Antioxidant activity of soluble protein from natural fermented buffalo milk

Curd from buffalo milk, called dadih, is famous fermented milk from West Sumatra, Indonesia. The milk is fermented naturally by relying on microorganisms which exist nature. Dadih is commonly consumed as breakfast or eaten together with rice. This study aimed to determine the antioxidant activities of dadih from different regency in West Sumatra by using ABTS, DPPH and Fe reducing power methods. The soluble protein of dadih was separated from insoluble protein and fat by centrifugation at 11,000 x g. The supernatant was then assayed for protein content and antioxidant activities. The result showed that among dadih from Agam, Sijunjung and Solok regency, dadih from Agam regency showed lowest protein content but highest antioxidant activities in Fe reducing power with absorbance 1.28 and scavenging activity against radical ABTS (86.46%) or DPPH (82.24%). The result indicated that dadih, especially from Agam regency is very potent as an antioxidant.