Real-World Case Study: Optimizing Steam Cooking Parameters to Reduce Oil Residue in Pressed Cake

In the competitive global edible oil market, even a 1–2% improvement in oil extraction efficiency can translate into significant profit gains for mid-sized oil mills. A recent case study from a client in Ukraine highlights how precise adjustments to steam cooking parameters—part of the pre-treatment process—reduced residual oil in pressed cake from an average of 7.5% to just 4.2%, while also improving oil clarity and reducing machine downtime.

Why Pre-Treatment Matters More Than You Think

Many small-to-mid-scale oil processors overlook the critical role of pre-treatment—especially steam cooking—in determining final oil yield and quality. For sunflower seeds and sesame, both highly valued in Europe and Middle East markets, improper moisture control during steaming leads to either under-cooked kernels (high residue) or overcooked material (lower oil quality).

Our client used a medium-sized screw press (capacity: 5–10 tons/day). Initially, they followed generic guidelines: 10 minutes at 95°C with 12% moisture content. But after analyzing their output data over three months, we found that inconsistent grain size and uneven heating caused up to 20% variation in cake oil content across batches.

Data-Driven Adjustments That Worked

Based on lab testing and field observations, here’s what changed:

• Sunflower seeds: Reduced steaming time from 10 to 7 minutes at 92°C (moisture adjusted from 12% to 10%) — resulting in oil residue dropping from 7.8% to 4.5%.
• Sesame seeds: Increased steaming duration slightly to 8.5 minutes at 96°C (moisture kept at 11%) — improved oil recovery by 3.2%, with residue falling from 7.2% to 3.9%.

These changes were not arbitrary—they came from systematic sampling, temperature mapping inside the cooker, and real-time moisture monitoring using infrared sensors. The key takeaway? One-size-fits-all recipes don’t work when dealing with different oilseed types and local climate variations.

Solving Common Issues: Blockages & High Oil Residue

Two recurring problems plagued this mill before optimization:

1. Material blockage in the feeding system: Caused by inconsistent particle size (< 2mm vs > 5mm). Solution: Added a secondary crushing stage with adjustable gap settings (set to 3.5mm).
2. High oil residue (>6%): Traced back to poor steam penetration due to overloaded cookers. Implemented batch-level steam pressure regulation (from 0.6 MPa to 0.45 MPa), which reduced energy use and increased uniformity.

Post-adjustment, the plant saw a 35% drop in maintenance calls related to clogged feeders and a consistent 4.0–4.5% oil residue rate across all production runs—a clear win for both productivity and profitability.

While no single solution fits all, these insights show how targeted technical adjustments—not expensive new equipment—can drive measurable improvements in oil yield, product consistency, and operational reliability.