Effect of Superfine Grinding on Physicochemical Properties and Microstructure of Chimonobambusa quadrangularis Shoot Powder

To explore the effect on the physicochemical properties and microstructure of Chimonobambusa quadrangularis shoot powder (CQSP), superfine grinding of dried Chimonobambusa quadrangularis was conducted for different grinding time (10, 20 and 30 min). Results showed that when superfine grinding for 30 min, compared with the coarse powder control group, the protein and total sugar content of CQSP increased by 7.48% and 44.76% respectively, the water holding capacity, oil holding capacity and swelling capacity decreased by 29.34%, 26.43% and 22.87% respectively, and the average particle size of the powder reached the minimum of 17.15 μm. After superfine grinding, the slip angle and repose angle of CQSP increased by 38.24% and 20.63% respectively, the brightness value increased by 13.93%, the red green value and yellow blue value decreased by 24.21% and 16.51%, respectively. The fluidity of the powder became poor, but the powder was more delicate, the color was more uniform and bright. Superfine grinding would not change the functional groups of CQSP, but destroy the cellulose in powder, part of the long chain would become short chain, and reduce the thermal stability. Scanning electron microscopy (SEM) showed that the surface structure of the CQSP was destroyed via superfine grinding, making the samples tiny, uniform and fragmented. In conclusion, the superfine grinding technology could effectively improve the sensory properties, functions and processing characteristics of CQSP, and would provide a theoretical basis for improving the utilization rate and expanding the application.