南瓜籽油Pickering乳液的制备及其稳定性研究

Study on the preparation and stability of pumpkin seed oil Pickering emulsion

为了提高南瓜籽油在应用中的稳定性,减少使用化学合成乳化剂带来的潜在毒性,通过p H循环法制备大豆分离蛋白(Soy Protein Isolate,SPI)-单宁酸(Tannic acid,TA)纳米颗粒,接着选择了最佳比例的SPI-TA纳米颗粒作为乳化剂制备南瓜籽油Pickering乳液。进一步研究了乳化剂添加量、南瓜籽油体积分数对乳液表征的影响。结果表明:SPI与TA的复合比例为3∶1(质量比)、乳化剂添加量为2%(以水的质量为基准)、油体积分数为70%时,乳液具备良好的物理状态以及热稳定性、盐离子稳定性,且在14 d的储藏期内,乳液体系中南瓜籽油的酸价、过氧比值(POV)与硫化巴比妥酸(TBA)含量的上升速率明显低于纯油体系。因此,通过SPI-TA纳米颗粒构建的Pickering乳液体系可以有效减缓南瓜籽油的氧化酸败速率。

In order to improve the stability of pumpkin seed oil in application and reduce the potential toxicity caused by chemical synthetic emulsifiers,Soy Protein Isolate(SPI)-Tannic acid(TA)nanoparticles were prepared by pH cycling method.Then the best ratio of SPI-TA nanoparticles were selected as emulsifier to prepare pumpkin seed oil Pickering emulsion.The effects of the addition amount of emulsifier and the volume fraction of pumpkin seed oil on the characterization of the emulsion were further studied.The results showed that when the compounding ratio of SPI and TA was 3∶1(mass fraction),the addition amount of emulsifier was 2%(based on water mass),and the oil volume fraction was 70%,the emulsion had good physical state,thermal stability,and salt ion stability.And during the storage period of 14 days,the increase rate of the acid value,POV and TBA content of pumpkin seed oil in the emulsion system was significantly lower than that of the pure oil system.Therefore,the Pickering emulsion system constructed by SPI-TA nanoparticles can effectively slow down the oxidative rancidity rate of pumpkin seed oil.