Abstract: This experiment studied the effect of ultra high pressure treatment on the yields of total antioxidants, phenol, anthocyanins and VC extracted from Lonicera caerulea fruits and the total antioxidant activity of Lonicera caerulea extracts, and also explored the relationship between cellular microstructure and the extraction yield of total antioxidants. Our results showed that the highest yield of total antioxidants of 85.20 mg/g fresh fruit weight was obtained using an extraction pressure of 300 MPa. The lyophilized extracts obtained at 300, 400 and 0 MPa had the highest contents of total phenols, anthocyanins and VC, which were 136.48, 4.12 and 27.14 μg/mg, respectively. The total antioxidants extracted at 400 MPa possessed the highest antioxidant capacity as indicated by the highest 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical (ABTS+·) scavenging capacity (0.37 mmol/L), ferric reducing ability of plasma (FRAP, 0.84 mmol/L) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging capacity (91.5%). Transmission electron microscopy images showed that 400 MPa treatment caused huge damage to the cellular structure of Lonicera caerulea, which could be helpful for the extraction of antioxidants. Significant differences in anthocyanins and VC were observed among some of the groups tested but not among the others. This experiment has proved that ultrahigh pressure processing can promote disruption of Lonicera caerulea fruit cells, being helpful for enhanced solvent extraction and activity of antioxidants.

Key words: Lonicera caerulea, ultra high pressure, antioxidant, cellular structure