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Onion and garlic dehydration
Kibbled, chopped, minced, granules and powder; fried onion; garlic flakes and powder
Onion and garlic dehydration line by GEM Foodtech, Kolkata, India — capacity 1 to 20 tonnes of raw onion per hour, final yield 12.5% of raw intake, delivered as a turnkey plant with installation and commissioning worldwide.
The commercial reality
Onion is the hardest common vegetable to dry well. Eighty-seven percent of it is water, the pungency you are selling is volatile, and the sugar caramelises if the first zone runs hot. Multi-stage drying with a falling temperature profile is the whole answer, and it is why cheap dryers make brown powder.
Process flow diagram
Generated for the standard configuration. Yours is redrawn to your product mix, capacity and site.
Process chart
Every stage with the equipment that performs it, the operating parameter and the control point that decides quality.
| # | Stage | Equipment | Parameter | Control point |
|---|---|---|---|---|
| 01 | Topping and tailing | Inspection and sorting conveyor | Manual or automatic, root and neck removed | Uniform bulbs to the peeler |
| 02 | Peeling | Peeler, abrasive or steam | Air peeling or manual finishing | Skin content below 0.5% |
| 03 | Washing | Fruit and vegetable washer | Cold water rinse, chlorinated | Surface load and loose skin removed |
| 04 | Slicing | Slicer, dicer and shredder | 3–6 mm slices or kibble cut | Thickness uniform — it sets drying time |
| 05 | Drying | Belt dryer and dehydration system | Multi-stage belt dryer, 75 → 60 → 50 °C, to 5% moisture | Colour and pungency retained |
| 06 | Cooling | Fluid bed dryer and cooler | Fluid bed cooler to ambient | No condensation in the bag |
| 07 | Milling and grading | Grinder and pulveriser | Mill and sifter to kibble, granule or powder | Mesh grade separation |
| 08 | Packing | Filling, sealing and packing line | Metal detection, moisture-barrier packing | Final moisture at 4–6% |
Mass balance
Basis of 1,000 kg of raw material. Change the tonnage below and the whole table rescales.
| Stage | Output, kg/h | Yield | Loss, kg/h | Where the loss goes |
|---|---|---|---|---|
| Raw onion received | 1,000 | 100% | 0 | — |
| After topping, tailing and peeling | 880 | 88% | 120 | Skin and roots to compost or biogas |
| After slicing | 870 | 87% | 10 | Trim losses |
| Dried at 5% moisture | 130 | 13% | 740 | Water evaporated |
| Graded product | 125 | 12.5% | 5 | Fines and oversize, sold as powder grade |
By-products: Skins, roots and trim to biogas or compost; fines recovered as powder grade rather than waste.
Equipment schedule
Core machines for this line. Conveying, tanks, CIP and utilities are added to suit the layout.
| Equipment | Capacity range | Function |
|---|---|---|
| Inspection and sorting conveyor | Preparation | Manual or optical removal of unripe, damaged and foreign material. |
| Peeler, abrasive or steam | Preparation | Abrasive carborundum drum or batch steam peeler with flash vessel. |
| Fruit and vegetable washer | Preparation | Removes field soil, latex and surface load with recirculated, filtered water. |
| Slicer, dicer and shredder | Preparation | Uniform slices, dices, strips or kibble — cut geometry sets drying time. |
| Belt dryer and dehydration system | Drying | Multi-zone drying with controlled curve — the GEM core competence. |
| Fluid bed dryer and cooler | Drying | Finishing and cooling of granular product to bagging temperature. |
| Grinder and pulveriser | Size reduction | Hammer, pin or cryogenic milling to a controlled mesh. |
| Filling, sealing and packing line | Packing | Weighing, filling, sealing, metal detection and case packing. |
Questions we get on this line
What is the true yield?
About 12 to 13 kg of dried product per 100 kg of raw onion. Every feasibility that assumes more than that is wrong, and it is the most common costing error in this business.
Can the same line dry garlic?
Yes. Garlic has lower moisture and a shorter drying time, so the same machine gives higher throughput on garlic than on onion.
What capacity range does the onion and garlic line cover?
Standard GEM Foodtech builds cover 1 to 20 tonnes of raw onion per hour. Larger duties are engineered to order — the right size is set by the raw material supply through the season, not the nameplate figure.
Is this supplied as a complete turnkey plant?
Yes. The Onion and garlic dehydration line is delivered end to end — feasibility, pilot trial on your own material, engineering, manufacture in Kolkata, installation, commissioning and operator training — or as individual machines to fit an existing plant.
Want this line costed for your tonnage?
Send the raw material specification and the capacity you are targeting. You get a flow diagram, an equipment schedule and a budget number.