Comparison of several procedures used for the extraction of anthocyanins from red grapes

Several procedures for the extraction of grape anthocyanins, based on different methods described in the literature, have been assayed. Results have shown that the use of solvents containing up to 1% of 12 N hydrochloric acid for the extraction of grape anthocyanins resulted in the partial hydrolysis of malvidin 3-O-acetylglucoside, leading to important changes in the relative content of anthocyanins in those extracts, despite their higher efficiency in extracting total anthocyans in some cases. Nevertheless, the use of different neutral solvents resulted in a similar relative content of anthocyanins in the extracts, and some of them could be as efficient in extracting total anthocyanins as other procedures that used an acid solvent for extraction. These data suggest that the use of solvents containing up to 1% of 12 N hydrochloric acid in the extraction of anthocyanins from grapes or from any other plant material containing acetylated anthocyanins should be avoided, especially if the work is related with any type of taxonomic studies.