| Peony seed protein was prepared by alkaline extraction and acid precipitation from peony seed meal which was dehulled then defatted by supercritical carbon dioxide extraction. The extraction conditions of peony seed protein were optimized by response surface methodology on the basis of single factor experiment, and the functional properties of peony seed protein were studied and compared with soybean protein isolate（SPI）. The results showed that the optimal extraction conditions of peony seed protein were obtained as follows: ratio of material to liquid 1∶25, extraction pH 9.25, extraction temperature 53.32℃ and extraction time 6874 min, and the sequence of the factors influencing the protein extraction rate from high to low was: extraction pH, ratio of material to liquid, extraction time, extraction temperature; under the optimal conditions, the extraction rate and content of protein reached 6295% and 6806%, respectively; the emulsion stability and foam stability of peony seed protein were better than those of SPI, while the water absorption, oil absorption, water binding capacity, emulsifying ability and foamability were poorer than those of SPI. |
