Extraction of protein from high-temperature peanut meal using combination process with steam flash-explosion,alkaline-extraction and acid-precipitation

A combined process with steam flash-explosion,alkaline-extraction and acid-precipitation was used to extract protein from high-temperature peanut meal.Through single factor and orthogonal test,the optimum conditions were figured out.Firstly,the high-temperature peanut meal was soaked in 0.3% sulfuric acid solution at 60℃ for 2h,then drained it and washed with water to remove the acid solution remained in the surface of the meal.The pretreated meal was treated with steam flash-explosion at 1.6MPa for 5min.The protein in the steam flash-exploded meal was extracted by alkaline-extraction and acid-precipitation process.The optimal condition for alkaline-extraction was solid to water ratio:1∶12(g/mL),pH9.5,60℃ and 2h.Under these conditions,the protein extraction rate reached 52.6%,which was 10.8% higher than conventional alkaline extraction and acid-precipitation process.The water holding capacity,emulsifying activity index,foaming capacity and foaming stability of the protein extracted using this combined process were significantly improved,which increased by 67.1%,141.0%,131.3% and 107.4% respectively.R esults showed that the combined process with steam flash-explosion,alkaline-extraction and acid-precipitation was appropriate for extracting protein from high temperature peanut meal,which could increase the protein extraction rate and also improve the functional properties.