纳米SiO2/大豆分离蛋白为壁材的核桃油微胶囊特性

Characteristics of walnut oil microcapsules with nano-SiO 2/soy protein isolate as wall material

为提高核桃油微胶囊特性,采用纳米SiO 2改性大豆分离蛋白(soy protein isolate,SPI)制备纳米SiO 2/SPI为壁材的核桃油微胶囊。通过考察核桃油微胶囊含水率、吸水率、溶解性、包埋率、色泽、粒径、热稳定性、形态和贮藏稳定性等特性,研究了SPI中纳米SiO 2添加量[1.00%、3.00%、5.00%、7.00%和9.00%(质量分数)]对核桃油微胶囊的影响。结果表明:纳米SiO 2添加量对含水率、吸水率、色泽、形态没有明显影响;纳米SiO 2添加量加3.00%时,核桃油微胶囊的综合性能好,此时包埋率85.35%,溶解性97.80%,粒径11.34μm,熔融温度164.4℃;贮藏12 d后核桃油微胶囊包埋率仅下降了24.71%,过氧化值为10.24 mmol/kg,仅为未添加纳米SiO 2微胶囊的41.72%。POV动力学研究结果表明,核桃油微胶囊氧化动力学适用于一级反应。

In order to improve the characteristics of walnut oil microcapsules,walnut oil microcapsules with nano-SiO 2/SPI as wall material was prepared by modifying soy protein isolate with nano-SiO 2.The effects of nano-SiO 2 addition(1.00%,3.00%,5.00%,7.00%,9.00%)in SPI on walnut oil microcapsules were studied by investigating the characteristics of water content,water absorption,solubility,embedding rate,color,particle size,thermal stability,morphology and storage stability.The results showed that the addition of nano-SiO 2 had no effect on water content,water absorption,color and morphology.At 3.00%of nano-SiO 2 addition,the comprehensive properties of walnut oil microcapsules were better than that of control samples.At this time,the embedding rate and the solubility were 85.35%and 97.80%respectively.The particle size was 11.34μm,and the melting temperature was 164.4℃.After 12 days’storage,the embedding rate of walnut oil microcapsules decreased 24.71%,and POV was 10.24 mmol/kg in which 41.72%of the microcapsules without nano-SiO 2.The results of POV kinetic showed that the oxidation kinetics of walnut oil microcapsules was suitable for the first-order reaction.