Antioxidant Activity of Gamma-Irradiated Asparagus cochinchinensis (Asparagi radix) (Lour.) Merr. Extract and Inhibition Effect on Lipid Oxidation of Emulsion-Type Pork Sausage

The objective of this study was to determine the antioxidant activity of gamma- irradiated Asparagus cochinchinensis (Asparagi radix) (Lour.) Merr. Extract (ARE) and its inhibition effect on food lipid oxidation using emulsion-type pork sausage as a model. ARE was prepared from dried Asparagi radix root and ARE solution (1.0 g/mL) was gamma-irradiated with designated doses at 5, 10, and 20 kGy. Antioxidant activity of ARE solution was determined by measuring 1,1-diphenyl-e-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-9-sulphonic acid) (ABTS) radicals. Activities of DPPH and ABTS radicals were decreased, whereas total phenolic contents increased after gamma irradiation with a dose dependence. Addition of gamma-irradiated ARE dose-dependently retarded lipid oxidation of emulsion-type pork sausage during storage at 4℃. These results indicated that gamma-irradiated ARE might have antioxidant activity more than non-irradiated ARE due to increase of the content of polyphenolic compounds by ionizing radiation.