| Parameter | Specification |
| Appearance | Fine, free-flowing powder |
| Color | Off-white to light brown (deeper brown if roasted) |
| Odor | Strong, characteristic onion aroma (milder and sweet if roasted) |
| Taste | Pungent, slightly sweet, roasted flavor (depending on process) |
| Texture | Dry, smooth, and powdery |
| Moisture Content | ≤ 6% |
| Bulk Density | 400 – 650 kg/m³ |
| Particle Size | 100 – 500 microns (depending on grind and processing) |
| pH Level | 5.5 – 6.5 |
| Volatile Oil Content | 0.2% – 0.5% (roasted may be slightly lower) |
| Ash Content | ≤ 6% total ash; ≤ 1% acid-insoluble ash |
| Shelf Life | 12 – 24 months (cool, dry, airtight storage) |
| Flowability | Good; anti-caking agents may be added for industrial use |