Effects of particle sizes on structural and physicochemical properties of pomelo peel powders

摘要

The structural and physicochemical properties of pomelo peel powders with differentparticle sizes were investigated. The MasterSizer and scanning electron microscopyobservations indicated that three pomelo peel powders with different particlesizes were successfully prepared via jet milling, of which the average diameters (d_((90)))were 53.43 ± 0.49, 27.73 ± 0.13, and 20.15 ± 0.17 μm. Fourier-transforminfraredspectroscopy, X-raydiffraction, and low field nuclear magnetic resonance analysisindicated that the functional groups of pomelo peel powders were not affected byparticle size; while the crystal region, proportion of immobile water (A_(22)) and freewater (A_(23)) decreased with reduced particle size. The decrease in the proportion ofimmobile water and free water resulted in reduced solubility and water-holdingcapacityof pomelo peel powders with the smallest particle size. Our findings suggestthat the desirable properties of pomelo peel powders can be designed by appropriateparticle size.