Abstract: Sulforaphane (SF) was microencapsulated with different wall materials using electrospraying. By characterizing the surface morphology, intermolecular interactions, thermal behavior, in vitro release behavior, and storage stability at high temperatures of microcapsules, the microencapsulation efficiency of SF with food-grade polymers was studied in order to select the optimal wall material for encapsulating SF. The results showed that the average particle size of the prepared microcapsules was in the range of 427.80-1 857.04 nm, with spherical shape and smooth surface. Compared to chitosan, zein and gelatin were more effective in SF delivery with encapsulation efficiencies of (95.83 ± 2.37)% and (95.11 ± 2.82)%, respectively. Infrared spectroscopy confirmed successful microencapsulation of SF. Thermogravimetric analysis showed that the microcapsules had high thermal stability as substantial degradation occurred only at temperatures above 300 ℃. The final release rate of SF from the microcapsules in simulated gastrointestinal fluid and food matrices was between 80% and 90%, indicating good gastrointestinal dissolution and release performance. Besides, the heat resistance of SF was significantly improved after microencapsulation. This study will be useful for the development of SF delivery vectors in order to enhance its industrial applications.

Key words: sulforaphane; microencapsulation; electrospraying; characterization; in vitro release; stability