均质压力及喷雾干燥温度对鱼油微胶囊化的影响

Influence of homogenization pressure and spray drying temperature on microencapsulated fish oil

采用辛烯基琥珀酸酯淀粉Hi-Cap100和葡萄糖浆作为鱼油微胶囊的壁材。研究了不同均质压力下乳化液黏度、粒径和粒径分布规律,考察了不同均质压力下乳化液特性与鱼油微胶囊包埋率、表面油含量之间的相关性,探讨了喷雾干燥温度对包埋率和鱼油过氧化值(POV)的影响。研究结果表明,随着均质压力的增加,乳化液黏度和平均粒径逐渐减小,而粒径分布离散度总体呈下降趋势,在40MPa时最小,说明此时粒径分布均一性最佳;喷雾干燥温度增加时,鱼油包埋率先增后减,POV值先减后增,在进/出口温度为140℃/70℃时有最高的包埋率和最低的POV值。通过分析确定最佳工艺参数如下,均质压力为40MPa,喷雾干燥进口温度为140℃,出口温度为70℃。在上述最适工艺条件下,鱼油微胶囊平均粒径为5.97μm,表面油含量为2.03%,微胶囊化包埋率为95.6%,在扫描电镜下观察微胶囊表面和内部结构良好,具有良好的包埋效果。

Fish oil was microencapsulated in the wall material of n-octenylsuccinate-derivatized starch （Hi-Cap 100） and glucose syrup. Effects of homogenization pressure on emulsion viscosity, particle size and particle size distribution were studied. The correlation between emulsion characteristic with the microencapsulation efficiency and the surface oil content was shown under different homogenization pressure, the influence of spray drying inlet/outlet air temperature on the morphology, microencapsulation efficiency and peroxide value （POV） was discussed. The results was shown that the emulsion viscosity and average particle decrease, with the increase of the homogenization pressure, while the particle size distribution showing a downward trend in general, and reached the maximum values in 40 MPa, then increased slightly in high pressure. The microencapsulation efficiency of fish oil increased firstlyand then decreased with the increase of spray drying temperature, while the change of POV is opposite. The highest microencapsulation efficiency and the lowest POV were reached at inlet/outlet air temperature 140℃/70 ℃. The optimal process parameters were as follows： homogenization pressure 40 MPa, spray drying inlet air temperature 140 ℃, outlet air temperature 70 ℃. In the above process conditions, the particle had 5.97μm of average size, 2.03% of the surface oil content and 95.6% of the microencapsulation efficiency. The scanning electron microscopy analysis also showed that microencapsulated fish oil had better surface and inside structures.