Soy (Glycine max (L.) Merr.) Is a herbaceous species belonging to the Fabaceae family.
From the systematic point of view it belongs to the Eukaryota Domain, United Plantae, Magnoliophyta Division, Magnoliopsida Class, Fabales Order, Fabaceae Family, Faboideae Subfamily, Phaseoleae Tribe and then to the Glycine Genus and to the Species G. max.
The term Phaseolus max L is synonymous. The terms are also synonyms: Dolichos soja L., Soja japonica Savi, Soja max (L.) Piper, Soja soja (L.) H. Karst., Nom. illeg., Soja hispida Moench, Glycine hispida (Moench) Maxim., Glycine soja Siebold & Zucc. and Glycine soja Hort ..
The term Glycine comes from the Greek γλυκύς which means sweet. The specific epithet max, according to Linnaeus refers to a Spanish plant.
The common word soya derives from the Japanese 醤 油 shōyu, which means “soy sauce” and which in turn derives from the Chinese 酱油 jiàngyóu.
Geographical Distribution and Habitat –
Glycine max is an annual species native to central-eastern Asia. The real soy (Glycine max) is not found in the spontaneous state; it is believed however that this is derived from Glycine soja which grows in a vast area extending into the Far East. According to other authors it derives from Glycine ussuriensis. Its cultivation was started in China at least 5000 years ago.
Today it is a species, with all its varieties and GMO forms, cultivated in most of the world. The top five producers are, in order, the United States, Brazil, Argentina, China and India. It should also be noted that production in non-Asian countries is largely destined to animal feed and export, while soybean remains a marginal component in the diet of local populations.
Soy is a herbaceous species with an annual summer cycle; this plant is entirely covered with brown or gray hair.
It has an erect or bushy habit, with a height between 70 and 130 cm.
The root system is a tap with a medium ability to penetrate the ground. The specific symbiont Rhizobium japonicum is present in the roots.
It has trifoliate leaves, except the first pair that is unifoliate.
The flowers are gathered in groups of 2-5 to form inflorescences (racemes) in axillary position in the varieties with indeterminate growth, while they are also placed at the apex in those with determined growth.
These are white or purple and are characterized by autogamous fertilization. Not everyone gives rise to fertile fruits: in fact, there is a high percentage of abortions.
The fruit is a hairy legume, often curved, of 3-8 cm, with 2-4 seeds with a diameter of 6-13 mm., Roundish or even more or less flat oval, yellow, brown, greenish or black, with ilo small and not very marked.
For the cultivation of soya it is necessary to take into account that it is a plant originally brevidiurna, that is to say that to flower it needs rather long nights. Today, however, in the varieties currently cultivated, it presents different behaviors towards light, so much so that many early varieties are photo-indifferent.
It is a plant that needs the availability of irrigation to complete the crop cycle.
In reference to the pedological needs, it is a broad-spectrum plant but too humid and too loose soils are not recommended. The most suitable pH is around 6.5; moreover, it is a plant that tolerates medium levels of salinity.
For the inclusion of a beautiful crop rotation, we remind you that soy is a plant that improves soil fertility and is a renewal plant with a spring-summer cycle. With very early varieties it can be used as an interlayer crop, after crops that soon release the soil (industrial pea, silage barley), with sowing by mid-June.
For its cultivation it is necessary to operate a rather early plowing and with refinement works carried out in a timely manner so as to have a perfectly leveled and administered seeding bed.
Where it has never been cultivated, the specific symbiont Rhizobium japonicum must be inoculated.
Soy is sown in rows 40-45 cm apart with a quantity of seed such as to have 30-35 plants per square meter for harvesting for late varieties and about 40 plants per square meter for those in second harvest.
For fertilizing, taking into account that, like other leguminous plants, it is self-sufficient for nitrogen (when the symbiont is present or inoculated), we must think about the contribution of phosphorus (80-100 kg / ha) and potassium in the case of deficient soils .
For the containment of weeds, once performed with chemical weed control, given the now known effects of this technique, we must begin to practice alternative ecological agro methods, such as false seeding, rotations, such associations as to decrease over time the concentration of herbs unwanted.
