Fibril from food-grade materials is an important fundamental area of current researches in food systems. At first, in this study emulsifying properties of non-heated soy protein isolate -native SPI- and SPI fibril were compared. Then, the optimal concentration of SPI fibril was selected for microencapsulation of limonene by VIKOR method. The results indicated that SPI fibril interfacial tension oil/water -O/W- -5.88 mN/m- emulsion droplet size decreased and encapsulation efficiency -65.47%- was raised. The emulsifying activity index -EAI- -38.02 m2/g- and emulsion stability index -ESI- -23.5 min- of the emulsion prepared with 1% -w/v- SPI fibril were significantly higher than -31.21 m2/g and 15 min, respectively- of the native SPI. SEM images showed that the microcapsules obtained from the SPI fibril were smaller, more homogenous and smoother in their surfaces. The performance of the SPI fibril was better in forming and stabilizing the emulsion than the native SPI at the same concentration, based on the FTIR spectrum. VIKOR method was applied to obtain the best concentration of SPI fibril by ranking the scenarios, which its concentration of 0.5% -w/v- SPI fibril was chosen as the best. This study illustrated that SPI fibril can improve the emulsifying properties and microencapsulation efficiency of flavor and active cores.

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