This study investigated how enzymatically modified lysozyme added to yogurt can improve its antioxidant activity and quality properties during cold storage. For this purpose, hen egg white native lysozyme (LZ) was hydrolyzed with trypsin, creating a functional tryptic lysozyme hydrolysate peptide (LZT). The obtained hydrolysate exhibited the highest antioxidant activity compared to native Lysozyme. The LZ and LZT were added in 0.4% concentration to yogurt made (YLZ and YLZT, respectively). The treated yogurt and control groups were stored at 4 ◦C for 28 days, and their antioxidant activity, sensory, physicochemical, and microbiological properties were analyzed. The result showed that the antioxidant, sensory properties, physicochemical, and microbiology of the yogurt with LZT were improved compared to yogurt treated with LZ and the control sample after 28 days of storage. In conclusion, the findings of this study suggested that yogurts enhanced with LZT may serve as functional food products with significant health benefits.