Contents of extractable and non-extractable polyphenols in the leaves of blueberry
A. Cheng, X. Chen, W. Wang, Z. Gong, L. Liuhttps://doi.org/10.17221/272/2012-CJFSCitation:Cheng A., Chen X., Wang W., Gong Z., Liu L. (2013): Contents of extractable and non-extractable polyphenols in the leaves of blueberry. Czech J. Food Sci., 31: 275-282.
The contents of extractable polyphenols (EPP), non-extractable polyphenols (NEPP), extractable proanthocyanidins (EPAC), non-extractable proanthocyanidins (NEPAC) and extractable anthocyanidins (EAC) in blueberry leaves were investigated. An experiment was conducted to analyse the effect of solvent types (methanol and ethanol), concentration (50 and 70%) and pH (2 and 6) on the extraction of bioactive compounds. Total extractable polyphenols (TEPP), total extractable proanthocyanidins (TEPAC), and total extractable anthocyanidins (TEAC) were analysed in methanol/ethanol/water extracts, NEPP were determined in acidic hydrolysates and NEPAC were quantified by depolymerisation in HCl/butanol. The results showed that ethanol and methanol did not affect the extraction of TEPP, while methanol was better for TEPAC and TEAC. The contents of TEPP and TEAC in 50% solvent were higher than those in 70% solvent. When solvent pH dropped to 2, the contents of EPP and EPAC were increased, while the EAC content was decreased.Keywords:
leaves of blueberry; extractable polyphenols; non-extractable polyphenols; proanthocyanidins; anthocyanidins