Enhancing of phenolic compounds and antioxidant capacities of Gastrodia elata extract using pruning residues as an agro by–product of Maclura tricuspidate twig

This study investigated the potential of Maclura tricuspidata twig (MTT), an agro–industrial by–product, to enhance the bioactive compounds and antioxidant properties of Gastrodia elata rhizome (GER). GER was co–extracted with MTT at different mixing ratios, and the resulting changes in polyphenolic composition and antioxidant activities were evaluated. HPLC analysis revealed that GER was rich in p –hydroxybenzyl methyl ether ( p –HBME) and parishin (Pa) derivatives, whereas MTT contained diverse polyphenolic compounds with parishins derivatives. With increasing proportions of MTT, the contents of parishin derivatives and flavonoids significantly increased ( p < 0.05), accompanied by marked increases in total phenolic content (TPC) and total flavonoid content (TFC). Furthermore, antioxidant activities measured by DPPH and ABTS radical scavenging assays and FRAP activity increased significantly with increasing of mixing ratio of MTT. These findings indicate that MTT can serve as a valuable by–product for enhancing the phytochemical composition and antioxidant capacity of GER.