Study On Hydrolysis Of Soybean Phosphatide In Aqueous System

Preparation of lysophospholipids by phospholipase A₁-catalyzed hydrolysis of Soybean powder phosphatide, soybean phospholipids and soybean oil sediment were studied in aqueous phase respectively. The acid value was chosen as a measurement of reaction degree according to the principle of enzyme hydrolysis. GC,HPLC were chosen to detect the average molecular weight of phospholipid,and the hydrolysis rate was calculated.The soybean phospholipids was hydrolyzed by phospholipase A₁.Through the single factor experiment and orthogonal experiments, the optimum conditions were determined as follows: reaction temperature 60℃, enzyme dosage 200U·g^-1,reaction time5h,substrate concentration50%.Under the optimal conditions the acid value of product raised83.64mgKOH·g^-1, the hydrolysis rate was 111.8%, the saturated fatty acids content decreased 6.16%.The soybean oil sediment was hydrolyzed by phospholipase A₁.Through the single factor experiment and orthogonal experiments, the optimum conditions were determined as follows: reaction temperature 60℃, enzyme dosage 290U·g^-1,reaction time7h.Under the optimal conditions the acid value of product raised 92.56mgKOH·g^-1, the hydrolysis rate was 118.4%, the saturated fatty acids content decreased 19.29%.The soybean oil sediment was also hydrolyzed by phospholipase A₁ in supercritical CO₂.The effect of temperature,pressure, time,the enzyme dosage on hydrolysis were determined. The optimum conditions were determined by orthogonal experiments as follows: time 4h, pressure 10MPa, temperature 60℃,the enzyme dosage 200U·g^-1. Under the optimal conditions the acid value of product raised 93.96mgKOH·g^-1, the hydrolysis rate was 119.8%, the saturated fatty acids content decreased21.85%.Soybean powder phosphatide was hydrolyzed by phospholipase A₁ in aqueous phase, The effect of reaction temperature, enzyme dosage, reaction time, substrate concentration, rotation speed on hydrolysis were determined. By the single factor experiment and response surface methodology, the optimal reaction conditions were determined as follows: reaction temperature59℃, enzyme dosage196U·g^-1, reaction time8.49h, substrate concentration63.8%,rotation speed554r/min.Under the optimal conditions the acid value of the product raised 75.36mgKOH·g^-1, the hydrolysis rate was 102.1%, the saturated fatty acids content decreased 18.18%.N-acylated phosphatidylethanolamines in soybean powder phosphatide was separated by TLC and analyzed by HPLC,GC,IR,MS. It took : C12:0,C14:0,C16:0 and C18:0 as its side chain fatty acids.