The most common cultivation treatments are rolling immediately after sowing and irrigation. If the soil is compact, weeding aims to aerate the soil to allow the aerobic bacteria to fix the nitrogen. Other occasional interventions can be the rupture of the crust, if the births struggle for this reason.
For the harvesting of this plant one intervenes when it is almost completely defoliated and has brown stems and seeds; it is carried out with wheat combine harvesters (lowering the bar as close to the ground as possible so as not to lose the lower pods (a bit like chickpea and lentils), with time between September, in the case of main cultivation, in October in the case of interlayer crops.
Average yields vary between 35 and 45 quintals per hectare.
For the harvest, the humidity of the seed must be around 12-14%; if higher, drying is required. For a good conservation the soybean seed, as an oil seed, must be stored with a humidity of 10-12%.
Uses and Traditions –
The first historical information on Soybeans date back to the 2nd millennium BC, although it was probably already known much earlier. Until the end of the nineteenth century it was cultivated exclusively in China. In the second half of the 20th century it had a remarkable development. The United States is the world’s largest producer. In Europe it is mainly cultivated in France and Italy (about 200,000 hectares; in 1990 there were about 400,000). It is one of the most important food plants for the richness of the seeds in oil (18-20%) and, above all, in proteins (40%).
In Europe, soy initially came as a study object in the botanical gardens (1737 in Holland, 1739 in France etc.) and only in the nineteenth century did cultivation begin. In America, soy is already mentioned by Benjamin Franklin in 1775, but its cultivation began significantly only in the early twentieth century.
Soy is applied in three main ways:
– for human nutrition, therefore based directly on the raw material of animal origin,
– for the feeding of farm animals, now predominantly of the GMO type,
– as a theoretically natural fertilizer, but now also predominantly of GMO origin.
Soy in human nutrition is a non-animal protein source, which can be used in many forms:
– soy flour, rich in protein and low in carbohydrates;
– soy milk, a protein-rich drink without cholesterol;
– soybean oil is an edible oil, containing a very balanced proportion of omega-6 and omega-3 fatty acids;
– tofu or “soy cheese”, produced from soy milk;
– miso, produced from a fermented soybean paste, used in soups and sauces, as a flavoring;
– soy sauce (or soyu), a sauce made from fermented soy beans and a fermented and aged roasted cereal;
– the tamari, a fermented soy sauce, with a more pronounced taste than that of the soyou;
– soya pulp, a product that remains after the filtration of tofu and soy milk, used as an ingredient in different cuisines;
– soy sprout, obtained by seed germination, is a nutritious and tasty ingredient known for its dietary properties;
– soy coffee which is a substitute for coffee used in the Friuli, Veneto and Trentino mountains (fasolin da Bondù) and in the Tyrol. It was obtained by roasting and grinding the seeds, then mixed with barley, also toasted.
In animal nutrition, Soya has assumed particular importance in recent decades in all species bred, both for polygastric animals such as cattle, and, above all, for monogastric species (birds, pigs, fish species, etc.), for the high biological value of the protein, rich in all essential amino acids, except methionine, which can easily be added with commercially available supplements.
Depending on the target animal, the percentage of soya in feed is very variable, being able to oscillate between 10 and 80%.
From the shredding of the seeds, especially for the production of oil, we have as a by-product (in the case of mechanical pressing) the soy panels, with a raw protein content of the order of 40 – 44%.
These are also used above all in the feeding of dairy cows and beef cattle and in particular of those animals fed on maize silage, whose proteins are less than needed and of limited biological value. However, the panels must be toasted before consumption to thermally inactivate anti-nutritional factors present in the seeds.
Another use of Soya is as a natural fertilizer, in particular with the technique of crop rotation, which has been documented since ancient times.
There are secondary uses of soy, in addition to the three main ones. For example, soy has been used, to a limited extent, as a textile fiber.
