Abstract:Soybean was rich in protein and polypeptide, of which lunasin was an important functional polypeptide. In this study, the lunasin in six kinds of domestic soybeans was separated and purifiedby SDS-PAGE for the determination of lunasin content in domestic soybeans, and a gel band containing lunasin was obtained, In addition, the specific peptides were analyzed by NanoLC-Obitrap and PRM after enzymatic hydrosis, and the lunasin content was determined. The results showed that content of lunasin was 4.66 mg/g in Wangdou35 (highest content among the six kinds of domestic soybeans) , 2.24 mg/g in Zhonghuang 13, 3.35 mg/g in Zhonghuang 75, 2.59 mg/g in Xu dou14, 2.03 mg/g in Qian Dou 7, and 2.87 mg/g in Heihe 43, indicating that the domestic soybean was rich in lunasin. The proposed method in this study had the advantages of simple pretreatment, good repeatability, accurate result and good linear relationship, which could be used to determine the content of lunasin in soybean and screen the soybean varieties that were rich in lunasin.
