Amaranth antioxidant peptides: Activity against free radicals with physiological significance

ORSINI DELGADO MC; GALLEANO M; AÑON MC; TIRONI V

Buenos Aires

Congreso; VIII Meeting of the Society for Free Radical Biology and Medicine - South American Group (VIII SFRBM-SAG; 2013

Society of Free Radical Biology and Medicine-South American Group

The demonstration of beneficial properties of amaranth has increased its appeal to be incorporated into daily food. The aim of this work is to evaluate the antioxidant activity of Amaranthus mantegazzianus peptides. A simulation of gastrointestinal digestion process was performed in a protein isolate and in an extensive hydrolysate with alcalase (pepsin, pH 2, 1h; pancreatin, pH 6, 1h). The antioxidant properties of soluble fraction in a phosphate buffer 35mM pH 7.8 were analyzed: 1) against peroxyl radicals generated from AAPH: ORAC and EPR (PBN as radical catcher); 2) against hydroxyl radicals generated by Fenton reaction: HORAC and EPR (POBN as radical catcher); 3) against superoxide radicals: generated PMS / NADH and NBT oxidation to nitrite; generated by xanthine oxidase and reaction with WST-1 producing WST-1 formazan. The fluorimetric methods were much more sensitive than spectrophotometric and than EPR, although all methods allowed us to observe sequestering activity of the three tested free radicals, increasing due to the action of alcalase or digestive enzymes. These results reaffirm the amaranth protein as an interesting source of active peptides that could be generated in the body through the gastrointestinal digestion.