For small to medium-sized oil mills, achieving consistent oil quality isn’t just about raw material selection—it starts with precise temperature control during the pressing process. A well-engineered screw press system doesn’t just extract oil efficiently; it ensures purity, minimizes oxidation, and boosts yield by up to 8–12% when temperature is optimized per feedstock.
The helical design of the screw shaft directly impacts how evenly pressure builds across the oilseed bed. Inefficient designs cause uneven compression—leading to under-pressed kernels at the front and over-heated zones at the rear. This inconsistency not only reduces output but also increases rancidity risk due to localized hot spots. According to a 2023 study from the International Journal of Food Engineering, mills using variable pitch screws saw a 7% improvement in oil recovery compared to fixed-pitch models.
Each oilseed has an ideal pressing temperature range:
| Oilseed Type | Optimal Pressing Temp (°C) | Impact on Oil Quality |
|---|---|---|
| Peanuts | 60–70°C | Reduces free fatty acids, improves clarity |
| Soybeans | 65–75°C | Minimizes protein denaturation, enhances shelf life |
| Canola Seeds | 55–65°C | Prevents thermal degradation of omega-3s |
“We used to press soybeans at 80°C because we thought higher heat meant more oil,” says Ahmed Hassan, operations manager at Al-Masri Oil Mill in Egypt. “But after switching to a precision-controlled system, our oil had less sediment, better taste, and passed EU lab tests without any additives.”
Preheating oilseeds before pressing improves flowability and reduces mechanical resistance inside the press. This leads to smoother operation and lower motor load—saving up to 15% energy consumption annually. For example, a 3-ton/day peanut mill in Nigeria reported a drop from 18 kW/h to 15.3 kW/h per ton after installing a preheater module with automatic temperature feedback.
Many small mills overlook two critical factors:
When evaluating a new screw press, ask vendors these three questions:
These aren't just technical details—they're strategic decisions that impact long-term profitability and brand reputation.
Discover how our SmartTemp™ Series of medium-scale screw presses help small-to-mid oil mills achieve consistent oil quality, reduce waste, and cut energy costs—all while meeting international standards.
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