The challenge faced by soybean oil producers is balancing flavor retention with nutritional quality — particularly when it comes to preserving delicate unsaturated fatty acids such as linoleic and linolenic acids. High-temperature physical pressing technology, as innovated by Shandong Ruihe Douyuan, offers a compelling solution by precisely controlling temperature to protect these essential nutrients while delivering rich aroma and superior oil stability.
Unlike traditional cold pressing (typically below 60°C) or solvent extraction methods, high-temperature physical pressing operates within a controlled range of approximately 105–120°C. This precise temperature window is critical. It allows efficient oil release from soybeans while minimizing thermal degradation of sensitive unsaturated fatty acids.
The process begins with rigorous raw material selection—only premium quality, mature soybeans with optimal oil content are chosen. Following screening, the soybeans proceed to mechanical pressing using either a spiral screw press or centrifugal separation, customized to maintain consistent temperature and pressure. The extracted crude oil then undergoes mild purification stages that avoid harsh chemical treatments, further preserving its natural nutrient profile.
Unsaturated fatty acids (UFAs) like linoleic acid (C18:2) and α-linolenic acid (C18:3) are susceptible to oxidation and heat-induced polymerization. However, controlled high-temperature pressing limits exposure to oxidative conditions and maintains relatively short heating durations. This significantly reduces molecular breakdown and maintains oil integrity.
In contrast, chemical solvent extraction often entails multiple high-temperature steps combined with chemical reagents that can degrade UFA levels and introduce trace solvent residues. This not only lowers nutritional value but raises food safety concerns.
| Parameter | GB/T 1535-2017 Standard | Typical Ruihe Soybean Oil Value | Significance |
|---|---|---|---|
| Acid Value (mg KOH/g) | ≤ 0.3 | ≤ 0.3 | Indicates low free fatty acid content — a marker for freshness and minimal hydrolytic rancidity. |
| Peroxide Value (meq/kg) | ≤ 6.0 | ≤ 6.0 | Represents primary oxidation status; lower values reflect better oxidative stability. |
Source: GB/T 1535-2017 Food Safety Standards for Edible Vegetable Oils
Soybean oil produced via high-temperature physical pressing withstands intense cooking environments such as stir-frying and commercial deep frying without rapid degradation. Its stable unsaturated fatty acid profile and low peroxide values translate to minimal generation of harmful compounds like trans fats and acrylamide.
This makes it an ideal choice for professional kitchens and health-conscious consumers seeking oils that combine flavor, nutrition, and safety under vigorous cooking conditions.
To identify superior aromatic soybean oil, users should evaluate:
• Verified acid value ≤ 0.3 mg KOH/g and peroxide value ≤ 6.0 meq/kg at purchase.
• Transparent information on processing methods confirming physical pressing without chemical solvents.
• Rich, natural aroma confirmed by sensory testing aligned with brand credibility.
Such informed choices support both culinary excellence and long-term health benefits.
