Tannin analysis of chestnut bark samples (Castanea sativa Mill.) by HPLC-DAD–MS

• The tannin composition of commercial chestnut bark samples was studied.
• A rapid HPLC-DAD/ESI-MS method was developed.
• The main tannins and other phenols were identified and quantified.
• 1-O-galloyl castalagin was tentatively identified in chestnut bark samples.

In the present investigation, an HPLC-DAD/ESI-MS method for the complete analysis of tannins and other phenolic compounds of different commercial chestnut bark samples was developed. A total of seven compounds (vescalin, castalin, gallic acid, vescalagin, 1-O-galloyl castalagin, castalagin and ellagic acid) were separated and quantified, being 1-O-galloyl castalagin tentatively identified and found for the first time in chestnut bark samples. Thus, this method provided information regarding the composition and quality of chestnut bark samples, which is required since these samples are commercialised due to their biochemical properties as ingredients of food supplements.