Abstract: The Black-bone silky fowl melanin (BSFM) was degraded with K₂CO₃-H₂O₂, KMnO₄, NaOH-H₂O₂ and NH₃·H₂O-H₂O₂ oxidative degradation methods to afford water-soluble products.The identities and molecular weight distributions of the degradation products were analyzed and the degradation yields of different methods were calculated.Results showed that products from different degradation methods were different.The degradation yield of KMnO₄-degradation method was up to 82.5%, followed by K₂CO₃-H₂O₂ method with 61.5%, the degradation yields of the rest two methods were also above 50%. As to the molecular weight of degradation products,NH₃·H₂O₂-degradation products was the biggest and up to 12265.5 Da, the degradation degree was least,the types and quantities of NH₃·H₂O-H₂O₂-degradation products was also less than the other three methods.On the other hand,with the strong acidic environment,KMnO₄ oxidation degradation degree of BSFM was largest.It further proved that in the strong acidic and/or basic conditions melanin was more easily to be oxidized and hence degraded.

Key words: black-bone silky fowl melanin, oxidative degradation, molecular weight, GC-MS