改性大豆分离蛋白在黑胡椒油树脂复凝聚微胶囊制备中的应用

将大豆分离蛋白(soybean protein isolate,SPI)与木糖按不同质量比混合,于90℃下反应6 h,得到美拉德反应改性的SPI,再以改性SPI和壳聚糖为复合壁材,通过复凝聚法制备黑胡椒油树脂微胶囊,研究改性SPI对黑胡椒树脂微胶囊包埋效果、热稳定性等性质的影响。结果表明,当SPI/木糖质量比为2∶1时,黑胡椒油树脂微胶囊的包埋效率、产率及80℃下加热8 h后的保留率最高,分别为67.8%、72.07%和75.06%。热重分析表明,与天然SPI相比,改性SPI进一步提高了黑胡椒油树脂微胶囊的热稳定性,扫描电镜分析则表明改性SPI使微胶囊的微观结构更加致密;气相色谱-质谱分析表明利用改性SPI-壳聚糖制备的黑胡椒油树脂微胶囊对烯类挥发性成分的保持能力增加。本研究为拓展SPI的应用领域、提高黑胡椒油树脂微胶囊的稳定性提供参考。

The application of modified soybean protein isolate on the microencapsulation of black pepper oleoresin through complex coacervation

In this work, soybean protein isolate (SPI) was mixed with xylose in different mass ratios and then allowed to react at 90oC for 6 h to yield the Maillard reaction-modified SPI. The resultant Maillard reaction products were collected and used to microencapsulate black pepper oleoresin through coacervation with chitosan. The effects of SPI to xylose mass ratio in the Maillard reaction on the microencapsulation performance and thermal stability of the resultant microcapsules were studied. The results indicated that the SPI to xylose mass ratio of 2:1 contributed to the highest microencapsulation efficiency, microencapsulation yield, and oleoresin retention against the 8h-storage in 80oC, with values of up to 67.8%, 72.07% and 75.06% respectively. Compared with native SPI, the modification greatly improved the thermal stability and microstructure compactness of the microcapsules according to thermogravimetric analysis and scanning electron microscope observation. Gas chromatographic-mass spectrometry showed that the microcapsules prepared with Modified SPI was more effective in retaining volatile compounds especially alkenes. This work provides a theory basis for extending the application of SPI and increasing the stability of black pepper oleoresin microcapsules.