Generality
The "common" soy (in American soybean, in English soya bean ) is an annual herbaceous plant belonging to the family of Fabaceae (Leguminosae), Genus Glycine, Species max ; the binomial nomenclature of soy is Glycine max .
There are many varieties of soy, sometimes characterized by different colors. Furthermore, soy (like corn) is one of the food products most affected by genetic GMOs. On the other hand, to preserve its reputation, there are also many organic crops; unfortunately, however, from the analyzes conducted it seems that even these are not entirely free from transgenic contamination.
In addition to being a starchy legume (such as beans, peas, broad beans, lentils, lupins, chickpeas, etc.), soy is also classified as "oily seeds"; another legume with similar characteristics and even more rich in lipids, is the peanut.
Soybean oil is an extremely interesting product (especially from a nutritional point of view) and for this reason is included in the list of FAO (United Nations Food and Agriculture Organization).
The world's largest soy producers are: United States (35%), Brazil (27%), Argentina (19%), China (6%) and India (4%).
Production and Specifications of Soybean Flour
Soy flour is obtained from the dried (already dehulled) advanced residues of the pressing to separate the oil.
Soybean meal means a finely ground powder that is passed through a 100mesh sieve. NB . Soy flour should NOT be confused with soy in grains, which is crumbled coarsely.
In reality, there are many types of soybean meal, different mainly for the lipid content (degreasing) and for the level of protein denaturation. There is also a totally raw soybean meal which, obviously, does not depend on most of the processing; this is obtained using a technology called "Alpine Belle Mill"; it is not toasted nor defatted, it contains 18-20% of oil and less protein than the traditional one.
After squeezing, for the separation of the oil, and the grinding of the residue through hammer mills, the defatted soybean flour must be further refined ; this process takes place by adding a solvent (hexane) which is then completely extracted together with the solutes. The peculiar characteristic of this product is that, subsequently, the substrate is NOT subjected only to the classic roasting, but is introduced into a roaster-desolventizer (followed by a dryer and a chiller) in order to minimize the protein denaturation of the food and maintain the right solubility. This trick is not accidental; in fact, in this way it is possible to maintain a high index of dispersibility of the peptides, a necessary characteristic for some processing techniques such as extrusion. In addition to those already mentioned, today there are various soybean flour processing techniques such as, for example, Crow Iron Work (more efficient and economic) and desolventization-deodorization.
WARNING! There are no low-treated soya flours and others more treated, only the "raw" and "processed" ones. For those worked, the solventization phase is always the same, while the lipid content is determined by the additional addition of a fat fraction of the oil previously extracted (on average, for a total of 4.5-9%). Furthermore, the "raw" soy flour should not be confused with the "fat" one; a lipid level of 15% can also be obtained through the secondary addition.
Nutritional Features
Soy flour is used in the human and zootechnical food sector (feed), but also in agriculture; in the first two cases, the product has an important energy function (complex carbohydrates) and plastic (amino acids, many of which are essential), while in the third case it plays the role of fertilizer.
Soy flour is used by the food industries to produce various packaged foods (of all kinds), especially vegan foods (soy milk, tofu, soybean paste, etc.). The addition of soy flour to food carries out various functions, among which we recall:
- Prevents the aging of bread; this becomes stale, or rather stale, more slowly than normal (see the recipe for soy bread)
- Reduces the absorption of oil in frying
- Increases solubility and promotes the emulsion of the compounds, preventing them from separating
- It thickens as effectively as cereal flours.
From soy flour it is also possible to extract ONLY the proteins, known to have a High Biological Value and sold as a plastic food supplement (similar to those of whey, casein and egg).
| Composition for: 100g of Soybean Flour - Reference values of the INRAN Food Composition Tables | ||||
 | ||||
| Edible part | 100.0% | |||
| water | 7.0g | |||
| Protein | 36.8g | |||
| Prevailing amino acids | - | |||
| Limiting amino acid | - | |||
| Lipids TOT | 23.5g | |||
| Saturated fatty acids | 3.3g | |||
| Monounsaturated fatty acids | 5.7g | |||
| Polyunsaturated fatty acids | 13.3g | |||
| Cholesterol | 0.0mg | |||
| TOT Carbohydrates | 23.4g | |||
| Starch | 11.1g | |||
| Soluble sugars | 11.2g | |||
| Ethyl alcohol | 0.0g | |||
| Dietary fiber | 11.2g | |||
| Soluble fiber | - g | |||
| Insoluble fiber | - g | |||
| Power | 446.0kcal | |||
| Sodium | 9.0mg | |||
| Potassium | 1660.0mg | |||
| Iron | 6.9mg | |||
| Football | 210.0mg | |||
| Phosphorus | 600.0mg | |||
| Thiamine | 0.75mg | |||
| Riboflavin | 0.28mg | |||
| Niacin | 2.0mg | |||
| Vitamin A (RAE) | 0.0μg | |||
| C vitamin | 0.0mg | |||
| Vitamin E | - mg | |||
Soy protein isolates, quite common in sports, have also been shown to possess a certain cholesterol-lowering power; obviously, although with different mechanisms, from a therapeutic point of view they can act synergistically with other phytotherapic molecules of soy, such as phytosterols (also called phytoestrogens), viscous fibers, lecithins, omega 3 essential fatty acids (alpha linolenic acid) and antioxidants (isoflavones).
Among the various soybean flours there are also some "dietetic" types. The most widespread example is certainly that of " soy flour with lecithin " (up to 15%); highly soluble and strongly emulsifying, it also plays a metabolic role of the cholesterol-lowering type.
The available soybean meal is quite energetic. It provides up to 50% protein, many complex carbohydrates and, for "the joy" of the intestine (as well as the colic bacterial flora), as much as 5% of fibers (also, like lecithin, potentially hypolipidemic).
As for vitamins, soy flour is rich in thiamine (vit. B1), riboflavin (vit. B2) and niacin (vit. PP); with regard to mineral salts, potassium, calcium, phosphorus and iron stand out above all.
Soy flour DOES NOT CONTAIN GLUTEN and, if used on the one hand it does not lend itself to bread-making (it must instead be added in percentage to gluten flours), on the other it is perfectly tolerated by coeliacs.
Soy flour is recommended in case of metabolic diseases, thanks to the high content of essential fatty acids of the omega 3 group. It can also favor the reduction of hypertension, hypertriglyceridemia, complications related to type 2 diabetes mellitus and, thanks to the presence of other beneficial molecules, of total cholesterol, especially of LDL (bad). It is however essential to remember that soy flour is highly caloric and that its use must take into account any excess weight of the consumer.
Containing phytosterols, soy flour (such as red clover) is also used in the treatment of climacteric syndrome. It is a good adjunct to other therapies which, depending on the case history, can determine a significant reduction of the related symptoms or be almost useless.
Gastronomic Aspects of Soy Flour
Soy flour is used in the kitchen especially for some vegan type recipes. In this regard I suggest to consult Alice's video vegan recipes.
However, it is a good thickener for cooking surfaces (eg for scallops). Mixed with wheat (about 5% of the total) it favors the preservation of the bread and tends to improve its leavening; on the other hand, at higher percentages it worsens it.
Soy flour also lends itself to the smearing of foods to be fried and, always together with wheat flour, makes excellent batters. Moreover, especially the one added in lecithin, it has an excellent emulsifying power.
The most used soybean meal in Japan is the "Kinako".
Recipes with soy flour
