Process Optimization of Lycium ruthenicum Murr. Powder Preparation by Airflow Ultrafine Pulverization at Low Temperature and Characterization of its Antioxidant Activity

The processing of ultrafine pulverization Lycium ruthenicum Murr. by airflow is studied to determine the best parameters. Based on the single factor experiment, orthogonal experimental design is utilized to optimization of process parameters. The results show that the water content is 0.5%, air supply pressure is 0.70 Mpa, graded speed is 55 Hz, freezing time in the liquid nitrogen is 2 h. Under the condition of repeated trials, the average grading of L. ruthenicum fruit submicron powder is 19.8167 +/- 0.53 mu m. The contents of the total polysaccharides, anthocyanin and antioxidant activity in the water extract of submicron powders are obviously higher than the normal powder's, which can efficiently increase the dissolution rate of active ingredients in L. ruthenicum Murr.