Comment valoriser dans l’alimentation animale, les graines de soja produites en France ? Comparaison de deux procédés de transformation : l’aplatissage-cuisson-pression et l’extrusion-pression

Abstract

Cooking-pressing or extrusion-pressing processes applied to soybeans produce partially deoiled cake used for animal feeding. These two processes were studied and compared with a view to implementation in an industrial unit. The various factors of hydrothermal treatment for conditioning the beans were studied at different scales (batch from 2 kg to 100 kg, and continuous flow at 100 kg/h) and the results showed the need for moist cooking to effectively deactivate the antitrypsin factors (FAT) while maintaining protein solubility. The extrusion-pressing was more effective for deoiling cakes than cookingpressing (5.4 vs. 6.7%) but less robust for deactivation of FAT (6.5 vs. 3.8 TIU/mg). The techno-economical study was carried out to simulate the crushing costs and net margins of both processes in a plant capacity of 20 000 t / year. It showed that the costs of both methods were similar (about 33 €/t). Gross margins were evaluated between 18 and 84 € / t in three valuation assumptions based on market price of oil, the mode value of the meal and the residual oil, the level of premiums GMO traceability and transport. The cooking-pressing process can also be applied to sunflower and rapeseed and versatility is an advantage to ensure continuous operation of the crushing unit in case of supply difficulties in soybean.

Keywords

• soybean
• extrusion
• pressing
• cooking
• valorization
• soymeal