Study on condition optimization of extracting proteins from highland barley by alkaline

Crude protein from highland barely powder was prepared by the method of alkali extraction and acid precipitation. With the extraction rate of crude protein as an index, the effects of NaOH concentration, materialliquid ratio, extraction temperature and time on the extraction were investigated. The extraction condition was optimized by orthogonal experiment. The results showed that the factors affected the extraction of proteins from highland barley in the predominant order of NaOH concentration, material-liquid ratio and extraction temperature.When the extraction time was 1.0h, an optimum extraction condition for the crude protein was obtained, that was, NaOH concentration of 0.15%, material-liquid ratio of 1∶12g/mL and extraction temperature of 55℃. The precipitation pH value of proteins from highland barely was 4.5. Under the above conditions, the extraction rate of crude protein from highland barely and its protein content was 72.36% and 83.35%, respectively.