Peanut preparation: shelling, grading, roasting, and aflatoxin control
Pretreatment hard data: drum sheller residue <2%, kernel grading 1000-kernel weight 400-700 g, moisture conditioning to 5-8%, roast 160-180°C × 20-30 min in drum or wok (50-200 kg/batch), aflatoxin B1 <20 μg/kg via UV/HPLC sorting.
Shelling specification
Drum sheller (capacity 300-1000 kg/h pods) → grading screen → wind separator. Target shell residue in kernel <2%, broken kernels <5%, foreign matter <0.1%.
Roasting specification
Drum roaster 160-180°C × 20-30 min, batch 50-200 kg, color L* 50-60. Or wok roaster (traditional, 50-100 kg/batch). Cold route: skip roasting, ambient ≤60°C feed.
Moisture and aflatoxin
Moisture target 5-8% (>10% blocks press cake formation; <4% over-dried cake cracks). Aflatoxin B1 <20 μg/kg by UV sorting at intake + HPLC lab test per inbound lot.
Why prep dominates
Why shelling and roasting decide the press outcome before tonnage
Peanut press performance is set upstream. Kernel oil 44-56% only converts to yield 40-48% when shell residue <2%, moisture 5-8%, roast 160-180°C × 20-30 min, and damaged/moldy kernels rejected. Without these, even a 500-ton press underperforms.
Peanut shelling, cleaning, and feed condition
Use this clip to decide whether shelling, cleaning, and grading belong in the current phase.
Separate pods, shelled kernels, and graded kernels
Different feed starting points change prep, roasting, pressing, and filtration scope.
- Shell residue <2% (otherwise barrel partitions clog, pressure drops, residual cake oil rises >10%).
- Moisture 5-8% (>10% prevents cake formation; <4% gives brittle cake and oil bypass channels).
- Roast color L* 50-60 (hot route) — too light = under-developed cell rupture, too dark = scorched flavor and PAH risk.
Module specifications
Pretreatment modules with capacity ranges
Drum sheller + grading
Capacity 300-1000 kg/h pods (shell 30-40%). Output: kernels (60-70% by weight) + shells. Add vibrating grader for size uniformity (1000-kernel 400-700 g).
Drum roaster 160-180°C
Stainless steel drum, gas or electric, 50-200 kg/batch, 20-30 min residence time. Continuous belt roasters also available for >500 kg/h flow. Log temperature curve per batch.
Flat-bottomed electric wok
Traditional 小榨花生油 setup, 50-100 kg/batch, manual stirring or motorized paddle. Lower throughput but stronger aroma development. Common in artisan peanut oil mills.
Inquiry inputs
Preparation data that closes the quote loop
- Pods or kernels? If pods, shell content (30-40%) and shelling capacity needed (kg/h).
- Kernel grade: 1000-kernel weight, broken-kernel %, moisture %, foreign matter %.
- Aflatoxin status: lab certificate per lot, UV sorter present? Storage RH <70%?
- Roasting: drum (continuous) or wok (batch)? Target temperature (160-180°C) and time (20-30 min)?
- Cake target: feed grade, food-grade peanut flour (defatting + grinding), or local resale?
Questions to confirm next
What shelling residue is acceptable for hydraulic pressing?
Drum roaster or wok roaster for hot peanut?
Read this next
These next pages move the peanut discussion forward
Ready to size a line for your oilseed?
Share peanut feed form, shelling status, target output, roasting method, filtration requirement, and cake destination so the scope can be narrowed to the right machine class and project boundary faster.