Flavonoid content of selected foods - A comparison of four international composition tables

The content of flavonoids, widely found in plant-based foods, might differ depending on which food composition table (FCT) is being used. In this study, we investigated the variation and comparability in the flavonoid content of selected foods across four international food composition tables. Flavonoid estimates were derived for all foods available in each table, and comparisons were carried out for foods common between tables. Bias percentage, 95% limits of agreement, and intra-class correlation coefficients (ICCs; 95% confidence intervals [95 %CI]) were estimated. Phenol-Explorer and Indian FCT showed moderate level of agreement for total flavonoid (ICC 0.50 and 0.57 respectively) when compared to the USDA table. eBASIS for total flavonoids and anthocyanidins (ICC 0.67 and 0.85, respectively), and Indian FCT for flavanols and flavanones (ICC 0.71 and ICC 0.85, respectively) showed moderate-to-good level of agreement, and low level of agreement for other subclasses when compared to Phenol Explorer. Several flavonoid subclasses showed low to moderate levels of agreement between FCTs, whilst others (including total flavonoid intake) had lower levels of agreement. Methodological approaches in the measurement of flavonoid content of foods across tables, and continued efforts to improve harmonization of these databases would contribute to improve quantification of flavonoid content.