Abstract: L-leucine can be deposited from hydrolysate of pig blood powder when sodium chloride (NaCl) is used as salting-out agent. In the deposition process, the time of salting-out deposition was determined, and influence of the main factors, such as temperature, pH value, and NaCl quantity on deposition efficiency was investigated. The results show that salting-out NaCl in the feed liquid. A low temperature was good for salting-out deposition, so industrial process can carried out at room temperature or low temperature. L-leucine is deposited as dileucine salt and the deposition efficiency reached a maximum when pH value of the solution is about 2 and NaCl was present. The greater the NaCl concentration in the solution, the higher the deposition efficiency. Addition of NaCl was 0.35g/mL in the industrial extraction process.

摘要：

以NaCl为盐析剂从猪血粉水解液中盐析沉淀L-亮氨酸，确定了盐析沉淀所需的时间，考察了温度、pH值、NaCl加入量等因素对L-亮氨酸盐析沉淀率的影响。结果表明：盐析剂NaCl在原料液全溶解后搅拌半小时盐析沉淀率基本上达到最大值；低温对于盐析沉淀是有利的，工业生产中可在室温下或低温下进行；在溶液的pH值约为2时，NaCl存在下L-亮氨酸以二亮氨酸盐酸盐形式析出，沉淀率达到最大；溶液中氯化钠浓度越高盐析沉淀率越高，工业生产上可按0.35 g/mL的比例加入NaCl。室温下控制猪血粉水解液的pH值为2，按0.35 g/mL原料液的比例加入NaCl盐析出二亮氨酸盐酸盐，经精制得L-亮氨酸产品，产品符合《中华人民共和国药典》（2000年版二部）质量标准，L-亮氨酸的平均提取率为82.36%。