Why Does Sesame Oil Develop Unpleasant Odors? A Technical Guide for Producers

Sesame oil is prized globally for its rich aroma and nutritional value—but when it develops off-odors, it can damage brand reputation, reduce shelf life, and lead to customer complaints. According to a 2023 report by the International Oleochemical Society, over 32% of small-scale sesame oil producers in Southeast Asia reported quality issues linked to odor variation within six months of production.

Key Factors Behind Sesame Oil Odor Issues

The root causes often lie in four critical stages: raw material handling, extraction method, temperature control, and post-processing filtration. For instance, if sesame seeds are not dried below 10% moisture content before pressing, microbial activity during storage can produce rancid compounds—especially problematic in tropical climates where humidity exceeds 70%.

Cold-pressed oils typically retain more natural flavor but require precise temperature management (ideally between 40–55°C). In contrast, solvent-extracted methods may introduce residual chemicals unless thoroughly refined—a common issue in facilities using outdated equipment.

How to Diagnose and Solve Common Problems

A systematic approach includes:

• Testing seed cleanliness via FTIR spectroscopy to detect mold or foreign matter (ideal threshold: < 0.5% contamination)
• Monitoring press temperature with real-time sensors—not just thermometers—to avoid overheating that breaks down volatile esters
• Implementing multi-stage filtration (e.g., ceramic filters + activated carbon) to remove trace aldehydes and ketones responsible for stale smells

In one case from Nigeria’s AgroFood Industries Ltd., switching from manual decanting to automated vacuum filtration reduced odor complaints by 68% in three months—an outcome directly tied to improved removal of free fatty acids and phospholipids.

Small vs. Industrial-Scale Production Challenges

While large factories use continuous deodorizers operating at 180–200°C under vacuum, smaller units often lack this capability. However, even modest upgrades—like installing a plate-and-frame filter press or integrating a low-cost thermal desorption unit—can significantly improve consistency and safety.

Producers who invest in these technologies see faster turnover, fewer returns, and stronger buyer trust—especially important when exporting to EU markets where food safety compliance is non-negotiable.