菜籽分离蛋白-卡拉胶轭合物-花椒精油Pickering乳液的构建及其理化性质分析

Fabrication of rapeseed protein isolate-carrageenan conjugate--pepper essential oil Pickering emulsion and analysis of its physicochemical properties

为促进花椒精油和菜籽蛋白的开发利用,采用热诱导法制备了菜籽分离蛋白(RPI)-卡拉胶轭合物纳米颗粒,并以此为乳化剂制备Pickering乳液负载花椒精油。通过单因素试验和响应面试验优化了RPI-卡拉胶轭合物-花椒精油Pickering乳液的制备条件。对制备的RPI-卡拉胶轭合物-花椒精油Pickering乳液的类型、微观结构、热稳定性、贮藏稳定性进行了表征,并考察了其抑菌活性。结果表明:RPI-卡拉胶轭合物-花椒精油Pickering乳液最佳制备条件为RPI-卡拉胶轭合物纳米颗粒添加量0.95%、花椒精油与大豆油混合物(体积比2∶3)添加量50.6%、水相pH9.8,在此条件下包封率为92.34%。制备的RPI-卡拉胶轭合物-花椒精油Pickering乳液为水包油型,其在20~60℃范围内具有较好的稳定性,但在60℃以上不稳定。经过30d贮藏,乳液乳滴粒径变化较小。乳液具有良好的乳滴特征,为稳定性提供了物理基础。与花椒精油和大豆油的混合物相比,RPI-卡拉胶轭合物-花椒精油Pickering乳液在作用受试菌42h前具有相似的抑菌效果,但在42h后表现出更强的抑菌效果。综上,RPI-卡拉胶轭合物-花椒精油Pickering乳液包封率较高,且具备优越的热稳定性、贮藏稳定性和抑菌活性。

In order to promote the development and utilization of pepper essential oil and rapeseed protein,rapeseed protein isolate(RPI)-carrageenan conjugate nanoparticle was prepared by thermal induction method,and Pickering emulsion was prepared to load pepper essential oil from this material.The preparation conditions of RPI-carrageenan conjugate-pepper essential oil Pickering emulsion were optimized by single factor experiment and response surface methodology.The type,microstructure,thermal stability and storage stability of the prepared RPI-carrageenan conjugate-pepper essentia1l oil Pickering emulsion were characterized,and its antibacterial activities were investigated.The results showed that the optimal conditions for the preparation of RPI-carrageenan conjugate-pepper essential oil Pickering emulsion were obtained as follows:dosage of RPI-carrageenan conjugate nanoparticle 0.95%,dosage of pepper essential oil-soybean oil mixture(volume ratio 2:3)50.6%,and aqueous phase pH 9.8.Under these conditions,the encapsulation rate was 92.34%.The prepared RPI-carrageenan conjugate-pepper essential oil Pickering emulsion was oil-in-water type,which had good stability at 20-60℃,but was not stable above 60°℃C.After 30 d storage,the average particle size of the emulsion changed litle.The emulsions had good milk droplet characteristics,which provided a physical basis for stability.Compared with the blend of pepper essential oil and soybean oil,the RPI-carrageenan conjugate-pepper essential oil Pickering emulsion showed similar antibacterial effect within 42 h of action on the subject bacteria,but showed stronger antibacterial effect after 42 h.In conclusion,RPI-carrageenan conjugate-pepper essential oil Pickering emulsion has higher encapsulation rate and superior thermal stability,storage stability and antibacterial activity.