When sourcing dried vegetable powder, the primary focus should be on nutrient retention and purity. High-quality powders are typically produced via Freeze-Drying (FD) or Low-Temperature Spray Drying, which preserve the color, flavor, and vitamins better than traditional hot-air drying. You must verify that the product is 100% pure with no added maltodextrin, artificial colors, or preservatives unless specifically requested. Request a Certificate of Analysis (COA) for every batch to check for moisture content (should be <5%) and mesh size (typically 60-120 mesh) to ensure solubility and texture consistency.