Manufacture of Soy Protein Feed

Soy feed is characterized by a very high digestibility of the protein, which is why it has become the best known and most widely used protein feed component on the market. There are three main types: toasted soybean (approx. 20% raw fat), toasted soybean cake (approx. 10% raw fat) and soybean meal (approx. 1-2% raw fat) produced in large plants.

Processing of soybeans

The processing of soybeans is now almost exclusively in the industrial hands. Unfortunately, the industrial processing of food and feed often does not focus on good product properties (health-promoting ingredients, taste, …), but on cost-optimized production technology and on the smallest possible fluctuations in the technical properties (today’s quality term).

Industrial edible oil production

This can be easily explained using the example of industrial edible oil production. In order to achieve the maximum oil yield, the oilseed is crushed and the oil with a solvent, e.g. „Washed out“ hexane. Since some of the agents required for this are considered carcinogenic substances or have no other positive health effects, both the meal and the oil must be heated to a very high level so that as much of the solvent as possible is extracted from the food and animal feed can be removed. As a result, protein digestibility is impaired in the case of the meal (the digestibility of protein in oil meal is always worse than in the case of presscake) and in the case of vegetable oils, carcinogenic trans fats are produced from the healthy unsaturated fatty acids. For retailers, this has the positive side effect that, due to the reduced biological value, the growth of microorganisms in the meal and oil is also reduced, thus increasing the shelf life. The oils are often removed by degumming (addition of phosphorous acid) and refining (acid or alkaline saponification) flavors and ingredients that can be used for industrial food production or nutritional supplements. The end result is vegetable oils that consistently have neither a natural color nor a recognizable taste that could fluctuate naturally.

Advantages of decentralized oil mills

When processing soy and other oil seeds in decentralized oil mills, the seeds are handled much more gently – no solvents, only mechanical pressure, no unnecessary heating – and secondly, it is not worth removing valuable substances in the oil in order to use them otherwise to sell. The advantages for the consumer are obvious: better digestibility of the soy feed for livestock and higher quality edible oils for the kitchen. However, the residual oil level of a meal cannot be reached with the press cake. Often, oil pressure only comes close to 10% residual fat, as opposed to 1-2% for shot.

Soy press cake

Experience has shown that soy press cake after toasting with the Ecotoast has approx. 10% residual fat and a raw protein content of around 45% (in the dry matter). In addition, the protein digestibility of the soy feed is much better due to the minimized temperature influence and the taste is also much more appealing. As a rule, the cake is used as a high-quality protein food, but there is also no reason not to use it as food.