Abstract:

Porcine plasma protein solution (4%, W/W) was hydrolyzed for 0.5 to 5 h with alcalase. Then antioxidant activities of hydrolysates were evaluated through the assay of reducing power and direct free radical scavenging activity using electron spin resonance (ESR) spectrometer. The results showed that the reducing power of protein hydrolysates increases with the increase of degree of hydrolysis (DH) (p ＜ 0.05), and the scavenging activities of the hydrolysates on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·), hydroxyl radical (·OH) and superoxideanion radical (O2·) also increase with the increases of hydrolysis time and protein concentration (p ＜ 0.05). Although the intact porcine plasma protein shows an antioxidant effect, it is far less than hydrolyzed porcine plasma protein. In conclusion, the antioxidant activity of the alcalase-hydrolyzed porcine plasma protein is dependent on its DH and protein concentration, and it may be a potential antioxidant in food industry.

Key words: antioxidant activity, porcine plasma protein, enzymatic hydrolysis, electron spin resonance (ESR)