Impact of different post-harvest processing methods on the chemical compositions of peony root.

The impact of key processing steps such as boiling, peeling, drying and storing on chemical compositions and morphologic features of the produced peony root was investigated in detail by applying 15 processing methods to fresh roots of Paeonia lactiflora and then monitoring contents of eight main components, as well as internal root color. The results showed that low temperature (4 °C) storage of fresh roots for approximately 1 month after harvest resulted in slightly increased and stable content of paeoniflorin, which might be due to suppression of enzymatic degradation. This storage also prevented roots from discoloring, facilitating production of favorable bright color roots. Boiling process triggered decomposition of polygalloylglucoses, thereby leading to a significant increase in contents of pentagalloylglucose and gallic acid. Peeling process resulted in a decrease of albiflorin and catechin contents. As a result, an optimized and practicable processing method ensuring high contents of the main active components in the produced root was developed.