the importance of reporting the standard used to express the values. Methods and certified anthocyanin standards are critical for anthocyanin research and the food industry.