Drying and Grinding Characteristics of Dandelion (Taraxacum officinale Weber ex F.H. Wigg) Flowers

Dandelion flowers are a valuable source of bioactive compounds with well-documented health-promoting properties. However, their high water content and delicate tissue structure make them highly perishable; therefore, appropriate preservation methods are essential to maintain their biological activity. The aim of this study was to evaluate the effects of convective drying and freeze drying, as well as drying temperature, on the drying kinetics and grinding behavior of dandelion (Taraxacum officinale Weber ex F.H. Wigg.) flowers and on the color and antioxidant properties of the resulting dried material. Convective hot-air drying was several times faster than freeze drying, and drying temperature significantly affected both the duration of the process and the properties of the dried flowers. Moreover, freeze-dried samples exhibited greater grindability and higher antioxidant activity than convectively dried flowers. In addition, powder obtained from freeze-dried dandelion flowers was lighter in color and exhibited lower redness and higher yellowness compared with samples obtained by hot-air drying. Both color coordinates and particle size after grinding were correlated with the antioxidant activity of the dried material.