Of the health and ethical issues relating to Soybeans, the use of GM soybeans is obviously very important (which now accounts for 40 to 100% of the total, mainly in animal nutrition and which therefore moves directly to the human nutrition) that has raised a lively debate, both for the economic effects (positive for the greater productivity, negative for the dependence on a patent), and for the environmental and health effects (well tolerated or irrelevant according to the supporters, uncertain or heavily negative according to opponents).
It is recalled that the use of the herbicide glyphosate with the further known ethical, social and environmental developments is linked to the cultivation of GMO soybeans.
Finally, the debate on soy food properties is open. Proponents note that, being high in protein, it is an excellent meat substitute. Opponents attribute negative effects to different substances contained, which would have anti-nutritional effects (phytoestrogens, allergens etc.), especially with regard to damage to proteins taken from other sources or to iron and other minerals.
Furthermore, soy contains a series of proteins with high allergenic power (epitopes), such as: (Gly m 1; rGly 3; Gly m 4; Bet v 1; Bet v 2; Bet v 3; Bet v 4; Bet v 5; Bet v 6; m Gly Bd 28k-30k; Glycinin; Trypsin inhibitor; Beta-Conglycinin) these can cause food allergies, even serious ones, especially in early childhood.
From the point of view of human nutrition soy contains many minerals including phosphorus, iron, manganese, magnesium and potassium (useful in case of hypertension), and also vitamins such as vitamin A and many of group B.
Thanks to the remarkable presence of calcium (comparable to that of cow’s milk) it is a valid aid for osteoporosis or in general for bone health.
Among the important nutrients present in soy, there are essential amino acids and lecithin, which helps to counter cholesterol and reduce the risk of atherosclerosis and heart attack. Furthermore, the isoflavones contained in soy, also known as phytoestrogens, positively affect hormones (as they are very similar to them), thus being beneficial in premenstrual syndrome and in menopause. Finally, it is useful to keep glycemic peaks under control, so its use is recommended for diabetics. Unfortunately, today, a large part of the soya in commerce is GMO. It is therefore advisable to choose non-GMO organic soy (and derived products).
Preparation Mode –
Soy, in human nutrition, as well as being considered an excellent meat substitute, is much more digestible than other legumes.
The partner is found on the market both as a dry legume and already precooked. To prepare soy, if it is not pre-cooked, it must be kept soaked in water for several hours, better if it is all night. The soaking water will have to be thrown away while the soy will be cooked for about 2 hours or at least until it is soft. At this point you can proceed with the dressing and preparation of the final dish. Soy can be added to salads, soups, and can be used to make vegetable burgers or meatballs. From the grinding and roasting of the seeds, soy flour is obtained, a gluten-free flour that is used in bread dough, giving an unmistakable crunchiness, and in small doses even in desserts and biscuits.
Another soy-based product used by those who follow a vegan diet or by those who have problems with lactose is soy milk, which is obtained from the soaking of soy in water. Soybeans are also extracted from the seeds used in cosmetics, for the preparation of creams, and in the kitchen as a condiment. Contains many omega 6, but it is not recommended to subject it to high temperatures as it can be harmful.
Not to forget the bean sprouts much used in salads and ethnic recipes, such as spring rolls.
Soy sprouts are a valuable ingredient to add to salads. They are white filaments with a small inflorescence at the extremity, they have a fairly neutral taste so they go well with any vegetable or legume.
If you use soy sprouts in recipes, it is important to cook them (even for a few moments) in boiling water, as they contain phytates, substances that hinder the assimilation of some nutrients and disappear with cooking. Furthermore, cooking them avoids possible bacterial contamination.
Finally, soya lecithin, an excellent emulsifier and flavor enhancer, should be mentioned. Soy proteins are also used to increase the amount of protein in some dishes or to completely replace meat.
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– Treben M., 2000. Health from the Pharmacy of the Lord, Advice and experiences with medicinal herbs, Ennsthaler Editore
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Conti F., Abbate G., Alessandrini A., Blasi C. (edited by), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
Attention: Pharmaceutical applications and food uses are indicated for informational purposes only, do not in any way represent a medical prescription; therefore no responsibility is assumed for their use for curative, aesthetic or food purposes.