Method of making structured protein compositions
An extrusion process is disclosed for turning vegetable protein compositions such as soy protein into a fibrous, meat-like structure. The process involves the application of relatively high moisture contents. An open structure is produced that can be infused with water so as to influence the product's tenderness. The products of the invention can be provide with a fibrosity and tenderness at will. The invention offers the possibility to include relatively high amounts of fat in the product.
1. A process for the preparation of a structured vegetable protein extrudate having a fibrous meat-like structure, comprising the steps of:
(a) providing an aqueous protein composition comprising vegetable protein, wherein a protein content based on dry matter is at least 15% by weight and below 85% by weight, and wherein water content of the aqueous protein composition is at least 50% by weight;
(b) subjecting the aqueous protein composition to one or more kneading steps so as to form a dough;
(c) subjecting the dough to heating to above a denaturation temperature of the protein, wherein the denaturation temperature is at least 130 ° C.;
(d) subjecting the heated dough to shear forces and pressure in an extruder, so as to form a fibrous protein composition;
(e) subjecting the fibrous protein composition to a limited cooling to at least the boiling temperature of water in a longitudinal die section provided prior to the exit through the extruder die so as to exit the extruder at a temperature, of the fibrous protein composition, of at least the boiling temperature of water in a first outside environment, thereby forming a cooled fibrous protein composition having enhanced porosity and/or randomization of fiber orientation relative to a fibrous protein composition cooled to below the boiling temperature of water;
(f) allowing the cooled fibrous protein composition to exit the extruder through the extruder die and enter the first outside environment.
2. The process according to claim 1 , wherein the protein content based on dry matter is in a range of from 15% by weight to 85% by weight, and preferably in a range of from 50% by weight to 80% by weight.
3. The process according to claim 1 , wherein the aqueous composition is provided to the extruder, and the kneading and denaturing steps (b) and (c) are conducted in the extruder.
4. The process according to claim 1 , wherein the extruder has an L/D ratio of length : diameter greater than 20.
5. The process according to claim 4 , wherein the L/D ratio is 40 to 50.
6. The process according to claim 1 , wherein the vegetable protein is soy bean protein.
7. The process for the preparation of a structured vegetable protein composition comprising preparing a structured vegetable protein extrudate in accordance with claim 1 or claim 6 , and allowing the extrudate to be infused with an aqueous liquid.
8. The process according to claim 7 , wherein the structured vegetable protein extrudate has been subjected to freezing prior to infusion.
9. The process according to claim 7 , wherein the aqueous liquid is heated.
10. The process according to claim 7 , wherein the aqueous liquid is water comprising flavors.
11. The process of claim 1 , for production of a range of a meat-like fibrous structured vegetable protein composition, wherein the choice of one or more temperature values in step (c) is used as a tool to determine the desired fibrosity.
12. The process of claim 11 , wherein the water content introduced by infusion according to claim 7 is used to determine the desired tenderness.
13. The process according to claim 4 , wherein the extruder has an L/D ratio of length : diameter greater than 30.
14. The process according to claim 9 , wherein the aqueous liquid is heated to a temperature of 70 ° C. to 98 ° C.
15. The process according to claim 10 , wherein the aqueous liquid is a broth.
16. The process according to claim 2 , wherein the protein content based on dry matter is in a range of from 50% by weight to 80% by weight.