Physical Modification Of The Soybean Protein Concentrate By Alcohol Extraction

The soybean protein concentrate (SPC) was produced from low-denatured and degreased soybean powder, and extracted by ethanol precipitation. The effects of soybean powder particle size, alcohol concentration, reaction temperature, reaction time and solid-to-liquid ratio on the solubility of SPC were studied. The optimal conditions was determined by the perpendicular experiment as follows:soybean powder particle size 100 mesh, reaction time 1h, ethanol concentration 65%, the ratio of solid to liquid 1:4 and reaction temperature 50℃.Then SPC was used to prepare high solubility product by two physical modification methods, including water bath heating and microwave heating.In the water bath heating modification, the effects of heating temperature, heating time and materials thickness on the SPC properties of water absorption, oil absorption, emulsification and foamability were investigated. Results showed that the foamability of SPC was the most and its enhancement was most obvious among the several properties when the heating conditions was:temperature 50℃, heating time 60s and materials thickness 3mm, and the improvement of water absorption was the most when the heating conditions was as follows:temperature 70℃, heating time30s and material thickness 3mm.In microwave heating modification, the effects of microwave power, reaction time and materials thickness on SPC properties of water absorption, oil absorption, emulsification and foamability were investigated Results showed that microwave heating treatment could not improve the oil absorption of SPC. Then the improvement of foamability was significant at the conditions of microwave power 650w, reaction time 90s and materials thickness 3mm.