Abstract: Pine nut oil microcapsules were successfully prepared using gelatin and arabic gum as wall materials by complex coacervation method. The influences of the ratio of gelatin to arabic gum (V/V), the mass ratio of core to wall material, the mass fraction of wall materials, and agglomeration time on microencapsulation efficiency were determined. These processing parameters were optimized using orthogonal array design. Meanwhile, the physicochemical properties of the microcapsules were evaluated and the effect of temperature on their oxidative stability was also analyzed. The highest microencapsulation efficiency of 87.23% was achieved under the optimized conditions: gelatin/arabic gum ratio 2:1, core/wall ratio 2:3, mass fraction of wall materials 2%, and agglomeration time 50 min. The moisture content and solubility of pine nut oil microcapsules was 5.1% and 98.09%, respectively. The interaction between gelatin and arabic gum was analyzed by Fourier transform infrared (FT-IR) spectroscopy, and field emission scanning electron microscopy (FESEM). DSC analysis indicated that complete structure of microcapsules could exist stably at room temperature. The oxidative stability of encapsulated pine nut oil revealed that microencapsulation could enhance the storage stability, prolong the storage period of pine nut oil.

Key words: complex coacervation method, pine nut oil, microcapsules, oxidative stability