When sourcing natural vegetable powder, the primary focus should be on the processing technology and raw material traceability. High-quality powders are typically produced via Freeze-Drying (FD) or Low-Temperature Spray Drying to preserve heat-sensitive vitamins, enzymes, and the natural color. You must request a Certificate of Analysis (COA) for every batch, specifically checking for moisture content (should be <5%), mesh size (fineness), and the absence of carriers like maltodextrin unless specified. Ensure the supplier follows GMP (Good Manufacturing Practices) and holds ISO 22000 or HACCP certifications to guarantee food safety.