Extraction and analysis of antioxidant compounds from the residues of Asparagus officinalis L.

Asparagus residues were used as materials to obtain antioxidant compounds by solid-liquid extraction in this study. The effects of different extraction parameters including extraction solvents, time, temperature and liquid-solid ratio on the contents of total flavonoids, total phenolics and total antioxidant activity were investigated. Antioxidant activity of the extract from asparagus residues was evaluated by HPLC- ABTS · (+) and the bioactive components were identified by HPLC- MS/MS. The results showed that the extraction yield was significantly influenced (P < 0.05) by solvent composition, extraction time and temperature. The appropriate parameters were preferred as extraction solvent of 50 % ethanol with liquid-solid ratio of 30:1, extraction temperature of 80 °C and time of 2 h. Antioxidant activity evaluation of the extract indicated flavonoids and phenolics were dominant bioactive compounds. Five antioxidant compounds were identified as ferulic acid, kaempferol, quercetin, rutin and isorhamnetin.