Effect of heating on oleosins and extrinsic proteins from soybean oil bodies

Effect of heat treatment of soybean seed and different p H value of raw soybean milk on oleosins and extrinsic proteins from soybean oil bodies were studied, and oleosins and extrinsic proteins were characterized by SDS-PAGE. The conclusions were demonstrated as three points. When soybean seed of imbibition and raw soybean milk were treated by heat, the endo protease activity of P34 was inhibited with increasing of temperature and time. Consequently, it was benefical for oleosin keeping at oil body and the effect of heat treatment on soybean seed of imbibition was more remarkable than raw soybean milk. Extrinsic proteins (including glycinin, conglycinin, and allergic protein of Bd 30K) were gradually hydrolyzed from oil body with increasing of heat treated strength and p H when raw soybean milk with different p H walues was heated. The purity of oil body and content of Bd 30 K were 97% and under 1% respectively when oil body was prepared from raw soybean milk at 80℃, p H8.5, and 5³0min.