Post
by Chuckwagon » Tue Aug 20, 2013 23:46
Krakowska, your "soy flour" contains about half the protein that soy protein concentrate or soy protein isolates have. Nevertheless, it is a viable products and used in many food applications.
Before the Roaring Twenties, soy was considered to be an industrial product used in paint, fire extinguishers, and other applications. Then we remembered that the Chinese had fermented this stuff for quite some time and enjoyed soy sauce, soy milk, tofu, fermented bean paste, natto, and tempeh. SPC and SPI were made to increase the protein content and bind fat and water in meat products. Back then, if more than 5% was used, it imparted a "beany" flavor to the meat. Today, this is not a problem with SPC (soy protein concentrate) and SPI (soy protein isolate), used by athletes to build muscle. Goodness pard, even the FDA has approved soy as an "official" cholesterol-lowering food benefitting the heart and other organs. In 1995, the FDA said, "Twenty-five grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease".
Soy is a "complete" source of protein, meaning it contains extensive amounts of "essential" amino acids. These are the amino acids that must be provided TO the human body regularly because we humans simply cannot synthesize them.
Modern soy products include soy flour, textured vegetable protein, soy oil, soy protein concentrate, soy protein isolate, soy yoghurt, soy milk, and whew... soy animal feed for farm animals and even fish!
Krakowska, "soy flour" is made in three "grades". Soy beans are "milled" (much like flour is made) and, depending upon the desired amount of oil extracted from the beans, the result may vary anywhere between a fine powder and coarse grits.
Full-fat soy flour - 35%
Low-fat soy flour - 45%
Defatted soy flour - 47%
Soy proteins serve as a binder and as a fine powder it covers meat and fat particles particularly well. Forming a low grade gel, it entraps and holds moisture. When heated, this gel compound contains liquid within, keeping a burger, sausage, or other meat from shrinking. Soy insures firmness and juiciness. Further processed, TSF (textured soy flour) is made from soy flour extruded into specific shapes, much like macaroni is formed. The final product becomes chewy when it is hydrated.
TSP (textured soy protein) contains about 50% protein. This product is also known as TVP (textured vegetable protein) and it contains very little fat, no cholesterol, and it is rich in fiber.
Soy protein concentrate is about 60% protein and can bind 4 parts water. It will not gel because SPC contains insoluble fiber. However, it will develop a paste and is re-hydrated at a ratio of 1:3.
Soy protein isolate is 80% - 90% protein and does not contain the fiber SPC does. As it is manufactured, the fats and carbohydrates are removed from the product. Therefore it will gel without a trace of flavor. Soy protein isolate binds 5 parts water.
Best Wishes,
Chuckwagon
If it looks like a duck, walks like a duck, and quacks like a duck, it probably needs more time on the grill! 