CHANGES OF ANTIOXIDANT ACTIVITIES OF BAKER’S AND ACTIVE DRY YEASTS DURING INCUBATION
ANGEL ILIEV*, SVETOSLAV ALEKSANDROV, DIMITRIA KOZAREKOVA-YOVKOVA
Vasil Aprilov str. 154, Food research and development institute Plovdiv
*Corresponding author: a.iliev@canri.org
Keywords: antioxidant activities (AOA), autolysates, baker’s and active dry yeast
Abstract: The objective of the present study was to investigate changes of antioxidant activities of yeast autolysates obtained from three strains (two from baker’s yeast, and one from active dry yeast) which has been incubated at 25°C and 37°C. Antioxidant activity has been measured at 24h, 32h, 48h, and 56h. Three different methods for measuring antioxidant activity has been used: radical scavenging activity assay against 2,2-diphenyl-1-picrylhydrazyl used as a source of free radicals, inhibition of Cu2+ induced lipid oxidation, and Fe2+ chelating activity. The active, dried yeasts developed higher antioxidant activity at 24h, but at the later measurement the rate of increasing of their antioxidant activity is significantly lower than of instant baker’s yeasts. Some of the strains reached maximum of their antioxidant activities between 32 and 48h, until other continue to develop antioxidant activity, even at the end measurement point of the incubation.