Abstract: In order to explore the mechanism of color formation of roast duck, pigment was extracted ultrasonically and separated by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). In addition, the structure of the pigment was identified by ultraviolet visible (UV-VIS) spectroscopy and Fourier transform infrared spectroscopy (FT-IR). The results showed that the brightness value (L*) of roast duck skin decreased, and both the redness value (a*) and yellowness value (b*) increased with the increase of roasting time. The UV-VIS spectrum showed a maximum absorption peak at 210 nm. The FT-IR spectrum showed that the pigment contained at least six compounds with functional groups of –OH, C=O, –NH2, –CHO and high conjugated C=C , whose molecular masses were 365.11, 301.14, 277.22, 303.23, 353.27, and 279.23 respectively. These constituents included long-chain fatty acid esters, oligomers, redox reaction products, derivatives produced by lipid oxidation, amides and aldehydes.

Key words: roast duck skin pigment; high performance liquid chromatography; mass spectrometry; ultraviolet-visible spectroscopy; Fourier-transform infrared spectroscopy