Full Process Flow (Low-Moisture Twin-Screw Extrusion, Industrial Standard)
Raw material preparation → Dry mixing → Pre-conditioning & hydration → Twin-screw extrusion cooking & texturization → Die forming & rotary cutting → Hot-air drying → Cooling → Sieving → Flavoring (optional) → Packagingloyalfoodm…
1. Raw Material Preparation
Main raw material: Low-temperature defatted soy flour (protein 50–55%, fat <1%). Optional additives: Vital wheat gluten, corn starch, edible salt, pH regulators, food color, anti-oxidants.
- Clean soy flakes → Crushing → Milling → Sieve into 70–90 mesh fine powder; remove coarse particles to guarantee uniform extrusionShandong L….
2. Dry Mixing
Blend soy flour and auxiliary powders evenly in a double-shaft mixer for 15–30 minutes to achieve consistent composition batch by batchShandong L….
3. Pre-Conditioning & Hydration
- Add clean water or low-pressure steam to adjust the material moisture to 20–25%.
- Preheat the material to 60–80 ℃ to start protein softening; avoid local overheating before extrusionFood and A….
4. Core Step: Twin-Screw Extrusion Cooking & Texturization
Equipment: Co-rotating twin-screw extruder with multi-temperature zones.
Technical parameters
- Barrel temperature gradient: 50℃ → 90℃ → 130℃ → 160℃ → 180℃ (feeding zone to die zone)
- Working pressure: 30–50 bar
- Screw speed: 300–500 rpm
Physical changes inside the barrel
High temperature + high shear force denatures globular soy protein. Protein molecules unfold and align directionally, forming continuous fibrous meat-like tissue structure. When the material is extruded out from the die nozzle, pressure releases instantly, and the product expands to form porous soya meat chunks/grains.
5. Forming & Cutting
Different die molds produce chunks, granules, strips or minced meat shapes. A high-speed rotary cutter cuts the hot extrudate into fixed sizes right after exiting the dieloyalfoodm….
6. Drying
Transfer wet semi-products into a multi-layer belt dryer.
- Drying temperature: 80–120 ℃
- Target moisture: reduce from 22–26% down to 8–10%Purpose: lock the fibrous texture, prevent mildew and extend shelf lifeloyalfoodm….
7. Cooling & Sieving
- Cool dried soya meat to room temperature in a cooling conveyor to avoid condensation inside bags.
- Sieve finished products to remove fine powder and broken scrapsDayi.
8. Optional: Flavor Coating
For seasoned soya meat: spray vegetable oil, meat extract, spices and seasoning in a continuous seasoning drum.
9. Automatic Weighing & Packaging
Seal with moisture-proof plastic bags to finish the whole production lineDayi.