An antioxidative peptide was isolated from milk fermented with Lactobacillus delbrueckii subsp. bulgaricus IFO13953 by Sephadex LH-20 gel filtration chromatography and ODS reversed phase partition chromatography. The peptide was analyzed using a mass spectrograph and an amino acid sequencer. The peptide was composed of eleven amino acid residues. The amino acid sequence of the peptide was determined as Ala-Arg-His-Pro-His-Pro-His-Leu-Ser-Phe-Met. Which corresponded with the amino acid arrangement from the 96th to the 106th of kappa -casein of skim milk used as raw material. Therefore, this antioxidative peptide was estimated to be a peptide Formed by the lactic acid fermentation of IFO13953. Although the scavenging activity of DPPH radical of the peptide was lower than BHT, the peptide showed about 5 times stronger antioxidative activity than BHT in the beta -carotene decolorization system.
