**Abstract**

This research aimed to evaluate the effects on the antioxidative capacity of cow and goat milk during fermentation with *Lactobacillus acidophilus* LA-5*.* The antioxidative capacity of milk samples during 28 days of storage was measured using a spectrophotometric decolorization assay by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Also a principal component analysis (PCA) was used, to study the development of antioxidative activity during storage, and the connection to proteolysis and peptide concentration. The results of this study suggest that milk type (cow or goat) was a significant parameter for the proteolytic and antioxidative activity of fermented milk. Additionally, high degree positive and negative correlations were observed between the variables analyzed (0.511–0.787).

**Keywords:** probiotics, bioactive peptides, proteolysis, fermented milk, DPPH radical assay
