Superfine grinding of Dendrobium officinale: the finer the better?

In this study, Dendrobium officinale powders with different particle size were prepared, and the functional components solubility, phenolic compounds contents and antioxidant activities were determined and compared. Results showed that powders with smaller particle size usually showed better physicochemical properties compared with coarse ones; however, finer particles were not necessarily better. The nutritional ingredients solubility, antioxidant components contents and antioxidant activities increased with an initial decrease in particle size and then plateaued, indicating that rational processing can meet its objectives. The obtained results indicated that particle size of ~30 μm was suitable for D. officinale powder processing considering the nutritional ingredients solubilities and the antioxidants contents; while from the point of view of antioxidant activities, ~20 μm could meet the requirements. An understanding of the influences of micronization on physicochemical properties of D. officinale was expected to provide new insights in guiding the development of micronized food powders in practice.