桃仁分离蛋白颗粒的制备及其乳化性能研究

Study on the preparation and emulsifying properties of peach seed protein isolate nanoparticles

使用碱溶酸沉法对桃仁分离蛋白(PSPI)进行提取,然后采用pH循环法制备PSPI纳米颗粒,并以蛋白颗粒为乳化剂制备乳液,发现该颗粒具有优异的稳定Pickering乳液的能力。颗粒的大小为300 nm左右,并随着pH的变化而发生不同程度的聚集。通过调节溶液的pH可以改变PSPI的润湿性,并且整个体系在pH=2.0和8.0时表现出接近中性的润湿性。流变性表明乳液是假塑性流体,具有类凝胶性质。在这些pH下乳液具有优异的离心稳定性和储存稳定性,可以形成油相体积分数为80%甚至87%的高内相乳液。而且,该高内相乳液对离子浓度有很高的抗性,可以在盐浓度为1 mol/L的条件下稳定存放一个月。这些结果表明,桃仁分离蛋白颗粒是一个绿色且性质优越的乳化剂,在食品、化妆品以及石油工业中具有潜在应用。

Peach seed protein isolate(P S P I)was prepared by alkali extraction with isoelectric precipitation.The composition of the PSPI was determined,and the protein content was approximately 91.2%.When the pH is below the isoelectric point,the particles are positively charged,and conversely,when the pH is above the isoelectric point,the particles are negatively charged.PSPI nanoparticles were prepared by pH-cycling method,and they exhibited excellent stabilization for Pickering emulsions.The size of the particles is around 300 nm,and they aggregate to different degrees with the change of pH.The wettability of PSPI nanoparticles could be adjusted simply by changing the pH of solutions,and the system shows a neutral wettability at pH 2.0 and 8.0.However,when the pH value is 5.0,the particles have strong hydrophobicity.The rheological properties indicate that the emulsion is pseudoplastic fluid with gelatinous properties.At pH 2.0 and 8.0,the emulsions have outstanding stability,and moreover,stable high internal phase Pickering emulsions(HIPPEs)with internal oil phase fraction of 80%and even 87%were obtained.In addition,such HIPPEs have good resistance to ionic strength,which can remain stable at high salt concentration up to 1 mol/L for over 1 month.These findings show that PSPI nanoparticles are green and excellent emulsifier,which have potential applications in food,cosmetic,and petroleum industries.