Extraction and characterization of protein from cold pressed and traditional pressed degreased walnut dregs

To optimize the extraction conditions of protein from the degreased walnut dregs, and make rational use of protein of cold pressed walnut dregs and traditional pressed walnut dregs, the single factor and the orthogonal experiment were used in the present study, also the characteristics of proteins extracted from traditional pressed walnut dregs and cold pressed walnut dregs were also investigated. The results show that the optimum extraction conditions were: SLR 1:8, temperature 60℃, pH 9.0, time 60 min and the extraction yield was 78.13 % under these conditions. The functional properties results of proteins extracted from cold pressed walnut dregs and traditional pressed walnut dregs revealed that both of them were highly soluble in the range of pH, water absorbency, oil absorbency were up to (5.60±0.30) g/g for CPWP, (4.27±0.16) g/g for TPWP and (5.70±0.28) g/g for CPWP, (6.59±0.21) g/g for TPWP, respectively. In addition, both of CPWP and TPWP were good digestive properties in vitro without significant difference.