Ultra-high Pressure Assisted Preparation Of α-lactoalbumin Phospholipid Complex And Its Application In Cheese

Alpha-lactalbumin is rich in tryptophan,lysine,cysteine and other essential amino acids,which can improve the humoral immune function,regulate appetite,promote sleep,relieve pain,reduce blood pressure and other effects.In this paper,the preparation of alphalactalbumin and soybean soft phospholipid complex emulsion is assisted by ultra-high pressure assisted technology,and added to cow’s milk.After fermentation,fresh cheese rich in alpha-lactalbumin phospholipid complex is prepared.The alpha-lactalbumin phospholipid complex can increase the content of alpha-lactalbumin in cheese,improve the quality of fresh cheese,and provide a theoretical basis for the development of fresh cheese with higher nutritional value and better quality.The results of this study are as follows:1.Preparation of alpha-lactalbumin phospholipid complex assisted by ultra-high pressureAlpha-lactalbumin phospholipid complex was prepared by ultra-high pressure auxiliary treatment.Based on the evaluation rate of binding rate,on the basis of single-factor experiment,the response surface analysis method was used to optimize the ultra-high pressure preparation conditions of alpha-lactalbumin phospholipid complex,and the best process conditions for ultra-high pressure treatment of Alpha-lactalbumin phospholipid complex were: 265 MPa ultra-high pressure,15 min holding pressure treatment time,25 ℃treatment temperature.2.Characterization and binding mode of the alpha-lactalbumin phospholipid complexThe particle size,surface hydrophobicity,total sulfhydryl group,quenching method and binding method of alpha-lactalbumin phospholipid complex were studied.The results showed that the average particle size of alpha-lactalbumin phospholipid complex was 486.4nm,and the distribution was uniform.For static quenching,there is a clear hard core structure under the transmission microscope.The bonding effect is good.The bonding method is mainly related to the hydrogen bond and the hydrophobic force.3.Effect of the addition of alpha-lactalbumin phospholipid complex on the quality of fermented milk and cheeseThe titration acidity,water holding capacity,rheological properties,texture characteristics and quality evaluation of fresh cheese prepared by adding alpha-lactalbumin phospholipid complex fermented milk were studied.The results showed that the addition of 2.4% alphalactalbumin phospholipid complex after ultra-high pressure treatment increased the titrated acidity of fermented milk,promoted the growth and proliferation of lactic acid bacteria,increased the water retention of fermented milk,and strengthened the tight network inside the complex.The structure,chewy hardness and elasticity of cheese made from fermented milk have also been greatly improved.The content of alpha-lactalbumin has been improved,effectively improving the nutritional value of fresh cheese.