Development of food-grade xylanase encapsulation using electrospray dextran microparticles

With the rapid development of pre-mixed flour or pre-baked products, there is a huge market demand for food grade encapsulation of baking enzymes. In our work, a novel method for the food-grade electrospray encapsulation of enzymes was developed using dextran as a polymer matrix. The behavior of dextran in aqueous solution and its effects on electrospray were investigated, and their relationship function was determined. The electrospray properties of dextran were primarily determined by the critical concentration range required for particle formation as well as solution parameters. Subsequently, the encapsulation, characterization, and performance evaluation with respect to the Hmxyn xylanase, an enzyme from Halolactibacillus miurensis were studied. When Hmxyn xylanase was encapsulated with dextran using electrospray, both the dextran-based carrier and the electrospray method did not affect the activity of Hmxyn xylanase, with the encapsulation efficiency and activity recovery rate exceeding 90%. Fourier transform infrared spectra indicated that hydrogen bonding between dextran and xylanase was enhanced, favoring the formation of electrospray particles. In addition, the encapsulated xylanase was uniformly distributed in the dextran matrix and exhibited better thermal degradability and storage stability compared to the free enzymes. Herein, Hmxyn xylanase enzyme encapsulation at room temperature without an organic solvent involved provides a novel, facile, and safe-grade electrospray encapsulation technique that could be extended to more versatile food enzymes or biological additives.